# Dom's workshop build



## DomD

Planning on building a new workshop this summer. This will be heavily based on Mike's design but I have a few questions to ask before getting into building.

First off this is the site I want to build on (it is 'L' shaped but the pano stretches it out'):





The ground here was recently levelled so while it isn't completely flat not too much should need to be removed to get it flat. The trampoline and pile of branches will of course go.
As for size I have not fully decided but would be able to fit a 12' by 16' building on this site while remaining 2m from the borders.

I want to be able to do both woodworking and electronics shop and think because of the dust I will probably have to go for two rooms: that could potentially mean making the actual woodwork area only 12' by 10', thoughts on whether that is big enough (I know this is subjective)? The other option is having an 'L' shaped building to fit the space with the electronics area in the part coming out however I am concerned this is overcomplicating things for someone who has never done anything like this before.

For the base I plan to lay a concrete slab: I was wondering what the insulation options are for this as would ideally like the shop floor just to be concrete. The site is very inaccessible so I will definitely need to hire a pump if going this route; I may, in the end, pay for a builder to do this job as I am slightly worried about getting it level. Is this definitely the way to go or are concrete piers suited to this sort of job?

For the roof, I was initially going to do a cold mono-pitch roof with EPDM but have been considering a gable/hip for aesthetics. I am assuming this is going to be much harder work but am going to do the whole thing in CAD before to get all the angles etc. Are there load tables for these types of roofs and information on what type of joist brackets to use?

I also really like the look of clerestory windows and the light they provide but am worried that would complicate the roof framing loads especially as I haven't done roof framing before.

Just a couple of questions about Mike's design: firstly, I have seen others adding an extra layer of OSB/ply between the wall framing and breather membrane, is this not required? Secondly, how are the galvanised straps laid accurately and what sort of dimensions are required? A link to a product would be really useful.

I will pay an electrician to do the electrics but was wondering when these are installed (before insulation?) and what pipe size/diameter I should put in the slab for the cable.

Finally has anyone used 'Cedral Lap' style cladding and is there any low-cost cladding you recommend?

I appreciate this is a really long post and I have probably missed some details but thank you for any advice. Feel free to ask for any more info.

Many thanks, Dom


----------



## MikeG.

Welcome Dom. 

That looks like a great project you're planning, although with all that available space, and the need for two separate rooms, I think you might regret going to all that trouble and ending up with a space which is a bit constrained. My first suggestion is to do a proper scale drawing, including your bench, and machinery, tool storage, wood racks and so on, and see if you can make it work on paper for the sorts of projects you envisage doing. Remember, I don't think I've ever heard anyone say "I wish my workshop was a bit smaller".

Have a look at my workshop build,here. That might answer a few of your questions. Insulation under the floor is easy. I'll tell you your roof timber sizes when the time comes, and there is no need for any specialist brackets or anything like that for the roof. The strapping is just simple universal galv ms banding. Wall construction should follow the principles I set out in my two threads in my signature. Don't very from that, although obviously there are a multitude of external finishes one can use in place of the feather edge boards I suggest. The only correct position for the OSB is where I've shown it, and adding in more elsewhere could compromise the performance of the wall and the longevity of the building.

I'd steer clear of clerestorey lights. Your building is too small to justify them, and they cause a real structural complication , which will head towards structural engineer's territory if you do end up with an L shaped plan form. They are also a really attractive target for thieves, as they're difficult to protect. There is a standard plastic duct for electric cables, but you really only need it to bring the cable into the building. Two or three feet. The armoured cable to the building doesn't need to be in a duct. Maybe look out for an off cut on Ebay.

Anyway.........this all sounds fun. Time for you to get drawing........


----------



## DomD

Thanks for all that information Mike, reading through your build was especially helpful. 
I think you may be right about the space: I may end up just going for one shop with an electronics bench in it that can be covered or if I can stretch the budget adding a couple extra square feet.

One way to save on cost would be doing the base myself though I am a little concerned about getting it flat; would you say this is something worth paying for?

Now I have seen your build the strapping makes much more sense; I also think I might copy your blocking so the cladding doesn't stick out too much.

I will stick to your wall construction.

I was actually thinking of clerestory lights back on my monopitch roof, though I have seen them on gable style roofs in buildings of similar size to mine such as "Sean's shed" which has plans online (I am unable to link at the moment):




I would definitely not be doing an L and clerestory lights and understand the additional complexity it would bring (and cost!).

For the cable I will check eBay: may also see what my electrician says.

Will get drawing now! Thanks for all the help.


----------



## DomD

I have attached an image of an initial 1:24 floorplan which seems to look plausible but may seem much smaller in person (and will change depending on the size of machines I get). I will need to go and peg out the area to visualise the space.

After looking at having the two rooms I ended up just putting in a small separator wall: will need to see if this is adequate for dust control.

Just another question about your design: I realise you used OSB as the vapour barrier for the build - would plywood work too as it has layers of glue or would a separate vapour barrier need to go below the plywood? 
Thanks for all the help so far,
Dom


----------



## sunnybob

I have 12 x 10.
ITS NOT ENOUGH!!!!!!!!
:roll: :roll: :roll: :roll:


----------



## MikeG.

I assume you're left handed?

Couldn't you have another stub partition opposite the one behind your bench? That way, you could have a plastic curtain or similar to draw across the opening when you need the other side to be dust-free?

Looks to me like you'll have about 3.8m x 3.0m for woodworking. Is that enough? Making the building a metre longer would make a substantial difference.


----------



## DomD

MikeG.":3s2j78hl said:


> I assume you're left handed?


No actually, is it my drawing style?



> Couldn't you have another stub partition opposite the one behind your bench? That way, you could have a plastic curtain or similar to draw across the opening when you need the other side to be dust-free?


I could do, I'm just worried by partitioning the whole section off it will make the main area feel more enclosed and leave less space to assemble larger items. 
I hope with most of the dust being made over on the left it should be ok, even so I doubt I will be making lots of dust at the same time as working on electronics.
Thanks


----------



## sunnybob

Its not just the machines, you have to have space to store your wood and offcuts. That alone can take a couple square metres.
I'm severely limited on what stock i can buy purely because i cant store it.


----------



## AES

FWIW, I agree with someone above who said "I've never heard of anyone complaining that their work shop is too big"! So if you can, add that metre (or even 500 if you can only get away with that much).

Re the dust, I'd strongly recommend an air filter as well as the extractor shown. If you can hang it from the ceiling, machine inlet facing the dusty side of the shop, outlet facing a window, or if not possible as in your drawing, at least facing the door. There are several on the market, I bought the Record Power 400, and it works very well in my cellar, hung up almost flush to the ceiling (similar to your drawing, not many openings to the outside in my cellar). The machine is quiet, has 3 speeds, and best of all, has a 1, 2, and 4 hour timer - but as said, there are other makes.

And as said, don't neglect the good effect some sort of floor to ceiling curtain can have - my wife suffers from COPD and stuff like the washing machine etc, is in the cellar too. So she's in and out of there too. I find a couple of cheapo shower curtains sewn together and hung from the ceiling separating "my side" from her side", coupled with running the Record on auto timer does a lot (but NOT all please note) to reduce airborne dust. I don't have a chip extractor but only run each hand tool connected to a shop vac.

HTH, good luck with the shop build, there's plenty of people on here who have MUCH more knowledge than me.


----------



## DomD

sunnybob":1mfkvtuc said:


> Its not just the machines, you have to have space to store your wood and offcuts. That alone can take a couple square metres.
> I'm severely limited on what stock i can buy purely because i cant store it.


Yeah, I have factored some space for that into my initial drawing but can imagine running out quickly



AES":1mfkvtuc said:


> Re the dust, I'd strongly recommend an air filter as well as the extractor shown. If you can hang it from the ceiling, machine inlet facing the dusty side of the shop, outlet facing a window, or if not possible as in your drawing, at least facing the door.
> And as said, don't neglect the good effect some sort of floor to ceiling curtain can have - my wife suffers from COPD and stuff like the washing machine etc, is in the cellar too. So she's in and out of there too. I find a couple of cheapo shower curtains sewn together and hung from the ceiling separating "my side" from her side", coupled with running the Record on auto timer does a lot


That sounds like a good idea regardless of whether I go for one room or too seperate rooms.

I do have space for probably up to 12x20 (with the 2m boundary on each side) so maybe I should invest in the larger room initially even if that means getting set up with fewer tools after? I am drawing a floorplan for this now.

Thanks for all the feedback and help.


----------



## MikeG.

DomD":2lbway0v said:


> MikeG.":2lbway0v said:
> 
> 
> 
> I assume you're left handed?
> 
> 
> 
> No actually, is it my drawing style?
Click to expand...


No, you've shown the vice at the "wrong" end of the bench. And if you show it at the normal location, your bench is pushed into a corner where you don't want it to be for right handed work.


----------



## screwpainting

Its a nice place to be Dom,new shop, stuff to plan, stuff to buy, its what men need and deserve to be doing. If it were me, I would hold fire on planning each work area too hard and fast and make as much of the shop as possible moveable on wheels so as to be able to adjust the geography of things as you go along. I don't think I would ever have fixed areas again, too inflexible. Some of these new cabinet designs that have a table saw, thicknesser, router etc that all flip over when not in use make so much sense when you think about it. As for dust, its all been said before but in addition to all the other things you can do to have a dust free shop. A simple but very powerful wall vent fan is an amazingly quick way to completely remove the fine stuff. I did a smoke test in my little shop and with a door held ajar at the opposite end of the room to the fan, I saw a corridor of fresh air in which you can work and the smoke cleared completely in about a minute. No guessing, you can actually see the clean air area. I would not be without that fan, I put it in initially to remove kiln fumes as I also make/made tiles and you most definitely don't want to breathe in the crud from that process. Another thing I would consider is additional floor area outside with a pull out canopy of some sort, I stuck an awning from one of my old motorhomes on the front of my shop over the door, three and a half meters wide I think, I cant tell you how handy that has been, I wouldn't want to be without that either, beer in the rain or out of harsh sun, sussing stuff out, it just works, trust me .
Good luck with it all, looks a lovely site for it.


----------



## DomD

MikeG.":27uo93st said:


> DomD":27uo93st said:
> 
> 
> 
> 
> 
> MikeG.":27uo93st said:
> 
> 
> 
> I assume you're left handed?
> 
> 
> 
> No actually, is it my drawing style?
> 
> Click to expand...
> 
> 
> No, you've shown the vice at the "wrong" end of the bench. And if you show it at the normal location, your bench is pushed into a corner where you don't want it to be for right handed work.
Click to expand...

Ah, I was sort of unaware of that as a standard but now I have looked it up it makes sense. Thanks for the heads up - I will change it when redesigning.


----------



## DomD

screwpainting":2lz3yfll said:


> I don't think I would ever have fixed areas again, too inflexible. Some of these new cabinet designs that have a table saw, thicknesser, router etc that all flip over when not in use make so much sense when you think about it. As for dust, its all been said before but in addition to all the other things you can do to have a dust free shop. A simple but very powerful wall vent fan is an amazingly quick way to completely remove the fine stuff.


Good point about the movable tools: the reason I included the long chop saw station is that I can store movable tools underneath it (shown in plans); the chop saw will also be useful for making quick crosscuts as I won't have to wheel out the table saw. I will look into getting a fan.



screwpainting":2lz3yfll said:


> Another thing I would consider is additional floor area outside with a pull out canopy of some sort, I stuck an awning from one of my old motorhomes on the front of my shop over the door, three and a half meters wide I think, I cant tell you how handy that has been, I wouldn't want to be without that either, beer in the rain or out of harsh sun, sussing stuff out, it just works, trust me .
> Good luck with it all, looks a lovely site for it.


Would need to look into planning permission, but sounds like it might be an idea. Do you extend the concrete out to the awning?

Speaking of the site the trampoline is down today, now just to burn the garden waste:





Thanks for all the advice so far.


----------



## MikeG.

If you're away from your boundary, and if you aren't in a National Park, AOB, World Heritage Site etc, then you don't need planning permission for what you've drawn so far, so long as the roof doesn't get too tall.

I hate movable machinery, and built a big enough workshop such that I din't need to have them movable. A small workshop with lots of machinery forces you into having it mobile. When you've a blank sheet of paper, you've got the choice, but you should be making those fundamental sorts of decisions on paper, and not when you are standing in your new workshop.


----------



## mindthatwhatouch

Hi,
Yes to the has someone used cedral cladding question. I used it as needed to be fire resistant, next to boundary. I bought some surplus from someone, which did most of the job, Steve maskery’s fine workshop used a similar sheet type material that probably works out cheaper.
yep-it-s-another-workshop-design-questions-t84326-75.html#p1005159

Also I stuck some celotex under the concrete slab. If you go down that route.

Roof covering wise I can recommend the metal tiling system I used, (decra or equivalent) really don’t understand why you don’t see more of it around.

Good luck with the build.


----------



## DomD

mindthatwhatouch":2ot3smdj said:


> Hi,
> Yes to the has someone used cedral cladding question. I used it as needed to be fire resistant, next to boundary.


It looks alright in those photos and seems to be much more affordable than timber; can always decide on cladding at a later date.



mindthatwhatouch":2ot3smdj said:


> Also I stuck some celotex under the concrete slab. If you go down that route.
> Roof covering wise I can recommend the metal tiling system I used, (decra or equivalent) really don’t understand why you don’t see more of it around.


What would be the layering of that? Did you do hardcore->sand->celotex->concrete or did you put concrete down first, then screed? I am worried the heat would just be lost through the sides of the slab if I do that, not sure if it is worth it for the extra digging required.



MikeG.":2ot3smdj said:


> I hate movable machinery, and built a big enough workshop such that I din't need to have them movable. A small workshop with lots of machinery forces you into having it mobile. When you've a blank sheet of paper, you've got the choice, but you should be making those fundamental sorts of decisions on paper, and not when you are standing in your new workshop.


Yeah, definitely why I am leaning towards the larger 20x12ft setup; at my current open workspace I have got used to having everything in its own space and ready to go. 

I was wondering if there was any particular method of working out heaters required for the space and what radiators work best (will need to be electric of course). I will have double glazed uPVC windows and doors so that should help around the openings but I suppose the floor will be the main heat loss area if uninsulated.

Finally is there any reason to use 400mm spacing over 16" if I am not using plasterboard?
Thanks


----------



## Peterm1000

I would think seriously about having a mini-shed backing on to the main workshop to hold the dust extractor (which you could turn on and off with an Alexa enabled plug and an Amazon Echo - no remote controls). I did that and not only does it create some space in the workshop, it also means you are extracting dust outside so you don't have to worry about filtration. The only downside is not being able to see how full the bag is.


----------



## DomD

Peterm1000":3fmmemoj said:


> I would think seriously about having a mini-shed backing on to the main workshop to hold the dust extractor (which you could turn on and off with an Alexa enabled plug and an Amazon Echo - no remote controls). I did that and not only does it create some space in the workshop, it also means you are extracting dust outside so you don't have to worry about filtration. The only downside is not being able to see how full the bag is.


As in still connected to the building, or a whole seperate shed? I was already thinking about a mini shed sticking out (same building) for a couple of bikes. Would help with noise too.


----------



## DomD

MikeG.":211xat4k said:


> Looks to me like you'll have about 3.8m x 3.0m for woodworking. Is that enough? Making the building a metre longer would make a substantial difference.



This is the building extended a further 1.2m (4ft).




I have to agree it does give a lot more space for woodworking with almost an 8ft*10ft open space in the middle: I will just need to see how much the extra base concrete will cost me. I have the stakes and line so will go up and try to visualise the size.
I noticed in your build you placed your PT in the centre, did you find that to work well or to be an obstruction?

I also hope to be able to store sheed materials in the area above the electronics area where I don't mind having a lower roof.

Has anyone used skylights on their workshops; seems like they may help light up the area more (even though I have already put three windows in).

Dom


----------



## MikeG.

My PT has never moved since I built the workshop, which shows it is in the right place, and not in the way. I have room in the main part of the workshop to have an 8x4 sheet of ply on stools, and to be able to work all around it.

You might have seen I overhung my roof at the rear by about 3 feet. This forms a really useful storage area, and eventually will have a proper base and racking. The more stuff you can get out of your workshop, the better. Dust extraction is obvious, and timber racking too. I'm watching a chap in another thread building a small set of shelves, and really struggling just through lack of space. He has to take it out to turn it around. You really don't want to go to all the trouble of building a fine new workshop and then find yourself struggling to move in it.


----------



## MikeG.

Three rooflights at £350+ a time will pay for an extra 1200 or 1800 on the length of your building..........and further, they're a nightmare to keep secure. At least with windows you can put an internal shutter in, or some bars. Your proposed building is very small, and will be well serviced by 2 windows (mine is fine with just one). Windows cost you wall space, which means less storage. I suggest you keep to one window for each side of your 2-bay workshop, forget the rooflights, and just make the whole thing a bit bigger.


----------



## DomD

Oops forgot to attach the plans: done now.



MikeG.":3vpssphg said:


> Three rooflights at £350+ a time will pay for an extra 1200 or 1800 on the length of your building..........and further, they're a nightmare to keep secure. At least with windows you can put an internal shutter in, or some bars.


If I am using uPVC windows and doors with rated locks I wonder what that means for insurance? I will need to look into it online. I guess I won't do rooflights then. The three windows at the moment are for: main area large window, window to allow long cuts on mitre saw, window in electronics area for laser cutter fume extraction and airflow when soldering. The two latter are going to be small, so hopefully shouldnt inflate the price too much.

I will definitely do an overhang and as I said maybe a small 'extension' at the front for bikes and dust. 
Dom


----------



## MikeG.

I'd do away with the window for the long cuts on the mitre saw, and build something yourself. It only needs a top-hung hatch on the outside and a sliding hatch on the inside. That should be a lot stronger and safer than a window, and much cheaper too.


----------



## DomD

MikeG.":87uqf2fx said:


> I'd do away with the window for the long cuts on the mitre saw, and build something yourself. It only needs a top-hung hatch on the outside and a sliding hatch on the inside. That should be a lot stronger and safer than a window, and much cheaper too.


Oo thats a good idea: I can also make it seamless as I think three windows on the front may be a bit much.

I am beginning to draw up my plans in CAD am wondering what sort of joist and rafter sizes will be needed for the 20'x12' size - I also want to use some of the joists for sheet material storage so will that mean any increace in size?
The walls I am just using 16'' on with 47mm x 100mm treated timber. Is it worth using C24 for everything or shall I stick to C16 for the walls?
And is there any way of calculating the required lintel size? My biggest opening is the 1200mm doors.

Thanks


----------



## MikeG.

Just use 145x47 at the moment for both joists and rafters.....and have a look at mine with the missing joists and a structural ridge, used to make the loft accessible internally. Don't worry about the timber strength rating, and your wall studs can be at 600 C's if you double up the top plate.


----------



## DomD

MikeG.":2r5h0i9h said:


> Just use 145x47 at the moment for both joists and rafters.....and have a look at mine with the missing joists and a structural ridge, used to make the loft accessible internally. Don't worry about the timber strength rating, and your wall studs can be at 600 C's if you double up the top plate.


Wouldn't 600C's for studs and joists mean cutting off 2cm/4cm of each standard 2x4 piece? Wouldn't 610C's make more sense (or 16")?

Also sorry for repeating a previous question but does exterior grade ply act as a vapour barrier similar to OSB? Hoping to clad the inside with it and dont want to put down two layers of sheet material.
Thanks


----------



## MikeG.

I'm not following. The length of your studs is irrelevant to their spacing. You'll be cutting all your studs anyway. And yeah, metric or imperial isn't an issue.......set out stud spacing according to your sheet sizes. Don't make assumptions about your sheet sizes, either. Some ply is metric, some imperial. Some OSB is metric, some imperial, although I think imperial is commonest.

Ply is usually way more expensive than OSB, which is why I suggest the latter, but ply is OK if you want to use it. Be cautious of the cheap stuff, and in particular watch out for sheathing ply, where finding something flat can be a real struggle. They can also delaminate. But if you've got a source of decent ply at a better price than OSB, then that's fine. It isn't as good a vapour barrier as OSB, but it's good enough for a workshop. It wouldn't be good enough if you were regularly doing a "wet" activity in the space.


----------



## DomD

MikeG.":6y8ycd7h said:


> I'm not following. The length of your studs is irrelevant to their spacing. You'll be cutting all your studs anyway. And yeah, metric or imperial isn't an issue.......set out stud spacing according to your sheet sizes. Don't make assumptions about your sheet sizes, either. Some ply is metric, some imperial. Some OSB is metric, some imperial, although I think imperial is commonest.



Ah sorry '2x4' sounded like I meant studs but I was actually referring to sheet material (which is usually 4x8, my mistake). All sheet material in my area is rounded off imperial (e.g. 2440x1220) so I think 610 spacing would work well - as long as that is enough to support the load of the roof.
Thanks


----------



## DomD

I am having second thoughts about using the concrete as the floor: on one hand, it would be nice to be able to do occasional welding on it but I think floor insulation is going to be a pain if not on top of the poured slab. I also don't really want to have to step up.
Are there any good methods of isulating the bottom of the slab and sides or shall I just use PIR over it?
Insulation is important as I plan to heat it year round.
Thanks


----------



## MikeG.

You can insulate under a slab. It just means a little more digging, that's all.


----------



## RobinBHM

I built my 18 x 9 shed on pads

I made 12 concrete pads, 4 rows of 3. I then used 4no 120mm x 78mm I beam steels I then used 4 x2 joists, which allows space for 70mm insulation. For me it saved moving so much ballast down the garden. Perhaps not as solid as a concrete base, but still very solid and means a suspended timber floor which is knider on the feet.


----------



## DomD

MikeG.":1vwbq3vo said:


> You can insulate under a slab. It just means a little more digging, that's all.







So can I confirm this is what you are suggesting, with the PIR (kingspan) right up against the earth under the slab. This will insulate the bottom of the slab but from looking online most heat is lost throgh the sides. Also, will the kingspan be fine under the weight of 150mm concrete?



RobinBHM":1vwbq3vo said:


> I built my 18 x 9 shed on pads
> I made 12 concrete pads, 4 rows of 3. I then used 4no 120mm x 78mm I beam steels I then used 4 x2 joists, which allows space for 70mm insulation. For me it saved moving so much ballast down the garden. Perhaps not as solid as a concrete base, but still very solid and means a suspended timber floor which is knider on the feet.


Definitely an option but I think I am pretty set on a slab now especially as I have some heavier machinery.
Dom


----------



## MikeG.

DomD":3v8biatu said:


> ......... will the kingspan be fine under the weight of 150mm concrete?.......



Yep.


----------



## DomD

I redrew (once again) the floorplans: this time going to the full horizontal width of my area (14ft):





Some notes about this design:

There is no space allocated for a planer thicknesser yet, maybe it would work well just below the sheet material storage?
I see a lot of small workshops with a big table saw cabinet; is there any point in this rather than a 'roll out station' (or rather do you think the practicality outweighs the space costs)?
I feel like the mitre/cross cut station may be a bit too large; is there anything I could move around so it maintains its cutting length if required but another tool/machine could be used in that area?
Is there any point of having a 'proper' dust collection system in this size an workshop or will a cyclone and shop vac on wheels suffice?

As you can see I went for the seperate room and think this is what I will stick with just due to the risk of dust.



MikeG.":1flok9gw said:


> Ply is usually way more expensive than OSB, which is why I suggest the latter, but ply is OK if you want to use it.


I will think about this: I much prefer the look of plywood and really dislike the look of OSB, I know it can be painted but it still doesn't hide the texture. If I were to use plywood it would be WBP B/BB external grade stuff that apparently is less likely to delaminate.

This is my BOM so far for the base:




The subbase type-1 costs loads but I guess there is nowhere else where I will be able to get the amount of hardcore required (and deliver it). Other than that the concrete and pump are very rough estimates based on what I can find online.

I have no idea how I will get the hardcore and sand up to the site: I guess just bit by bit in a wheelbarrow? Has anyone tried the double wheeled wheelbarrows? Might help as this is the slope I need to get it up (from an upstairs window!).





Finally, any reccomended tools for the job? I use bosch wireless tools so am thinking about the wireless circular saw but not sure as of yet about mitre saw or nail framing nailer.

Thanks, Dom


----------



## MikeG.

£10 will buy you one bag of cement and a wheelbarrow of sand. That's seriously unrealistic. You'll buy sand and ballast by the bulk bag, for about £45 each.

Mortar is mixed at the site of the sand, and then barrowed across to where you need it. No other way works at all. And don't ever buy anything other than a builder's wheelbarrow. Again, nothing else works. If you are laying the bricks yourself, you'll do well to use more than a barrowful of mortar in the morning, and another in the afternoon, and pushing that down your garden is no hardship. In fact, if you're sensible, you'll use half a gauge of mortar at a time, and leave the other half in the mixer to rejuvenate with a bit of water.......so you'll only be pushing half a barrowful at a time. 

Depending on your ground conditions, you may well not need anything below your slab other than sand blinding (to protect the DPM). Hardcore or Type1 /2 are for consolidating soft or wet ground, or for building up levels. If you don't have those conditions, then don't use it. As soon as spring arrives, you should dig yourself a trial patch in the area of your workshop, and see what the soil conditions are like. Ideally you'll remove the topsoil and bed directly onto the top of the subsoil, and if that is firm enough, just put an inch of sand over everything.


----------



## DomD

MikeG.":3t1yx6py said:


> £10 will buy you one bag of cement and a wheelbarrow of sand. That's seriously unrealistic. You'll buy sand and ballast by the bulk bag, for about £45 each.


Ok, just checked and yes, for two courses a bulk bag each looks like enough; not sure why I put 10 there, didn't even search it. I will probably be laying some myself but also have some help from a bricklayer friend so can check the details with him.



MikeG.":3t1yx6py said:


> Depending on your ground conditions, you may well not need anything below your slab other than sand blinding (to protect the DPM). Hardcore or Type1 /2 are for consolidating soft or wet ground, or for building up levels. If you don't have those conditions, then don't use it.


That would be good as it could take quite a few full days to move all that type 1 up the hill (and adds ~£300). I will definitely check.

Dom


----------



## mindthatwhatouch

mindthatwhatouch":14bwfrb2 said:


> Also I stuck some celotex under the concrete slab. If you go down that route.
> Roof covering wise I can recommend the metal tiling system I used, (decra or equivalent) really don’t understand why you don’t see more of it around.


What would be the layering of that? Did you do hardcore->sand->celotex->concrete 
Yes to that order.

I am worried the heat would just be lost through the sides of the slab if I do that, not sure if it is worth it for the extra digging required. Put an upstand of celotex around the perimeter.


----------



## MikeG.

mindthatwhatouch":25dsmnle said:


> .........Put an upstand of celotex around the perimeter.



That's not possible without either a strip footing, or a stepped slab/ raft edge ("toe").....and the latter requires a structural engineer. 

Celotex can't be left exposed to the elements, so it needs to be behind a skin of something. That skin needs something to stand on.......thus the foundation. The whole point of this technique of mine is to make the build simple enough that novices can build it, but of course, there are alternative designs available to those up for strip footings, cavity masonry work, vertical DPM's lapping with the DPC, and ground bearing slabs. Something as seemingly simple as an upstand of Celotex around the perimeter of the slab has fundamental implications for the entire design, and for the ability of 95% of the population to build it.


----------



## DomD

MikeG.":2br1b69l said:


> mindthatwhatouch":2br1b69l said:
> 
> 
> 
> .........Put an upstand of celotex around the perimeter.
> 
> 
> 
> 
> That's not possible without either a strip footing, or a stepped slab/ raft edge ("toe").....and the latter requires a structural engineer.
Click to expand...

Is the heat loss from the sides of the slab substantial enough to justify the insulation on top of the slab?

I am currently CAD framing and wondering how the interior room would be done, this is what I have at the moment:





How would the interior room frame be attached to the main frame and how would this interact with the internal OSB (/ply)? I assume it cannot be recessed into the OSB as this would breach the vapour barrier?

Thanks


----------



## MikeG.

You can put Celotex underneath the slab, or you can put it above it. I don't have either, and my workshop is plenty warm enough with a small electric heater, which isn't on all the time I'm out there in winter.

The junction between an internal wall and an external wall is easy. Build the external wall first, complete with OSB, then build the internal wall inside it. You need extra noggins in the external wall placed to enable the internal wall to be fixed through to it.

BTW, I suggest 3 course of bricks, so that you can have a skin of 50mm blockwork inside the plinth. Not only is this a little extra insulation, but more importantly, it enables the outer cladding to meet the plinth properly, without a 60mm gap/ overhang.


----------



## DomD

Thanks for the advice on the insulation and internal wall.



MikeG.":3164xn90 said:


> BTW, I suggest 3 course of bricks, so that you can have a skin of 50mm blockwork inside the plinth. Not only is this a little extra insulation, but more importantly, it enables the outer cladding to meet the plinth properly, without a 60mm gap/ overhang.



I saw this in your build and agree it seems like a good idea: does using this method mean you also do not have to cast the metal straps into the concrete but can instead wrap them under the blockwork? Anther point on bricks: what type should be used? Engineering? Facing?

Thanks


----------



## MikeG.

Yeah, casting them into the slab is wishful thinking really, especially on an amateur DIY build. Screw them to the face of the blocks. Bricks can pretty much be anything you like the look of. There is absolutely no need for engineering bricks.


----------



## DomD

I have started work on the CAD model: the walls (no windows yet) and roof are in (not the joists yet).






The roof is at 30 degrees, are there standards or better looking angles I should stick to?

All of the walls use 610mm spacing optimised for as little wastage of internal sheathing (rather than the usual external, meaning the offsets are non-standard) which means the gable end studs and rafters don't line up but I have read this is fine as I have a double top plate; is that correct? A side view for demonstration:




After looking into lots of wall construction techniques I have found lots have exterior sheathing - why is this not required for a build like this?

At the moment I have 650mm overhang at the front and back and 300mm gable overhang: I would like more at the front and back but will need to see if they fit.

The birdsmouth currently has a heel of ~42mm and a seat of 72.5mm shown here:





Hopefully that all looks okay: I am on to the joists tomorrow.

Thanks


----------



## DomD

I was thinking I could maybe do something like this where the red area has a high ceiling (with raised rafter ties) with no storage above it and the green area has standard roof joists resting on the double top plate:




The walls already mean the minimim roof height would be 2400mm+ so the lower roof in the electronics/enterance area wouldn't be a problem. This way the workshop area would feel more open and the storage above the other area could be easily accessed. How high can raised rafter ties be above the top plate?

As I was doing the gable ends I realised they were not in full contant with the rafters above - is there a proper way to fix this?




Thanks, Dom


----------



## Peterm1000

Dom,
My workshop is 14 foot square. I cannot imagine sub-dividing that as it is already pretty small. I have a table saw, mitre saw station, planer thicknesser, sanding station, pillar drill, bandsaw and workbench. My extractor is in a mini shed that backs onto the workshop. The two main recommendations I would make are:

1. Put EVERYTHING on wheels so you can fiddle about with the layout / change things as you change tools. 
2. Put up battens on every wall at even distances for a French cleat system. I have most of my tools on the walls and again, French cleats give the most flexibility.

Good luck!


----------



## MikeG.

DomD":3vq038rd said:


> ........ How high can raised rafter ties be above the top plate?....Thanks, Dom



This is a rule of thumb answer only, but in the bottom third of the rafter length. They can of course be anywhere on the rafter, with a declining influence on the spreading forces on the walls the further up the rafter they go, but I wouldn't advocate anything over a third of the way up the rafters without a structural engineer's say-so.


----------



## MikeG.

DomD":20q1hgsl said:


> ......As I was doing the gable ends I realised they were not in full contant with the rafters above - is there a proper way to fix this?



Halving joint. It's unimportant, though. They're only there to fix OSB to.


----------



## DomD

Peterm1000":1g91wq32 said:


> Dom,
> My workshop is 14 foot square. I cannot imagine sub-dividing that as it is already pretty small. I have a table saw, mitre saw station, planer thicknesser, sanding station, pillar drill, bandsaw and workbench. My extractor is in a mini shed that backs onto the workshop. The two main recommendations I would make are:
> 
> 1. Put EVERYTHING on wheels so you can fiddle about with the layout / change things as you change tools.
> 2. Put up battens on every wall at even distances for a French cleat system. I have most of my tools on the walls and again, French cleats give the most flexibility.
> 
> Good luck!



Unfortunately, I have to have somewhere to store my electronics so the subdivider is necessary, I am planning at the moment to do some sort of permanent mitre station/workbench with multiple wheeled tools such as the planer thicknesser and table saw underneath. The french cleats are a great idea, definitely a better solution than just nailing holders into the wall.



MikeG.":1g91wq32 said:


> This is a rule of thumb answer only, but in the bottom third of the rafter length. They can of course be anywhere on the rafter, with a declining influence on the spreading forces on the walls the further up the rafter they go, but I wouldn't advocate anything over a third of the way up the rafters without a structural engineer's say-so.


And I suppose a structural ridge like this would be straying into structural engineer's territory too?




If so I guess I will just have a slightly higher roof in the main room than the electronics area (1/3 up).

Looking at Dan's Shed over on thewoodhaven2 I noticed he braced his walls before the cladding went on - is this recommended or does it just provide a little extra stability?
Finally, I have seen that a surrounding ditch of shingle is recommended for drainage: how deep should this be and does anything need to be under it or can it just drain into the soil?

Thanks all,
Dom


----------



## DomD

Another small question: if I plan to put tiles (not decided which) on the roof should there be a layer of OSB below the battens? If so I assume the roofing structure should be: tiles -> battens -> membrane -> OSB -> joists and insulation -> interior OSB/ply (vapour barrier).


----------



## MikeG.

No. Any OSB up there is just as a substrate for stuff such as EPDM or felt which needs it. If it is a tiled roof, or slate, then it would just be done in the conventional way with battens and membrane on the rafters.


----------



## AJB Temple

My thoughts. Don't be afraid of doing the concrete yourself. It is dead easy. All you need us framing boards around the edge and some pegs for levelling. You can make a tamper out of a scaffold plank and you should hire or borrow a poled float. 

Pumped concrete is surprisingly hard work. I just did a 10 metre by 8 metre barn and an adjacent 5 metre by 9 metre slab at my place and we pumped that because most of it was internal. I think we pumped around 20 cubic meters and this was down, tamped and floated by 2pm having started around 9am. My wife and son helped. You will definitely need a mate to help. Will save you a lot to hire a digger, small dumper, put your own stone in reinforce as needed and lay. 

As for size: my home workshop is an old pigeon loft and the main area is about 10m by 3m with a small store room as well at one end. It is hopeless for dealing with sheet goods. Plenty of head height is also good when you are moving big bits of timber around. 

If your electronics area is going to house an oscilloscope or other sensitive kit, then I would without doubt make your shop L shape and seal the electronics room off with a door. 

Check with your electrician what size armoured you need. Many people cut corners here and down spec with 4mm or something. Overspec it. When the day comes that you beed a 16amp bandaw, or P/T, plus extraction, a 3kw fan heater, lots of lighting etc you will be glad you did this. 

Plan in an internet security camera and alarm. I always put in flexible trunking(50mm I think) as it is extra useful when you realise you need another cable. Always leave a draw cord in. And I would stick an ethernet cable through there as well. Plan to have a consumer unit in the shop, with its own trip switches. Costs peanuts, saves a lot of bother and adds flexibility. 

When you are doing the trench for the armoured, stick a plastic water pipe in as well. Tap in or just outside workshop is very handy. 

Work out how many sockets you think you need then double it. Then add a few more. 

Bare concrete for a workshop floor is not good. It's dusty, wears, is hard on the feet. At the very least paint it before you start fit out. You will end up with rubber mats or something if you stand a lot. 

Good luck.


----------



## screwpainting

+1 to all that.


----------



## DomD

AJB Temple":3dy0ogee said:


> My thoughts. Don't be afraid of doing the concrete yourself. It is dead easy. All you need us framing boards around the edge and some pegs for levelling. You can make a tamper out of a scaffold plank and you should hire or borrow a poled float.
> 
> Pumped concrete is surprisingly hard work. I just did a 10 metre by 8 metre barn and an adjacent 5 metre by 9 metre slab at my place and we pumped that because most of it was internal. I think we pumped around 20 cubic meters and this was down, tamped and floated by 2pm having started around 9am. My wife and son helped. You will definitely need a mate to help. Will save you a lot to hire a digger, small dumper, put your own stone in reinforce as needed and lay.


A digger probably won't be possible just due to the accessibility of the site; I can stretch the digging out over a long period however.
The levelling is the thing I am most worried about having never done it before and I may look around for quotes and see what it will cost and if it is worth it. Speed is also limited for this build (I have around 6weeks with lots of time to put in) so it might be better to get the slab laid as a time saver.



AJB Temple":3dy0ogee said:


> As for size: my home workshop is an old pigeon loft and the main area is about 10m by 3m with a small store room as well at one end. It is hopeless for dealing with sheet goods. Plenty of head height is also good when you are moving big bits of timber around.
> 
> If your electronics area is going to house an oscilloscope or other sensitive kit, then I would without doubt make your shop L shape and seal the electronics room off with a door.


Yeah, hopefully I should be able to have a open roof in the main area for moving around larger items. The separate room will definitely be a thing, though currently if you look at my plans you can see it is still a rectangle just with the sub room inside. Maybe an 'L' is a better use of space and I will experiment with a floorplan, though it does add extra complexity for the framing.



AJB Temple":3dy0ogee said:


> Check with your electrician what size armoured you need. Many people cut corners here and down spec with 4mm or something. Overspec it. When the day comes that you beed a 16amp bandaw, or P/T, plus extraction, a 3kw fan heater, lots of lighting etc you will be glad you did this.
> 
> Plan in an internet security camera and alarm. I always put in flexible trunking(50mm I think) as it is extra useful when you realise you need another cable. Always leave a draw cord in. And I would stick an ethernet cable through there as well. Plan to have a consumer unit in the shop, with its own trip switches. Costs peanuts, saves a lot of bother and adds flexibility.


Currently, the max I can get is 230v, 32A as my house main supply is only ~100A; I will talk to him about overspeccing but it is unlikely I will upgrade the main house supply. Hopefully with low power lights and using one tool at a time (with extraction) I should keep it below that. I plan to have a consumer unit.
I am definitely laying an ethernet cable and CCTV is a good idea as I already have a system set up.




AJB Temple":3dy0ogee said:


> When you are doing the trench for the armoured, stick a plastic water pipe in as well. Tap in or just outside workshop is very handy.


I will look into this but the building is above second floor height so the pressure might not be high enough to get it all the way up the hill: it would be nice to be able to make tea up there!



AJB Temple":3dy0ogee said:


> Bare concrete for a workshop floor is not good. It's dusty, wears, is hard on the feet. At the very least paint it before you start fit out. You will end up with rubber mats or something if you stand a lot.


I have seen people using self-levelling compounds - perhaps this is a possibility for the interior, will need to look into that. I suppose you can install the doors and everything first then pour a layer of it on the concrete only in the interior?

Thanks for all your input,
Dom


----------



## MikeG.

A power float finish on concrete is perfectly good for a workshop, and entirely dust-free. It's what I did in mine. The only downside is that it can be a little to smooth, and you sometimes don't get enough grip with your feet if you're planing something putting up some resistance. It can of course be painted.


----------



## TopCat 32

MikeG.":3ss2cepu said:


> A power float finish on concrete is perfectly good for a workshop, and entirely dust-free. It's what I did in mine. The only downside is that it can be a little to smooth, and you sometimes don't get enough grip with your feet if you're planing something putting up some resistance. It can of course be painted.




Make sure when you order concrete you order the right slump, AJB quotes that a finished concrete floor gets dusty, not sure if he means cement dust dusty, and if he does this is because people order a S2 (70 slump) ,and when truck gets there wet it up to about a S3 reducing the strength and causing bleed which leads to the surface dusting up, they seem to do this as a S3 (130 slump) is obviously easier to lay as it is runnier but more expensive as it contains more cement to get it up to the scheduled strength, you will be surprised how many DIY ers come back to us a few days after laying moaning there concrete floor for there Garage/ shed is dusty, when we check 99.9% of the tickets have had water added at customers request, rendering guarantee null and void, experienced and well known groundworking companies do it all the time as well for footings and oversites, but as they are not going to be living in them i guess they dont care 

Good luck


----------



## DomD

TopCat 32":3tbbew2m said:


> MikeG.":3tbbew2m said:
> 
> 
> 
> A power float finish on concrete is perfectly good for a workshop, and entirely dust-free. It's what I did in mine. The only downside is that it can be a little to smooth, and you sometimes don't get enough grip with your feet if you're planing something putting up some resistance. It can of course be painted.
> 
> 
> 
> 
> 
> Make sure when you order concrete you order the right slump, AJB quotes that a finished concrete floor gets dusty, not sure if he means cement dust dusty, and if he does this is because people order a S2 (70 slump) ,and when truck gets there wet it up to about a S3 reducing the strength and causing bleed which leads to the surface dusting up, they seem to do this as a S3 (130 slump) is obviously easier to lay as it is runnier but more expensive as it contains more cement to get it up to the scheduled strength, you will be surprised how many DIY ers come back to us a few days after laying moaning there concrete floor for there Garage/ shed is dusty, when we check 99.9% of the tickets have had water added at customers request, rendering guarantee null and void, experienced and well known groundworking companies do it all the time as well for footings and oversites, but as they are not going to be living in them i guess they dont care
> 
> Good luck
Click to expand...


I will make sure to either use or specify S2; sounds like concrete on its own should be fine then.

I was experimenting with an 'L' layout shown below:





Its very hard to get a sense of scale but in this the electronics room does seem a bit small. It will also complicate the framing but could work better for space, especially in the central area. Does anyone have layouts/images of a shop about this size (16*13 exluding walls) so I could gauge the scale of it when done?

I will need to add furniture etc in CAD to get a true sense of size.

Thanks


----------



## MikeG.

It's not the framing that would complicate, it's the roof.


----------



## DomD

MikeG.":27mu5wf9 said:


> It's not the framing that would complicate, it's the roof.


Yeah, especially the joint between the two gables I imagine. Not really sure if it is worth it as it's also another part to square up etc.

This is my planned floor so far:





Dom


----------



## MikeG.

Don't fall into the trap of assuming depths of hardcore and blinding until you have actually dug a hole. It might be you don't need any hardcore, and if you don't, you'll only need a dusting of sand blinding.


----------



## DomD

MikeG.":38bfcz8i said:


> Don't fall into the trap of assuming depths of hardcore and blinding until you have actually dug a hole. It might be you don't need any hardcore, and if you don't, you'll only need a dusting of sand blinding.


Are there specific conditions under which I should be checking the ground conditions?

I have just got two quotes for 4m^2 of concrete and pumping and both are ~£1000 (incl. VAT). I spoke to a patio/driveway groundwork guy who said he would definitely suggest piers over pumped concrete; I'm going to look into the cost of this but would rather work of a solid concrete floor than a floating one.

Any pumping/concrete companies anyone recommends in the Watford area? 

Thanks


----------



## MikeG.

Do you mean 4 cubic metres? 

I definitely wouldn't pump that. I'd get a friend to help, and barrow it. You'll do 4 cubic metres in a morning that way. Or you could hire a mini dumper.


----------



## DomD

MikeG.":1n05gzuv said:


> Do you mean 4 cubic metres?
> 
> I definitely wouldn't pump that. I'd get a friend to help, and barrow it. You'll do 4 cubic metres in a morning that way. Or you could hire a mini dumper.


It is ~4m^2 but my garden (which I think I posted an image earlier) is on a hill with a retaining wall and steps up to the main area so I would need to construct a ramp and it would be a lot of work up and down. A mini dumper definitely wouldn't get up.
I anticipate it will be enough of a pain to set up the form/subbase so want the concrete delivery to be as smooth with as little mess as possible.
- Dom


----------



## AJB Temple

The problem with pumping is it is uneconomic for small quantities as the pump lorry is a separate machine and another bloke. I would be very surprised if the hill is so steep that you can't get a 1 ton hydraulic dumper up it. That would save a lot of backbreaking work and would be cheap as you could pour from a standard delivery lorry.


----------



## MikeG.

16sq m x 0.15 (depth) = 2.5 cubic metres of concrete. Seriously, just with barrows, that's not much more than an hour or two of work. You'll have to pay a little extra for the mixer waiting on site longer than normal, but it's only going to be pennies compared with hiring a pump. Part load charge (or batch mixed), and you'll have the concrete done for around £300/ £350.


----------



## DomD

AJB Temple":2yysp3t6 said:


> The problem with pumping is it is uneconomic for small quantities as the pump lorry is a separate machine and another bloke. I would be very surprised if the hill is so steep that you can't get a 1 ton hydraulic dumper up it. That would save a lot of backbreaking work and would be cheap as you could pour from a standard delivery lorry.



The problem isn't so much the hill but the retaining wall which would mean I would need to construct a ramp of sorts.



MikeG.":2yysp3t6 said:


> 16sq m x 0.15 (depth) = 2.5 cubic metres of concrete. Seriously, just with barrows, that's not much more than an hour or two of work. You'll have to pay a little extra for the mixer waiting on site longer than normal, but it's only going to be pennies compared with hiring a pump. Part load charge (or batch mixed), and you'll have the concrete done for around £300/ £350.



It's actually gone up to 14*20ft so at 150mm that's 4m^3. I would need to make a ramp for the wheelbarrow and the hill is at least 35° in parts but I guess that could be possible, especially if I get some help. I will look into the cost of no pump: for the companies I quoted the breakdown was half for concrete half for pumping so my guess is ~£500.
Thanks


----------



## TopCat 32

if you go readymix route 4 cube about £90 a cube = £360 you may get a uncarried concrete charge of £37 on the 2m he is not carrying , ( you may get away with this you may not) best check, you will get 30 mins to unload the 4m3 after that it is about £120 a hour waiting time ( theses trucks cost 120 grand each now) so cant be sitting about waiting to discharge, as i tell groundworkers when i am waiting for trucks to return " you bought the concrete not the truck", make sure you have enough labour and wheelbarrows if you dont pump as you can tell it will get dear otherwise,
volumetric will not charge for uncarried concrete and will give you more waiting time, but we keep a check on there prices and last check a equivalent mix to ours was around £160 a m3, not sure how many meters you need to pump but a small trailer pump should cover this, Embassy pumps at caterham would come to you i'm sure, any help i can give please ask
good luck Dom
regards tim


----------



## MikeG.

TopCat 32":3ryynan5 said:


> if you go readymix route 4 cube about £90 a cube = £360 you may get a uncarried concrete charge of £37 on the 2m he is not carrying , ( you may get away with this you may not) best check, you will get 30 mins to unload the 4m3 after that it is about £120 a hour waiting time.........



Paying for half an hour extra on site time (they allow an hour around here, BTW) would on your figures amount to about £440 or £450 total, which compares quite well with £1000 quoted for concrete + pump.


----------



## Junah

Where are you based? might be able to get a working party together to wheel the barrows.


----------



## DomD

MikeG.":2hsnwmu9 said:


> TopCat 32":2hsnwmu9 said:
> 
> 
> 
> if you go readymix route 4 cube about £90 a cube = £360 you may get a uncarried concrete charge of £37 on the 2m he is not carrying , ( you may get away with this you may not) best check, you will get 30 mins to unload the 4m3 after that it is about £120 a hour waiting time.........
> 
> 
> 
> 
> Paying for half an hour extra on site time (they allow an hour around here, BTW) would on your figures amount to about £440 or £450 total, which compares quite well with £1000 quoted for concrete + pump.
Click to expand...


If I was to barrow it what sort of angle would be needed for a slope up the hill? Again, reposting back garden photo from earlier:





You can see in the lower part of the image there is the steep part with the stairs: my guess is this goes up at least three meters from the patio level before it levels out to a more manageable slope.
The other issue would be spillage which would definitely not happen with a pump.

According to this concrete supplier it will take about 25 trips/m^3 or 100 trips total and they recommend 1 person and barrow per m^3. This would mean buying (or hiring) 4 barrows and I doubt this estimate is intended for the distance I would be taking it.

The main reason I have become sceptical about the whole concrete base is that the groundwork contractor I spoke to was adamant that it was not a good idea and recommended a pier foundation: I think preparing the form-work/sub-base would be fine but getting concrete/hardcore up there is the challenge.



Junah":2hsnwmu9 said:


> Where are you based? might be able to get a working party together to wheel the barrows.


I am in the Watford region but should be OK for helpers - benefits of having a large family to enlist. 

Many thanks, Dom


----------



## MikeG.

Piers mean a suspended floor, with a gap underneath, putting your floor level likely 350mm or so above ground level. Not only is that 2 steps up, but it is normally enough to mean the whole scheme falls foul of the height restrictions imposed by permitted developments as you approach a boundary. That's the problem with listening to people who don't have an overview. What on earth does a groundwork contractor know about permitted development rights?

There is an alternative construction method given in my signature, which you might have a look at. The second one. Were you to go along that route I suggest reducing your spans somewhat, otherwise you'll have a sub-wall at mid-span.


----------



## TopCat 32

According to this concrete supplier it will take about 25 trips/m^3 or 100 trips total and they recommend 1 person and barrow per m^3. This would mean buying (or hiring) 4 barrows and I doubt this estimate is intended for the distance I would be taking it.

Dom , that is what we quote as well, you will be surprised how Knackering barrowing 4m is, not wanting to put you off but that it will be best part of 10 ton to move.
as for slope , yes you will get spillage and if wet a right pipper pushing barrows uphill even if you lay scaffold boards down 1st, not sure on the distance from truck discharge point to where you are laying slab, but i would think if you had 4 fit blokes on barrows, and a couple laying/ tamping, you may get it off in a hour to 1.5 hrs, we have had people try these track barrows, which hold about 5 conventional barrowes a time, cost of hire im not sure , but the speed they travel you cold do at least 3 trips with a normal barrow so they are not really cost effective, have you tried contacting a pumping firm for price of pump only . Like Mike says find out from supply companies what they allow you, if you can find one that will give you 1 hour to tip you will save, not sure who he uses , but my guess some of the small independents may be more accommodating, especially if work is quiet, i would go for a slab over pillars all day long

GOOD LUCK


----------



## Echo-Star

Hi Dom

Reading your thread i see you hav'nt set out foundation layout yet, this is easily done with a water lvl "garden hose* 4 x stakes and a string line, start at your highest point and work round, squaring your line as you go 8/10/12, this method works regardless of the lie of the land, I'd go for rectangle shape everytime over the L and a room inside a room is better, bigger is best. Also as you may have to remove 4/5 ton of top soil that has to go somewhere, then maybe use this to gentle the slope if taking the wheelbarrow option.

Rob


----------



## MikeG.

Echo-Star":7wcamh69 said:


> ...... squaring your line as you go 8/10/12..........



?? That's not the pythagorus I know.......  That'd produce a bit of head-scratching on site.


----------



## Echo-Star

is it not a case of scaling up 3/4/5


----------



## MikeG.

Echo-Star":1tc95zu1 said:


> is it not a case of scaling up 3/4/5



No, not even close. 6/8/10 is, though. Or 9/12/15. Another useful pythagorean triple is 5/12/13, or multiples therefof.


----------



## manglitter

This may be useful then....





Sent from my SM-G960F using Tapatalk


----------



## DomD

MikeG.":16v62677 said:


> Piers mean a suspended floor, with a gap underneath, putting your floor level likely 350mm or so above ground level. Not only is that 2 steps up, but it is normally enough to mean the whole scheme falls foul of the height restrictions imposed by permitted developments as you approach a boundary. That's the problem with listening to people who don't have an overview. What on earth does a groundwork contractor know about permitted development rights?
> 
> There is an alternative construction method given in my signature, which you might have a look at. The second one. Were you to go along that route I suggest reducing your spans somewhat, otherwise you'll have a sub-wall at mid-span.



Height isn't so much an issue as I am 2m from boundaries. Is there any threads with images of people who have tried your alternative design? If necessary I could reduce the span to 4m. 
As I said I definitely hope to do a slab.

Unfortunately I can do very little on this until early June (other than planning). Is there an ideal time to check ground conditions to see how much sub base I would be looking at?

Thanks


----------



## DomD

After getting a quotes for the concrete slab and looking into the suspended option I think I will just do the slab myself with 150mm sub-base (or less hopefully) the sand and DPM then 150mm of concrete. 

Any good resources on how to properly construct the wood form? I also want to keep the slab in line with my fence and another building so I suppose I will just measure at each end the length to the fence and keep it constant.

Is a perimeter of gravel around worth doing?
Thanks

Edit: Also looking at a mini dumper I think I may be able to take it up the stairs to the upper garden? If so this would help hugely and I could probably use it for both hardcore and concrete. They are also very affordable. Otherwise, is there a good way to make a ramp for a dumper? Scaffold boards layed over the stairs?
With a 0.5t mini tracked dumper it would be 20 trips for the concrete. My guess would be at least 10m a trip so up to 4h on site.


----------



## DomD

After a discussion with Mike this is the base structure I think I am going to go for:




EDIT: This is wrong, sub base should be under the edges, not in the middle.
There will also be A142 mesh throughout the top 150mm of the slab and the thickened edges will be slightly thinner.

Initially I was just going to do the 150mm with slightly thickened edges but the subsoil at the front of the plot extends down to 500mm below the surface as shown below:




So instead I am going for a 'raft-style' with subsoil and a layer of hardcore (with sand blinding) between the two edges. At points the thickened edges will be 500mm in depth.

I was concerned about 'clay heave' but luckily the soil in my area seems to be mainly silt/sand with very little clay; if there was clay I would have needed to add a void former which are quite expensive.

I think plugs in the floor would be very practical (if they can be kept flush/below the surface so I can still assemble stuff). I've seen people putting ducting through or below the concrete but am unsure of the best way to do this. Are there any specific products that would be suited to a concrete floor in a workshop?

Thanks, Dom


----------



## DomD

For the thickened edges I plan to have 4 16mm diameter bars running down each similar to shown below (but only one covering of mesh).





I'm guessing the link members only need to be regular enough to hold the other bars in place.
At the corners should the steel be bent round or is it fine to just cut it to length and tie to the other bars at right angles.
Also, would reducing the slab thickness to 100mm have much of an impact on strength?
Thanks


----------



## MikeG.

You're getting into an engineered solution here Dom, unnecessarily. The thickened edges I've suggested would be bearing on decent ground, and are therefore just a solid lump of something for the slab to sit on. They won't need steel in them.......but the slab will, as we've discussed. Think of the thickened edges as sleeper walls. The floor we were discussing isn't a raft (in which the whole thing floats around on a soft substrate). It is a suspended slab, bearing on the 4 outer edges.

You're on your own for a week.


----------



## DomD

MikeG.":3tgxj7dn said:


> You're getting into an engineered solution here Dom, unnecessarily. The thickened edges I've suggested would be bearing on decent ground, and are therefore just a solid lump of something for the slab to sit on. They won't need steel in them.......but the slab will, as we've discussed. Think of the thickened edges as sleeper walls. The floor we were discussing isn't a raft (in which the whole thing floats around on a soft substrate). It is a suspended slab, bearing on the 4 outer edges.
> 
> You're on your own for a week.


Right, I will leave them empty then. I guess most of the stuff online is for building regs brick buildings.


----------



## DomD

I am hopefully going to get started on diggng the ground etc. next week. Is storing soil in bulk bags effective or should I be looking at another storage method?
Also a couple questions in relation to tools. I have seen US framers using 'speed squares' and was wondering if anyone had one and could comment on its usefulness; I would probably get a metric one if so.
Also there is currently a 10% off code on eBay and I am thinking about getting a DWS774 because I do not trust my old evolution saw to get me through this project. If anyone has any comments on that particular model then I would love to hear your thoughts.
Dom


----------



## RobinBHM

Im in the final stages of building a garden studio around 5m x 4m. 

I havent used a framing square to set out or check anything. Personally I prefer triangulation for setting out -its far more accurate.

I use an app called right angled triangle solver -it works on android. Its only basic trig, but saves doing any calcs, just enter the figures.


----------



## DomD

Today I put together some saw horses to get my mitre saw off the ground. I used this design and probably ended up taking longer than it could have due to the chiseled out sections.










I ended up getting a bosch saw in the sale - had to get sliding due to wide joists







RobinBHM":nea0wolp said:


> I havent used a framing square to set out or check anything. Personally I prefer triangulation for setting out -its far more accurate.



I did actually end up getting one - only for rough setting out before using triangles and diagonals. I will probably be setting out with batter boards tommorow.
Any ideas what sort of length is most suitable for a temporary saw station on the saw horses? I suppose enough to set up a stop block to cut studs, however it probably won't be long enough for joists.

Thanks for all the advice so far; Dom.


----------



## MikeG.

I have a set of taller saw horses for bench-type operations, such as using a chop saw. I put 3 or 4 scaffold boards across them and I then have a perfectly serviceable workstation. The smaller saw horses, as per the ones in the photos above, are used for hand sawing and so on (and for green oak framing). They don't get a lot of use when doing stud work.

You don't need a square for framing. In fact, they're a potential nuisance. You cut your plates (top and bottom members) accurately, clamp them together and mark up the stud positions on both at the same time. Once the studs are nailed in, squareness is achieved by correcting the diagonals until they are the same length.........and by nailing on your sheathing boards, which are in effect large accurate squares. A roofing square is an invaluable piece of site and workshop equipment, but don't use it for softwood framing.


----------



## DomD

MikeG.":1d3t75p4 said:


> I have a set of taller saw horses for bench-type operations, such as using a chop saw. I put 3 or 4 scaffold boards across them and I then have a perfectly serviceable workstation. The smaller saw horses, as per the ones in the photos above, are used for hand sawing and so on (and for green oak framing). They don't get a lot of use when doing stud work.
> 
> You don't need a square for framing. In fact, they're a potential nuisance. You cut your plates (top and bottom members) accurately, clamp them together and mark up the stud positions on both at the same time. Once the studs are nailed in, squareness is achieved by correcting the diagonals until they are the same length.........and by nailing on your sheathing boards, which are in effect large accurate squares. A roofing square is an invaluable piece of site and workshop equipment, but don't use it for softwood framing.


I should have realised these were a little low... still will be useful no doubt. I will look into getting some second hand scaffold boards.

Sent from my MI 8 using Tapatalk


----------



## DomD

I layed out the site yesterday (added string lines after this picture):





The slope on the ground seems exaggerated now that I have taken a level to it. There is a ~300mm fall from the top of the site to the bottom which means ~4m^3 earth removal just for flattening and possibly another 4m^3 after for digging out the concrete pour area. I can't see this as being possible without a mini-digger (which I would be uncomfortable using, but could hire someone to do it) and even then many bulk bags would be filled with the excavated soil.

I'm not sure if there is any way of estimating if this would be doable by hand and in what timescale; I would much rather do a slab base than piers as previously discussed but I suppose piers would mean little digging. My only other thought would be to do an 'on grade' slab or have the slab mostly above ground with only the deep thickened edges below.

I would appreciate any thoughts,
Dom


----------



## DomD

I have layed out my site on CAD and think I have found a way to reduce amount needing dug while sticking to the previous design. Instead of flattening then digging the foundations, I was wondering if I could use the dig in to the slope as the back of 'shuttering' for the concrete: at the back concrete would be fully under surface level apart from 50mm above surface, at the front the concrete would be poking far above the surface (~250mm) but I could later use excavated earth to bring the surface level up so it is only 50mm. This is quite hard to explain so I made some slides of the steps I plan to follow.

First would be digging into the slope; thickened edges shown.





Then I would be adding hardcore and sand (need this in thickened edges too, forgot in CAD).





Next would be adding shuttering, you can see it would be almost completely below the surface at the back, using earth along with posts for support. I have read shuttering is not needed against soil in the thickened edge 'trenches', is that correct?





Then the concrete would be poured.





Then I would remove the shuttering.





Maybe this way of doing it seemed obvious but it only came to me today; this should make it a managable job with a mattock and a few friends. Just wanted to check here first to ensure this is not a mistake!
Dom


----------



## DomD

About to make first order of materials for base.
I confused myself over the previous base diagram. As far as I am aware this redrawn one, with the load bearing thickened edges bedded on hardcore, not no hardcore under the middle, is correct. This is good news as it means only around a bulk bag of sharp sand and one bulk bag of mot 1.




The forms are out of C24 22x150mm with 50mm C24 pegs every 2ft. I have read that should be sufficiently strong, but don't want the form to warp too much. The thickened edges will be formed partially by a timber length and partially by soil (as shown).

This is my current shopping list for the base. Brickwork items not included.







Code:


1) Empty bulk bags for excess soil.
2) 22x150 timber for forms
3) Levels for levelling formwork (replacing my battered ones, have added a set, heard stabila are reliable)
4) Mesh for reinforcement
5) DPM 1200g, not sure how I should be taping this together
6) Sub base
7) Coarse sharp sand for blinding
8) Wheelbarrow for moving aggregates
9) Timber to make pegs - I can only do up to 47 degrees on the point but this seems to drive fine
10) Nails for connecting forms to pegs

Really hope I have not missed anything as want to get this base down as soon as I can.
Dom


----------



## MikeG.

I always screw formwork, because it makes de-mounting it much easier afterwards. Also nailing a fairly flimsy and floppy structure induces lots of movement, wobbling pegs around in the ground, for instance. Further, there is lots of adjusting to get the top level, and that can involve putting in and taking out fixings 2 or 3 times, which is much easier with screws. Make sure you screw from the outside!!


----------



## DomD

MikeG.":2rhmwlmj said:


> I always screw formwork, because it makes de-mounting it much easier afterwards. Also nailing a fairly flimsy and floppy structure induces lots of movement, wobbling pegs around in the ground, for instance. Further, there is lots of adjusting to get the top level, and that can involve putting in and taking out fixings 2 or 3 times, which is much easier with screws. Make sure you screw from the outside!!


I swapped over to screws... probably worth getting an impact driver now then. I also got lumber twice the thickness for the formwork as I was worrying about flex.

Sent from my MI 8 using Tapatalk


----------



## DomD

I have now ordered all of that, due next Tuesday (hopefully to have concrete done in next few weeks).

I am struggling to square the site properly with the string lines. The angles are fairly square but not perfect: I assume this is fine as the string lines are simply for excavation purposes? Once the site is flattened I will construct the formwork, square and brace it before digging out the deep trenches.

Dom


----------



## DomD

The delivery of the former items should arrive tommorow; I am now looking at items for the brickwork. The dwarf wall will be (no more than) 68ft long all around (doorway will reduce this) so all calculations are done to this. This is my shopping list so far:







Code:


1) 300 heather bricks - seem closest to mine and are frogged, is that what I should be going for?
2) 100mm thermalite blocks, will cut down to get 50 total.
3) Strapping to screw in below blocks.
4) A bulk bag of sand for mortar.
5) 6x 25kg bags of OPC (should I be using white?)
6) 3 bags of 'hydrated lime', again not sure if this is neccesary of if I should just be using a plasticiser.
7) a board to screed the concrete


I will soon finalise door placement etc. I am using Mike's reccomendation of '6:1:1/2 sand: white cement: lime' from thewoodhaven2, not sure if white is advisable here as the brickwork I am trying to imitate does not have very white joints.


----------



## DomD

Lots done in past few days.
Site flattened to level and ditches dug:




You can see at the back where the site goes into pretty solid chalk rock:





I also cut down a buch of pegs for the formwork; these are only 47 degreed but drive ok:





Other than the base the hardest work was moving two bulk bags of material up my garden, must have spend at least 6h going up and down.


----------



## DomD

Anyone got any ideas how to fill this gap in my formwork? Was initially going to do compacted earth but not sure the strength to hold back the concrete will be there, even when compacted.





Also I was wondering if, as the walls of the trenches are just earth, I should extend the dpm upwards to ensure the water does not get soaked up by the earth too quickly when drying? I am currently planning to go with mike's design and just take the dpm to the bottom edges of the trenches.

Thanks


----------



## will1983

Don't worry about the gap in the formwork and don't bother trying to compact muck into it, it won't work.

What we usually do in this case (I'm a Civil Engineer by trade) is fill the trench to the level of the bottom of the formwork. Start at your problem area as this gives the concrete there a bit of time to stiffen up. Don't worry about it spreading out under your forms, just get it in and compacted nicely up to the lower edge of the forms.

Now throw a few shovelfuls of muck against the back of the formwork on top of the lower concrete and then top up to your finished level. Poker through the layers to ensure they are knitted together properly.

If you do this it'll give you the nice square, vertical shape to the bit of the foundation that will be visible once the building is complete.

Don't forget to use a poker vibrator to compact your concrete properly and once its all filled up and screeded off with a tamp go round the edge of your slab with an arris trowel, this prevents that rough flaky corner you usually get with a squared off edge.

The project looks to be progressing nicely, I don't envy you having to dig through that rocky chalk mind!


----------



## DomD

will1983":1oppq4m9 said:


> Don't worry about the gap in the formwork and don't bother trying to compact muck into it, it won't work.
> 
> What we usually do in this case (I'm a Civil Engineer by trade) is fill the trench to the level of the bottom of the formwork. Start at your problem area as this gives the concrete there a bit of time to stiffen up. Don't worry about it spreading out under your forms, just get it in and compacted nicely up to the lower edge of the forms.
> 
> Now throw a few shovelfuls of muck against the back of the formwork on top of the lower concrete and then top up to your finished level. Poker through the layers to ensure they are knitted together properly.
> 
> If you do this it'll give you the nice square, vertical shape to the bit of the foundation that will be visible once the building is complete.
> 
> Don't forget to use a poker vibrator to compact your concrete properly and once its all filled up and screeded off with a tamp go round the edge of your slab with an arris trowel, this prevents that rough flaky corner you usually get with a squared off edge.
> 
> The project looks to be progressing nicely, I don't envy you having to dig through that rocky chalk mind!



So if I understand correctly you are suggesting filling up the ditch behind the form up to the bottom of the form level and then adding back some topsoil and continuing to fill to the top of the form, leaving only the flat edge visible?

If so that will work well for some of my sides but the pictured side, the gap below the form continues to a slope, so pouring the concrete without it filled would mean it would start running down.

I was more wondering if forming a slope up to the form from behind (with topsoil), compacted with a sledgehammer, would be sufficient to hold back the concrete under the formwork.

Hope that makes sense, 
Dom


----------



## will1983

I understand what you mean, the ground level is below the bottom of the form so you're concerned it'll overflow.

Don't worry about it, unless its more than about 100-150mm and your concrete is particularly sloppy it wont be an issue. If i remember rightly you're going to order an S2 slump in which case the concrete should have enough body to prevent it slumping down. Just be cautious in your use of the poker in that area. If it is wanting to run just leave some to one side for a while to let it stiffen up a bit before placing.

Working with concrete may appear a bit daunting at first but it's pretty easy in practice. You'll soon get a feel for it.


----------



## will1983

Also concrete has a density of 2.4T/m3 so don't underestimate its capacity for knocking over formwork or as you suggested, heaped muck.

On the positive side though it's not like water, it is a cohesive material so doesn't want to move unless it is agitated by a poker.


----------



## DomD

Ok thanks for that advice; I am aware of how heavy concrete can be after watching some formwork bending severely on youtube - I will try to avoid that with pegs every 2ft driven in with a sledgehammer.

I ideally want to use S2, but am I correct in thinking they will use a more dilute 'pump mix' if pumping? If so I suppose that would increase the risk of concrete flowing through gaps.
Do you think a vibrating poker is necessary considering only the front trench of my foundation reaches ~600mm?

Concrete pouring is certainly the bit I'm most concerned about in this build!


----------



## DomD

I sort of fixed the problem by lowering the formwork - this will mean the slab is ~100mm thick in the middle. I will then be able to use the method of filling the trenches, covering concrete at sides with earth and filling to the top.


----------



## DomD

Three sides now squared and pegged down. I have 50mm posts every two feet which I suppose should be enough (all go at least 300mm below ground). 
As for level - it is as close as I can get but still not perfect (within two center lines of bubble level but not perfectly centered at all points). I think this could be down to slightly bent timber and the cleat I had to make on the long side doesn't help. 
There is still loose sandy soil on the surface of the filled area - will this be problematic? Compacting with a sledgehammer doesn't help.
Thanks


----------



## DomD

Form fully layed out now, still need to add a few more pegs. Then it will be hardcore, sand, dpm and steel mesh.

The diagonals are within 1/2in, is that an acceptable tolerance?


----------



## Woody2Shoes

DomD":29e0l8dz said:


> Ok thanks for that advice; I am aware of how heavy concrete can be after watching some formwork bending severely on youtube - I will try to avoid that with pegs every 2ft driven in with a sledgehammer.
> 
> I ideally want to use S2, but am I correct in thinking they will use a more dilute 'pump mix' if pumping? If so I suppose that would increase the risk of concrete flowing through gaps.
> Do you think a vibrating poker is necessary considering only the front trench of my foundation reaches ~600mm?
> 
> Concrete pouring is certainly the bit I'm most concerned about in this build!



Hi - if pumping, the mix will be slightly wetter than it might be otherwise. If your formwork is square to the the nearest 1/2 inch that's probably just fine. If it were me doing it, I'd put down a sheet of DPM across the whole thing - wrapping the edge over your formwork and fixing it along the edge with battens. Two reasons for this:
1) the concrete will cure better, as the soil underneath won't suck out any moisture from it.
2) you'll save a bit of concrete (at £100+VAT or more per metre) from leaking out under the forms under the outer corners (I take the previous poster's word for the fact that if you follow his technique you won't 'lose' much but...especially if it's a 'pump mix').
Spending £20 on some plastic sheet and half an hour fixing it in place might save it's worth in concrete (there's a certain amount of waste with a pump anyway) and yield a better-cured slab.
Cheers, W2S

PS I'd definitely recommend a poker (a small elctric one should be fine) - I would say this is another factor in favour of the DPM sheet suggestion, as the poker does mobilise the water and fines in preference to the heavier bits.


----------



## DomD

Woody2Shoes":26r2l7rl said:


> Hi - if pumping, the mix will be slightly wetter than it might be otherwise. If your formwork is square to the the nearest 1/2 inch that's probably just fine. If it were me doing it, I'd put down a sheet of DPM across the whole thing - wrapping the edge over your formwork and fixing it along the edge with battens. Two reasons for this:
> 1) the concrete will cure better, as the soil underneath won't suck out any moisture from it.
> 2) you'll save a bit of concrete (at £100+VAT or more per metre) from leaking out under the forms under the outer corners (I take the previous poster's word for the fact that if you follow his technique you won't 'lose' much but...especially if it's a 'pump mix').
> Spending £20 on some plastic sheet and half an hour fixing it in place might save it's worth in concrete (there's a certain amount of waste with a pump anyway) and yield a better-cured slab.
> Cheers, W2S
> 
> PS I'd definitely recommend a poker (a small elctric one should be fine) - I would say this is another factor in favour of the DPM sheet suggestion, as the poker does mobilise the water and fines in preference to the heavier bits.



I'm putting down dpm anyway - wrapping up the edge and over the form shouldn't be an issue as I have spare: I'm guessing I would then cut it back to ground level so the slab can still dry naturally? 

By fixing with battens do you mean using pieces of wood and screws to 'clamp' the dpm in place? I can always fill some earth in behind parts of the dpm below the form that are holding concrete to help with support.

Cheers


----------



## MikeG.

Dom, don't forget to have somewhere for spare concrete to go. It is inevitable that there will be a bit left over at the end of the pour, so maybe prepare a sub-base for a path, patio, a bit of hardstanding...whatever. Also, trim your 2x2 support posts down to below the level of the formwork, because they'll interfere with your tamping.


----------



## DomD

MikeG.":1yji1n33 said:


> Dom, don't forget to have somewhere for spare concrete to go. It is inevitable that there will be a bit left over at the end of the pour, so maybe prepare a sub-base for a path, patio, a bit of hardstanding...whatever. Also, trim your 2x2 support posts down to below the level of the formwork, because they'll interfere with your tamping.



Will be trimming down the posts; just going to use a 2x4 for the screed board so hopefully they send some that are not too warped.

As for extra if I am correct I can order volumetric concrete with an estimate of volume and they will only pump as much as I need? This seems to be what it suggests online and I'd much rather do no more digging.

Dom


----------



## DomD

I now have a quote for £95/m^3 of C25 (+vat) volumetric (mixed at site concrete). The pump is then £350 (+vat). 
With ~6m^3 of concrete that's quite expensive but I would rather do the base correctly.
Fibres are an extra £10/m^3, worth it to prevent cracking?
Dom


----------



## Woody2Shoes

DomD":621oo16g said:


> MikeG.":621oo16g said:
> 
> 
> 
> Dom, don't forget to have somewhere for spare concrete to go. It is inevitable that there will be a bit left over at the end of the pour, so maybe prepare a sub-base for a path, patio, a bit of hardstanding...whatever. Also, trim your 2x2 support posts down to below the level of the formwork, because they'll interfere with your tamping.
> 
> 
> 
> 
> Will be trimming down the posts; just going to use a 2x4 for the screed board so hopefully they send some that are not too warped.
> 
> As for extra if I am correct I can order volumetric concrete with an estimate of volume and they will only pump as much as I need? This seems to be what it suggests online and I'd much rather do no more digging.
> 
> Dom
Click to expand...


The waste comes from the fact that - depending on the size and design of the pump - there could be something in the region of a m3 "in the works" which has already been delivered from the mixer (and you will thus buy this, along with all the other concrete that came out of the mixer too) but is somewhere between the input hopper and business end of the output pipe. This needs to be dumped/washed out of the pump - what I do is build a small "paddling pool" with scaff boards and dpm to allow the pump operator to clean out into that (this will need space off road). You'd be well advised to have a few spare bits of DPM around anyway to catch any small spills between mixer and pump (or at least make them easier to tidy up).
Cheers, W2S


----------



## Woody2Shoes

DomD":3t15n99g said:


> Woody2Shoes":3t15n99g said:
> 
> 
> 
> Hi - if pumping, the mix will be slightly wetter than it might be otherwise. If your formwork is square to the the nearest 1/2 inch that's probably just fine. If it were me doing it, I'd put down a sheet of DPM across the whole thing - wrapping the edge over your formwork and fixing it along the edge with battens. Two reasons for this:
> 1) the concrete will cure better, as the soil underneath won't suck out any moisture from it.
> 2) you'll save a bit of concrete (at £100+VAT or more per metre) from leaking out under the forms under the outer corners (I take the previous poster's word for the fact that if you follow his technique you won't 'lose' much but...especially if it's a 'pump mix').
> Spending £20 on some plastic sheet and half an hour fixing it in place might save it's worth in concrete (there's a certain amount of waste with a pump anyway) and yield a better-cured slab.
> Cheers, W2S
> 
> PS I'd definitely recommend a poker (a small elctric one should be fine) - I would say this is another factor in favour of the DPM sheet suggestion, as the poker does mobilise the water and fines in preference to the heavier bits.
> 
> 
> 
> 
> I'm putting down dpm anyway - wrapping up the edge and over the form shouldn't be an issue as I have spare: I'm guessing I would then cut it back to ground level so the slab can still dry naturally?
> 
> By fixing with battens do you mean using pieces of wood and screws to 'clamp' the dpm in place? I can always fill some earth in behind parts of the dpm below the form that are holding concrete to help with support.
> 
> Cheers
Click to expand...


Concrete ideally needs to be kept covered so it doesn't dry out too quickly - for the first two or three weeks anyway - water is important to the curing process.

Yes, the battens would be horizontal along the outside of the top of the form "clamp" the edge of the DPM.


----------



## Woody2Shoes

DomD":2eh0ob8v said:


> I now have a quote for £95/m^3 of C25 (+vat) volumetric (mixed at site concrete). The pump is then £350 (+vat).
> With ~6m^3 of concrete that's quite expensive but I would rather do the base correctly.
> Fibres are an extra £10/m^3, worth it to prevent cracking?
> Dom



I like fibres - I don't know why they don't come as standard! But you would no doubt be fine without them (although if it were screed, I'd definitely say they're worth it).


----------



## DomD

Woody2Shoes":z52zi7rg said:


> DomD":z52zi7rg said:
> 
> 
> 
> 
> 
> Woody2Shoes":z52zi7rg said:
> 
> 
> 
> Hi - if pumping, the mix will be slightly wetter than it might be otherwise. If your formwork is square to the the nearest 1/2 inch that's probably just fine. If it were me doing it, I'd put down a sheet of DPM across the whole thing - wrapping the edge over your formwork and fixing it along the edge with battens. Two reasons for this:
> 1) the concrete will cure better, as the soil underneath won't suck out any moisture from it.
> 2) you'll save a bit of concrete (at £100+VAT or more per metre) from leaking out under the forms under the outer corners (I take the previous poster's word for the fact that if you follow his technique you won't 'lose' much but...especially if it's a 'pump mix').
> Spending £20 on some plastic sheet and half an hour fixing it in place might save it's worth in concrete (there's a certain amount of waste with a pump anyway) and yield a better-cured slab.
> Cheers, W2S
> 
> PS I'd definitely recommend a poker (a small elctric one should be fine) - I would say this is another factor in favour of the DPM sheet suggestion, as the poker does mobilise the water and fines in preference to the heavier bits.
> 
> 
> 
> 
> I'm putting down dpm anyway - wrapping up the edge and over the form shouldn't be an issue as I have spare: I'm guessing I would then cut it back to ground level so the slab can still dry naturally?
> 
> By fixing with battens do you mean using pieces of wood and screws to 'clamp' the dpm in place? I can always fill some earth in behind parts of the dpm below the form that are holding concrete to help with support.
> 
> Cheers
> 
> Click to expand...
> 
> 
> Concrete ideally needs to be kept covered so it doesn't dry out too quickly - for the first two or three weeks anyway - water is important to the curing process.
> 
> Yes, the battens would be horizontal along the outside of the top of the form "clamp" the edge of the DPM.
Click to expand...

Ideally I was going to start bricklaying 2days after the pour - I know it doesn't reach full strength till a month but I have read bricks after a couple days are fine and a wooden structure after a week is fine too, but heavy machinery should be kept off it?
I can always cover the site overnight and when not in use with a tarpaulin.


----------



## TopCat 32

i am a batcher for 1 of the major ready mix concrete suppliers, you will be lucky to get a pump operator to pump a S2 (70 slump) mix, pump mixes are S3 (130 slump), as for fibers i take it by fibers you mean the glass fiber type, these only help with surface cracking from shrinkage they have no structural benefit the larger Duros or Nova fibers are for structural work, as i have not followed whole post i guess you are laying a course or 2 of bricks on this footing? in which case save your money and dont add fibers i produce in the region of 30k M3 a year and have never put fibers in footings, if you are worried about the structural integrity order a stronger mix, but as most 2 story houses are built on C10 mixes in our area (clay) i wouldn't think you would need anything to strong, but to pump concrete it is suggested a minimum cement content of 280kg pr M3.
, hope this helps

Regards Tim

PS shouldn't be any over as a good pump operator should gauge when you are getting near the end of your pour and how much he has in his line and run pump empty to top up footing


----------



## Woody2Shoes

TopCat 32":18lueg2b said:


> PS shouldn't be any over as a good pump operator should gauge when you are getting near the end of your pour and how much he has in his line and run pump empty to top up footing



I think this does depend on the type/design of pump - and the amount of additional pipework attached. My local supplier asks for - and uses - a "washout box" 2mx2mX200mm which usually gets about two-thirds-full of surplus concrete material and washing water from the pump. I also need to have on hand extra bags of dust (one per 20m of pipe) for grout to prime the pump. Cheers, W2S

PS I like the idea of fibres in reinforced concrete to potentially increase the life of the steel (because cracks happen and fibres are a cheapish way to reduce them - I quite agree they'd be pointless in this case, although very useful for pretty much any screed).


----------



## DomD

Woody2Shoes":31n6jqdg said:


> TopCat 32":31n6jqdg said:
> 
> 
> 
> PS shouldn't be any over as a good pump operator should gauge when you are getting near the end of your pour and how much he has in his line and run pump empty to top up footing
> 
> 
> 
> 
> I think this does depend on the type/design of pump - and the amount of additional pipework attached. My local supplier asks for - and uses - a "washout box" 2mx2mX200mm which usually gets about two-thirds-full of surplus concrete material and washing water from the pump. I also need to have on hand extra bags of dust (one per 20m of pipe) for grout to prime the pump. Cheers
Click to expand...


Is a suitable 'washout box' just a ditch in the ground? The concrete supplier has said it will be 2-3 barrels from the augers and perhaps a little extra from too much concrete getting blown through.

I am also looking into hiring some tools for preparation and the concrete pour:
- Concrete poker I can get for £32(+vat)
- Power float I can get for £80(+vat)
- 'Easy float' for £36(+vat)

I am wondering if you need to first use a boom float then a power float or I could just hire the latter.
Thanks


----------



## adidat

I had this bad boy to do my base 17m boom!!! liebherr know how to make good gear!












Adidat


----------



## adidat

i might be putting the cat amongst the pigeons here but i had my almost 90 sqm base 120mm thick base bored in three sections on top of 200mm compacted hardcore. without a scrap of iron, fibres or membrane and two years on its still fine.... I did put my grandad (a 92 year old @rse kicking ww2 RAF vet engineer) and my beloved labrador's ashes in the concerete so that probably made a big difference!! :lol: :lol: :lol: 

My only regret was not having it professionally power floated, but having all the work done including garden clearing for about 4k I was fairly strapped for cash....

adidat


----------



## adidat

And i didn't require the washout area as the driver just dumped it in the area for the next weeks pour. this proved problematic when we ran out of gear on the last pour and caused 2 very panicked trips to bradfords for a dumpy bag of ballast and cement. Which was hand mixed on site, all on a very hot july day

But all worth while in the end

Adidat


----------



## MikeG.

DomD":17ktaudm said:


> .........I am also looking into hiring some tools for preparation and the concrete pour:
> - Concrete poker I can get for £32(+vat)
> - Power float I can get for £80(+vat)
> - 'Easy float' for £36(+vat).......



Poker......yes. You'll use it for less than 5 minutes, but it's worthwhile.

Power float......that's what I did for my workshop, and if I were being critical, I would say it possibly produces too smooth a finish. When pushing hard with a plane my feet can slip a little unless I have the right shoes on. If I had my time over again, I might have hand-floated it. Also, you have to wait until the concrete is precisely right, and that might mean 2 o'clock in the morning

Easy float.......too much skill involved unless you have done it before.

With your small base I would hand float. You work with a steel trowel, reaching in from the edges as far as you can, then carefully laying a board on the top of the concrete and kneeling on it to reach the middle of the slab. If you have a plastic float in your non-working hand you can use it to hold/ balance yourself as you go, resting on the concrete. Again, the critical thing is timing. Too early and you'll leave indentations in the surface of the concrete. Too late and you won't get it smooth. Just keep checking the concrete every half an hour to see how it is setting. Try the trowel..........if it raises water the concrete still isn't ready.

You do the floating after you have tamped the surface with a long straight-edge. You'll need wellies on, and you stand in the wet concrete, working backwards. Use both a tamping action (up and down) and a cutting action, where you go back and forth across the surface, cutting away the high points. Fill in low points from behind you as you go. As a beginner you'll need a straight piece of wood which is longer than the width of your base.

Pour it, tamp it, walk away.......clean up all your tools and boots at this point, using lots of water and a stiff brush. Go back regularly to check on the rate of setting, and judge when to start troweling up the surface. The following day, carefully spray the whole surface with water, and keep it constantly wet for a day or two. If you then start bricklaying, keep off the concrete. Work from the outside. Stack your bricks on the ground outside the concrete. Otherwise you'll likely generate powdering of the surface. 

Now...get on with it!!


----------



## DomD

MikeG.":1go49b9o said:


> Now...get on with it!!



I want to get started but currently on holiday! Hopefully pour will happen next week and framing will begin the week after. I will buy some 2x6s to act as a tamping board and for hand floating.

Are cheap concrete/bricklaying tools worth it for this use case? I can't imagine I will be doing any more in a long time and don't know if I can justify £30+ for a trowel.

Also any recommendations for 'anti-alkali gloves"? Are washing up gloves acceptable?


----------



## Woody2Shoes

DomD":1rmellbq said:


> Woody2Shoes":1rmellbq said:
> 
> 
> 
> 
> 
> TopCat 32":1rmellbq said:
> 
> 
> 
> PS shouldn't be any over as a good pump operator should gauge when you are getting near the end of your pour and how much he has in his line and run pump empty to top up footing
> 
> 
> 
> 
> I think this does depend on the type/design of pump - and the amount of additional pipework attached. My local supplier asks for - and uses - a "washout box" 2mx2mX200mm which usually gets about two-thirds-full of surplus concrete material and washing water from the pump. I also need to have on hand extra bags of dust (one per 20m of pipe) for grout to prime the pump. Cheers
> 
> Click to expand...
> 
> 
> Is a suitable 'washout box' just a ditch in the ground? The concrete supplier has said it will be 2-3 barrels from the augers and perhaps a little extra from too much concrete getting blown through.
> 
> I am also looking into hiring some tools for preparation and the concrete pour:
> - Concrete poker I can get for £32(+vat)
> - Power float I can get for £80(+vat)
> - 'Easy float' for £36(+vat)
> 
> I am wondering if you need to first use a boom float then a power float or I could just hire the latter.
> Thanks
Click to expand...


I think Mike and others have already answered most of these these. Of course you can washout into a (your) ditch - but the liquid isn't great for tree roots etc. and the solids can be reused elsewhere, so it's your choice really.

I like gloves that are fully nitrile dipped and fabric lined e.g https://www.safetygloves.co.uk/22173.html and eye protection is well worth it too while on the subject of PPE. You could use kitchen gloves but they're very sweaty!

Cheers, W2S


----------



## Woody2Shoes

adidat":1fc7dgs2 said:


> ...and two years on its still fine....
> 
> adidat



Two years? Early days! I don't know what your subsoil's like in zummerzet (probably quite stony?). I guess it will last much longer without steel in it anyway!


----------



## DomD

I will get some of those gloves. I think I may dig a ditch and line it with dpm for the washout box.

Most earth has now been removed from ditches so I will begin to fill with mot 1 then sand.
















Concrete delivery is booked for Wednesday so hopefully I can begin bricklaying on Friday!
Dom


----------



## DomD

Mot 1 down and compacted (with sledgehammer), sand blinding down.


----------



## BigMonka

I can’t add any technical sort of help, but just wanted to say that I love watching threads like this develop so thanks for going to effort of posting it all


----------



## DomD

Woody2Shoes":3kl3qe7n said:


> If it were me doing it, I'd put down a sheet of DPM across the whole thing - wrapping the edge over your formwork and fixing it along the edge with battens. Two reasons for this:
> 1) the concrete will cure better, as the soil underneath won't suck out any moisture from it.
> 2) you'll save a bit of concrete (at £100+VAT or more per metre) from leaking out under the forms under the outer corners (I take the previous poster's word for the fact that if you follow his technique you won't 'lose' much but...especially if it's a 'pump mix').
> Spending £20 on some plastic sheet and half an hour fixing it in place might save it's worth in concrete (there's a certain amount of waste with a pump anyway) and yield a better-cured slab.
> Cheers, W2S



Forgot to ask this - will this not lead to water becoming trapped between the bottom of the concrete and the dpm?


----------



## J-G

Am I missing something? 

You said on 12th July "Will be trimming down the posts;" but I see that many of the posts are still higher than the form-work so will interfere with the tamping once the concrete has been pumped.


----------



## DomD

J-G":14v6xzwm said:


> Am I missing something?
> 
> You said on 12th July "Will be trimming down the posts;" but I see that many of the posts are still higher than the form-work so will interfere with the tamping once the concrete has been pumped.


Cutting now (only front and back)!


----------



## Woody2Shoes

DomD":108z2seg said:


> Woody2Shoes":108z2seg said:
> 
> 
> 
> If it were me doing it, I'd put down a sheet of DPM across the whole thing - wrapping the edge over your formwork and fixing it along the edge with battens. Two reasons for this:
> 1) the concrete will cure better, as the soil underneath won't suck out any moisture from it.
> 2) you'll save a bit of concrete (at £100+VAT or more per metre) from leaking out under the forms under the outer corners (I take the previous poster's word for the fact that if you follow his technique you won't 'lose' much but...especially if it's a 'pump mix').
> Spending £20 on some plastic sheet and half an hour fixing it in place might save it's worth in concrete (there's a certain amount of waste with a pump anyway) and yield a better-cured slab.
> Cheers, W2S
> 
> 
> 
> 
> Forgot to ask this - will this not lead to water becoming trapped between the bottom of the concrete and the dpm?
Click to expand...


If the plastic were not there, the underside of the concrete would be wet most of the time regardless. Concrete (that has no cracks - which of course, for all practical purposes, does not exist) is essentially impermeable.

Good luck tomorrow, I'm sure it will all go very smoothly (pun almost intended)!


----------



## DomD

BigMonka":3l4vy2wh said:


> I can’t add any technical sort of help, but just wanted to say that I love watching threads like this develop so thanks for going to effort of posting it all


Hopefully some quick progress from now on .

Dpm and mesh down, mesh stapled to shuttering.


----------



## DomD

Woody2Shoes":34e2lcku said:


> If the plastic were not there, the underside of the concrete would be wet most of the time regardless. Concrete (that has no cracks - which of course, for all practical purposes, does not exist) is essentially impermeable.
> 
> Good luck tomorrow, I'm sure it will all go very smoothly (pun almost intended)!



Ah ok, I will just trim it down to the bottom of the visible slab after the fact then. Early start at 8 tommorow... I hope the extremely high temperatures (30 tommorow, 37 the next) don't speed up the drying too much.


----------



## DomD

Do I use the poker just on the thickened edges or over as much as the slab as I can?


----------



## MusicMan

I would consider having your electronic bench as a self-contained sealable bench, something like a fume cupboard - could even be an old fume cupboard, rather than a separate room or partitioned-off area. With a deep electronics bench you could have storage drawers/shelves at the back, simple ply or MDF would make the sides and top and carry the electric plugs for the station, and some storage space my be left on top. 

Then in a couple of years when you decide it's in the wrong place, it's easier to move than a room!

Keith


----------



## DomD

This is my planned 'schedule' for tomorrow:
1) Pour concrete and move to fairly even
2) Use poker to compact concrete in trenches
3) Use wooden board to screed concrete
4) Use float to push larger rocks below surface
5) [after I can step on concrete leaving 1/4in impression] float concrete with weight on two boards

I can't believe this but I managed to forget to buy an edging trowel! Is that much of an issue?
Thanks


----------



## DomD

Also forgot about electrical supply...
Done now sketchily - I imagine this will collapse in and I may have to manually place it in the concrete.


----------



## DomD

Concrete poured and screeded - some imperfections but overall ok. Used poker in ditches. Need to float later today.


----------



## Woody2Shoes

Very exciting! Don't forget to cover the top (esp. in this weather!) so it cures properly and doesn't risk cracking (first 72 hours are critical). Cheers, W2S


----------



## DomD

Woody2Shoes":16mj8dq3 said:


> Very exciting! Don't forget to cover the top (esp. in this weather!) so it cures properly and doesn't risk cracking (first 72 hours are critical). Cheers, W2S


Thanks for the reminder! Any ideas how long till I should float - I'm thinking a couple hours but don't want to miss the ideal time.


----------



## will1983

Just keep checking it with your thumb and a float. As soon as it's strong enough to stand on without making a mess of it it's soon enough to start floating.

Don't get to carried away with the floating though, like Mike said it's possible to over work it and get a surface that's no longer really suitable for a floor. A scattering of saw dust on a smooth surface can make it like an ice rink.

Also if you've got any rolls of hessian get that on it after you've floated and give it a good soaking with the hose. You'll have to keep drenching it in this weather or it'll dry out and crack. Concreting is not all about the prep and placing, curing is more important than all with regards to getting a quality result.

Looks like you had a bit of excess there, unless you are keeping that where its lying you need to get it moved as soon as its green enough to break up easily If you wait until it's cured it'll be a pig of a job to break up into pieces small enough to be movable.

Looks good by the way, especially considering you've not done any of this sort of work before. It's certainly more than most people would attempt so hats off to you mate!


----------



## DomD

Keeping it wet, have put dpm over it to slow evaporation. Dug out a lot of the excess and moved to bulk bags.

Very glad it's over with and I can move on to the more fun parts of the build.


----------



## DomD

State of the slab this am - was damp when I removed dpm and adding more water soon to slow drying.

Currently mining out formwork.


----------



## DomD

First two corners laid with help from a relative who is a former bricklayer - good to have someone with experience on hand.
Little slants due to slightly uneven corners (slab itself is flat).


----------



## DomD

What screws should I be using to screw the fir band strapping into the bricks?
Also if I build the longer walls in two sections, is connecting them together with nails through each side stud and at the double top plate acceptable?
Thanks


----------



## DomD

I'm going to use these screws for attaching the strapping.

I have been doing some more brickwork and the back wall is now complete. Frog is up on the top course - should that be filled before dpc goes down?


----------



## DomD

Quite a few bits done over past few days:




First I finished off the brickwork... Not perfect but I'm happy with the two facing sides.





Next I used a hammer drill to drill into the concrete - went through it very easily, I suppose it has not reached full strength yet.





Then I screwed down the metal strapping- first time using an impact driver and I'm confused as to why i didn't get one earlier!





Then I attached the blocks, sawn in half with a dodgy jig so there is some slant in each. There are some gaps between the blocks and bricks which I will fill with grout.





I also got the windows, the big one is 1870*935mm and the smaller is 480*750. I plan to use doubled up 2x8s for the header over the larger.. will put in one trimmer stud which I believe is enough for a window of this size. Is it fine to put the header right up against the top plate and add cripples below so the window could be moved up in future? 
Thanks


----------



## DomD

Did some more earlier this week - hope to get walls constructed and up next week but am away at the moment.





I filled in all the frogs and added a thin layer over the blocks and bricks to create a smooth surface for the frame to sit on. You can see slab is not completely flat as water runs to back - this must have been down to an imperfection in the cleat or bow in timbers.





Then this arrived... all the timber for the walls (and sheathing for everything, 11mm osb).





Then I cut all the studs down to length (2090mm, tall ceilings I know but still below 4m at ridge with 30° roof).





Marking up all the walls, went for a double trimmer for this window in the end. Used 24in oc spacing.





These are my corners (California corners).

Also got a paslode nail gun and will be using 90mm smooth galvanised nails for the frame so it should go together quickly.

Dom


----------



## DomD

Three walls framed today and braced; hopefully last tommorow.




Finished walls.





Measuring diagonals.





Braced walls (with 25*50s).

I am face nailing the frames with 2 3in nails per stud face.


----------



## MikeG.

Great to see your progress, Dom. Like you, I'm always pleased to get out of the ground and start doing "the fun bits".


----------



## DomD

MikeG.":1vh45pau said:


> Great to see your progress, Dom. Like you, I'm always pleased to get out of the ground and start doing "the fun bits".


The concrete definitely stressed me out a bit just because I have never done anything like that before; probably quite a big job for a first.

Quick question on windows. The second hand uPVCs I bought do not come with sills, so I assume along with 5mm on each side for packing I add 40mm height in the opening for standard uPVC sills. This is the only video of UK windows being installed in a timber frame I can find - does that look like the correct method?

Thanks


----------



## MikeG.

Can't help you with your windows. I've no experience of plastic windows, and intend to keep it that way.


----------



## ManowarDave

Can't speak for timber frame but have put in the odd one over the years to brick. The only concern I'd have with timber is over packing the spacers. If the timber swells you might struggle to open the window.

If you are looking at using expanding foam, mask off REALLY well. Sticks like dung to a blanket. And never, ever try to clean it up before it sets...DAMHIKT. After that one experience I've always just used frame sealant to fill the gap.

BTW, his saw in that video had me reaching for a scotch brite pad and some WD40  

Dave


----------



## DomD

ManowarDave":uyo8ewen said:


> Can't speak for timber frame but have put in the odd one over the years to brick. The only concern I'd have with timber is over packing the spacers. If the timber swells you might struggle to open the window.
> 
> If you are looking at using expanding foam, mask off REALLY well. Sticks like dung to a blanket. And never, ever try to clean it up before it sets...DAMHIKT. After that one experience I've always just used frame sealant to fill the gap.
> 
> BTW, his saw in that video had me reaching for a scotch brite pad and some WD40
> 
> Dave


I will make sure not to pack too tight. 

Another question: currently making largest header out of 2x8s but no plywood spacer (window). I'm going to glue then nail the header together before framing the wall. As I have double trimmer studs should I nail one to the king stud first then add the next to that?
I'm also putting header right up against top plate for all openings, and having cripples under that to the top of the opening.
May be too late for advice as I'm doing it now 
Thanks


----------



## DomD

This is the largest header glued then nailed 3in apart on the red diagonals; on the alternate side nailed across the green line at 12in oc. I then nailed this beam to the king studs with 8 3.1in nails a side (4 per 2x).


----------



## MikeG.

DomD":3vhbee51 said:


> This is the largest header........



Stop watching American youtube clips! That's a lintel. :wink:


----------



## DomD

MikeG.":1qhe96qu said:


> DomD":1qhe96qu said:
> 
> 
> 
> This is the largest header........
> 
> 
> 
> 
> Stop watching American youtube clips! That's a lintel. :wink:
Click to expand...

Heh - that's what happens when you get all your info from the web; is it 'trimmer' or 'jack' stud in British English?

The first and second lintels are now in place. Both glued, nailed with the pattern above: for the 2x8 I used 4 nails a 2x8 and for the 2x6 I used 3 per 2x6.

Lintels are right up against the top plate as in images.


----------



## DomD

DomD":l4glmn8u said:


>


Just realised I forgot trimmer studs for the door. Will add later.

Four walls up now but I have lost my helper and can't lift them on my own: rest will have to be tommorow. You can see the walls are quite high (maximum without planning permission).





This is the view from the landscaped steps up:


----------



## DomD

Drawn out plans for eaves detail:




Wondering if that looks okay. I assume the movement of air into the void below the roofing sheets and through the foam filler is enough ventilation? Does the foam filler also act as insect mesh?
Thanks


----------



## MikeG.

You'll find that eaves closer difficult, and it doesn't provide anywhere for the top of the boarding to finish against. Take a look at my workshop build thread at The a different place 2 to see photos of an easier and neater approach.


----------



## DomD

MikeG.":2zht4dqe said:


> You'll find that eaves closer difficult, and it doesn't provide anywhere for the top of the boarding to finish against. Take a look at my workshop build thread at The a different place 2 to see photos of an easier and neater approach.



I have had a look and will switch over to that - looks simpler to execute too. Are those 22x150s against 50x100s? What boarding are you referring to? - as I plan to have exposed rafter tails.
EDIT: after further analysis they appear to be 50x50s and 50x150s

Other than that do you think the voids etc look reasonable and work with the metal box section roof?

Sorry for all the questions 

Thanks


----------



## DomD

All walls up - I nailed the last in too soon and ended up having to use a hacksaw to cut through them to readjust to level.
Double top plate is also on, this is the state it will be left in for ~1week as I go to Scotland. Roof on when I return.
The walls are parallel ±10mm so fairly good I think.


----------



## DomD

As far as loft insulation and wall insulation, is it just cheapest mineral wool with the required thickness? I will be using cavity batts in walls and roll insulation between rafters.

Do I completely fill the rafters leaving no gap between the membrane and insulation or should I get thinner insulation to allow the membrane to sag?

Thanks, Dom


----------



## MikeG.

The membrane should sag. Mineral wool is fine for both.


----------



## DomD

Will that require thinner roll insulation (e.g. 100mm) between the 150mm rafters?
Thanks


----------



## Woody2Shoes

DomD":1fm0cxhl said:


> Will that require thinner roll insulation (e.g. 100mm) between the 150mm rafters?
> Thanks



Yes - normally you'd expect an air gap of about 50mm. Exciting to see progress, cheers, W2S


----------



## MikeG.

Yes. I would allow a 25mm sag, min, so if you can get 120/ 125 thick insulation, then use that. Otherwise, 100mm. You could push 25mm of Celotex into place above 100mm of mineral wool.


----------



## DomD

Thanks both of you, I think from my limited research the larger 50mm gap is for vapour impermeable felt and a breather membrane only requires min 10mm. I will see where I can find 125mm loft roll insulation.
I'm also going to try and use a higher quality membrane on the walls as I may need to leave it unclad for some time.


----------



## Woody2Shoes

DomD":1ffj32ky said:


> Thanks both of you, I think from my limited research the larger 50mm gap is for vapour impermeable felt and a breather membrane only requires min 10mm. I will see where I can find 125mm loft roll insulation.
> I'm also going to try and use a higher quality membrane on the walls as I may need to leave it unclad for some time.



I think that it's worth following the manufacturers instructions for the particular membrane/underlay you actually buy (if you're lucky, on the label, otherwise on the website). My experience is that they all (perhaps excluding the old-fashioned tar-based felts) shrink to a greater or lesser degree. Cheers, W2S

PS re. unclad walls - the main enemy of the membrane is UV light - a good way to temporarily protect whatever you go with is to cover it with black DPM sheet held on with battens


----------



## DomD

Woody2Shoes":sowhgby5 said:


> PS re. unclad walls - the main enemy of the membrane is UV light - a good way to temporarily protect whatever you go with is to cover it with black DPM sheet held on with battens



I've got spare dpm so will look at using it for that. Any recommendations for the membranes for walls and roof? I was looking at the novia ones as they are fairly low cost.





Ridge supports up now. I plan to lift the ridge beam into space tommorow.


----------



## DomD

As I have decided not to do raised ties but regular joists sitting on the top plate, does it make sense to do them first?


----------



## MikeG.

There are arguments either way. You _could_ do the joists first and put down some temporary boarding on them to enable easier access to the ridge, then do the ridge, then the rafters. However, you'd have to fix battens etc to the joists such that they were safe from falling over. Or you could do it the orthodox way.........rafters first.


----------



## DomD

MikeG.":1y5bomrv said:


> There are arguments either way. You _could_ do the joists first and put down some temporary boarding on them to enable easier access to the ridge, then do the ridge, then the rafters. However, you'd have to fix battens etc to the joists such that they were safe from falling over. Or you could do it the orthodox way.........rafters first.



That's what I was thinking with the boarding as I have no scaffold and the top plates are at 2.5m. Why would I need to fix battens if I have nailed down the joists?


----------



## MikeG.

Because tosh nailing doesn't provide much rotational resistance.


----------



## DomD

Ok I will use some battens I have spare.

Another question: you can see the sheathing here is just short of full height:




The osb at the top will cover part of the gap but I was wondering if it would be acceptable to leave ~1" gap at the bottom to be covered by the skirting board - I am assuming the bricks are vapour impermeable anyway so do not need the osb as a vapour barrier?
Also are there advantages to laying two sheets offset horizontally rather than one sheet vertically?

Thanks again for all your help,
Dom


----------



## MikeG.

It's fine to leave a gap at the bottom and cover it later with a board. The problem laying boards landscape rather than portrait is that the horizontal join might be unsupported (ie no timber behind it). If you've got noggins around the building at the right height then fine, it makes no difference at all.

I don't know if your straps are fixed in place yet, but if they aren't, see if you can move them away from the edges of blocks. They're stronger if they are at least 3 or 4 inches in from the edge of a block.


----------



## DomD

MikeG.":bk1w5crz said:


> It's fine to leave a gap at the bottom and cover it later with a board. The problem laying boards landscape rather than portrait is that the horizontal join might be unsupported (ie no timber behind it). If you've got noggins around the building at the right height then fine, it makes no difference at all.
> 
> I don't know if your straps are fixed in place yet, but if they aren't, see if you can move them away from the edges of blocks. They're stronger if they are at least 3 or 4 inches in from the edge of a block.


That makes sense - I'll do vertical then. 
Already screwed down unfortunately but quite a few are away from edges and I did a fair amount more than recommended on your diagram.

Currently on the joists putting in the ridge - you can see the gap of three joists:





Dom


----------



## DomD

Ridge up! Unfortunately it is fairly bowed with a 4cm difference from eaves to ridge at opposite sides - I suppose I just put the rafters on the short side in first to push it into place?

Regarding rafters, is the best way to cut them just with a circular saw and is there any way to get around having to lift the guard manually when making the seat cut? Should the rafter tail be cut afterwards?

Thanks


----------



## MikeG.

Put the rafters up in pairs, and tap the high one down. They'll soon pull the ridge straight. You will probably find it easiest to use both a circular saw and a hand saw for cutting the rafters. Clearly mark your pattern piece, and wear goggles, because precision circular sawing involves looking at the blade, not the mark on the base, and that means getting a face-full of sawdust.


----------



## DomD

Half of the rafters are now up:





I cut them by lifting them onto my saw horses cutting one of the angled sides with my mitre saw and doing the rest with a circular saw. My circular sawing certainly could use some improvement but I think the birdsmouths look reasonable:





The nailing schedule I have used for the roof is:
Joists to top plates: 4x 3.1in toenails
Rafters to top plates 3x 3.1in toenails
Rafters to joists: 3x 3.1in face nails
Rafters to ridge: 3x 3.1in face nails

There is lots of space in the 'attic' area for storage - I'm glad I didn't raise the ties.





Dom


----------



## DomD

Looking at roof and wall structure now:
For the roof I will have the breather membrane draped over the rafters and hanging over the end of the building enough to run into a gutter. Then will be battens at 1000mm centers and a metal box sheet roof.

The walls I am planning to use a breather membrane, battens at 500mm centers and then the feather edge. Corners will be this:





not as elegant as Mike's solution but quicker and requires no rip cuts.

A few questions:
Is there any way to cover the breather membrane from below the rafter tails (so when you look up you see something other than just a membrane)?
How is the void between the roof battens ventilated? 
How is the gap behind the top of the featheredge in the 'How to build a shed' diagram created with this eaves detail?

Thanks, Dom


----------



## MikeG.

Waaaaaaay too many nails. You'll knacker the timber.


----------



## DomD

Ah right.. what should I be using then? They are just schedules I have found online. I could cut down to two each?


----------



## DomD

Gable roof almost done - couldn't do final four sets of rafters as my last jigsaw blade, used to cut the notches for lookouts, broke.
Also added some of the eaves closers.


----------



## DomD

I was test fitting the sheathing today and have found a problem where it overlaps onto the blocks. Because of bowed timbers and slight misplacement the osb is unable to lie flat on across the overlap.
I see too potential ways to go around this:
I could just nail the sheathing on down over the blocks or I could cut the sheathing so it does not go below the timber frame; I would then need to find something to cover the blocks later.


----------



## DomD

Gable ends done; I added a 2x4 above the ends as a point to attach the sheathing.

Still unsure how I will solve the above issue if anyone has any ideas. Perhaps I could add some osb spacers between the sheathing and frames?

Dom


----------



## DomD

Another question: do I need threaded rod through the ties even though they lie on the top plate? Thanks


----------



## MikeG.

Four nails equals a bolt, I think. So two or three nails from the tie into each rafter end, and one or two into the plate, and you then don't need a bolt. Personally, I wouldn't nail so often, and I'd bolt, say, every third tie.


----------



## DomD

I've already nailed enough then so won't put them in.

Lots of progress - installed both gable ladders, planed down all eaves closers and have begun sheathing the inside with osb.





The more time I spend on this the more I want to put something nice on the roof. I was having a look at clay tiles (used lots in our area) and may use them instead of a sheet.

I also am regretting not planning to put roof windows in - I know they are an extra expense but would provide far more light than the large window. 
Would cutting through a rafter and adding double 2x6 'lintels' above and below the window opening be a possibility? The velux ones seem fairly straightforward to install.

Thanks


----------



## MikeG.

If you are planning on using tiles, then cutting a rafter and trimming an opening is only do-able if you double-up the adjacent rafters.


----------



## DomD

MikeG.":1myl4mr7 said:


> If you are planning on using tiles, then cutting a rafter and trimming an opening is only do-able if you double-up the adjacent rafters.


If I were to install a proper (e.g. velux) roof window on an onduline roof (I checked and this is supported) would the extra rafters be required?

I have sheathed a gable end wall. The tops and bottoms are not nailed as they have nothing to nail onto; I assume that's not a problem as gable end walls are non structural?

Thanks


----------



## MikeG.

Put something on the plate (scraps of batten off-cuts, for instance) so that you can get some nails in along the free edge of that sheathing. You don't want flapping bits of OSB, as it can soon take on a shape of its own.

If you have an Onduline/ Coroline type roof then you probably don't need to double up the rafters around a trimmed opening......but check first that Velux have a suitable flashing kit for that type of roofing. You wouldn't want to end up with a hole you couldn't fill.


----------



## DomD

MikeG.":1hsnunra said:


> Put something on the plate (scraps of batten off-cuts, for instance) so that you can get some nails in along the free edge of that sheathing. You don't want flapping bits of OSB, as it can soon take on a shape of its own.
> 
> If you have an Onduline/ Coroline type roof then you probably don't need to double up the rafters around a trimmed opening......but check first that Velux have a suitable flashing kit for that type of roofing. You wouldn't want to end up with a hole you couldn't fill.


Ok, will do that with the battens

Velux have a section in their guide for profiled sheets and have confirmed it works with coroline, I will just need to add a sheet overlap at the right place.


----------



## DomD

All walls boarded and a window routed out, just need to finish the gable, then on to the roof.


----------



## DomD

Final gable end boarded:





Then I went onto the roof window opening, dark photo unfortunately:





There are certain places (e.g. under the lookouts) that 100mm insulation won't fit, should I just be filling this with expanding foam?

Finally, should the roof be boarded with osb horizontally or vertically?
Thanks


----------



## MikeG.

OSB: whichever way suits. And yes, if you can't get 100mm of insulation in, then get in what you can. With solid stuff either side, expanding foam is fine and a useful weapon in your armoury.


----------



## DomD

Ok, I have a gun so should be easy enough to apply.

Did the lower parts of the roof today:




There are definitely gaps e.g. between boards and around the cutouts but hopefully not large enough to compromise the vapour barrier.

Do I just leave these sheets flying top and bottom? I will add an off-cut for the edge on the unsupported side of the cutout.

I then put one upper board up which took two people and lots of work 




- others won't go up until Saturday as I am out of osb; hopefully wall insulation and membrane tommorow.

Dom


----------



## John15

I'm enjoying your workshop build Dom. It's making my workshop look pretty shoddy!

John


----------



## DomD

John15":3eeavj0e said:


> I'm enjoying your workshop build Dom. It's making my workshop look pretty shoddy!
> 
> John


Glad you're enjoying it, I'm avoiding taking photos of all the minor mistakes! 

I've got the drip edge in now, onto cutting insulation.


----------



## DomD

Door detail:




Corner detail:





Unconvinced about these but that seems the best I can get - should I fill any potential ingress points with silicone?


----------



## DomD

Wall insulation done






Just adding the membrane now but it's not going too nicely around the corners. I may just make a cut and seal it with the tape?





Will hopefully finish later tonight.


----------



## DomD

Have now done membrane on roof and walls - just gable ends to go.

First I put it on the walls:





Then I finished boarding the roof and added insulation









Today I did the roof membrane. Really hard to get right, didn't help that I didn't realise you put battens on as you went, but the wind was what really made it tricky. 
This was the first side I did, not perfect but I think the creases are exaggerated in the photo:





The back side went on perfectly:




Then I used a makeshift 'roofing ladder' to do the taping:





I then added a ridge sheet but it was too dark for photos.

I have left this tonight with no battens on, though there are quite a few staples and the sheets are taped; hopefully it survives. I will add battens tommorow though may have to be temporary as not 100% on spacings.

I did have to staple below the overlap due to the high winds, will this impact the waterproofness of the membrane?

Dom


----------



## mindthatwhatouch

Hi Dom,
Cracking along nicely.
I may be a bit late with this but for the membrane, if you nail a metre length of temporary batten through the start of the membrane (ie on the fascia for the roof, or around the corner on a wall) leave the nails proud so you can remove it later. It holds the fabric nice and tight when you lay it out then do the same at the other end of the roof or wall. Once you’ve battened it out you can remove the temporary batten and cut the excess membrane.
It’s one of those jobs that an extra pair of hands goes a long way, especially when it’s windy.


----------



## MikeG.

mindthatwhatouch":1bwqlshj said:


> ......It’s one of those jobs that an extra pair of hands goes a long way, especially when it’s windy.



It's _always_ windy when you use a membrane! It seems to be one of those immutable laws of nature.


----------



## DomD

Battens now on the membrane, rained last night and dry inside.





Now I just need some doors - you can see the start of what I was doing in the interior photo.


----------



## John Brown

Sorry for the dimb question, but dou you nail the battens on through the membrane?


----------



## DomD

John Brown":1wiokebi said:


> Sorry for the dimb question, but dou you nail the battens on through the membrane?


I did and I think that is the right way as the battens need to be attached to the roof structure.
I assume the batten forms a seal, and water instead runs down over the membrane in the sag between the rafters.


----------



## DomD

For the door I am planning on a structure of OSB->insulated 4x2 frame-> shiplap. I think I will try to bend the hinges as demonstrated on Mike's workshop thread.

Is it a good idea to have breathable membrane over the frame (and perhaps a batten ventilated void) behind the door cladding? This would thicken the door quite a bit.

Also, what paint/primer should I be using over the OSB and how should I apply it? I have heard the cheaper HVLP spraters work resonably, though I could just use a roller.
Thanks


----------



## MikeG.

Just be careful that door isn't too heavy. It sounds a monster.


----------



## DomD

MikeG.":o2j1za3r said:


> Just be careful that door isn't too heavy. It sounds a monster.



I will see - maybe can leave the OSB off it.

I think I will use a couple coats of white masonry paint on the OSB3 - I've read this way I won't need to prime? I have also seen bedec barn paint recommended - unsure of how reliable any of this information is!


----------



## MikeG.

Painting OSB (inside the building) can be done with the cheapest emulsion you can lay your hands on. There is absolutely no point using expensive paints such as Bedec or a masonry paint. Save Bedec for outside.


----------



## DomD

MikeG.":1zd8lcua said:


> Painting OSB (inside the building) can be done with the cheapest emulsion you can lay your hands on. There is absolutely no point using expensive paints such as Bedec or a masonry paint. Save Bedec for outside.


But will it need primed if I use cheap emulsion? If so what with?

Thanks


----------



## MikeG.

No, no primer required. The first coat should be watered down a bit.


----------



## DomD

Slower progress - I did install the windows:




Only to decide the white really doesn't fit with the building... I will be getting some custom sized wooden ones; if anyone has used any companies for windows I would be open to recommendations.

Then I made a door and similarly dislike the result; Mike was right about the design being too heavy so I will replace with a shiplapped/t+g door.





I also finished off gable insulation:





Onduline has been ordered for installation next week. Am I correct to assume the 'sag' in the roofing membrane would allow insects into the void below the onduline? If so how do I seal this? The corrugation profile will be sealed with a foam eaves filler above a batten.

Could the ridge also act as an opening?

Thanks


----------



## beech1948

I can not see from your last picture but Onduline will sag between the roof members such that over 5 yrs you will have a 3" to 5" sag which collects and holds water. Onduline has no strength to resist this. Guess how I know this.

If still using Onduline then you need to provide either ply (1/2") or 3/4" OSB for the Onduline to sit on.


----------



## DomD

I have begun installing the onduline:





I have looked online and as far as I can tell I need eaves but not ridge ventilation (see http://www.nhbc.co.uk/Builders/Products ... s2019/#317). I will use comb fillers at the eaves and just fill the ridge profile with foam fillers.
Eaves shown here where gutter will go:





I damaged the sheeting a few times during installation:







Is there a good way to repair this? I am planning on using roof and gutter seal.

Thanks


----------



## MikeG.

Yeah, that's your best answer.

You seem to have plenty of battens in support, so sagging won't be an issue. However, I'll warn you now that your roof will be black, not green, within 5 or 7 years. I did a workshop of mine in green, like yours, and it was identical to the black stuff by the time I sold the house.


----------



## DomD

beech1948":3nw18hzi said:


> I can not see from your last picture but Onduline will sag between the roof members such that over 5 yrs you will have a 3" to 5" sag which collects and holds water. Onduline has no strength to resist this. Guess how I know this.
> 
> If still using Onduline then you need to provide either ply (1/2") or 3/4" OSB for the Onduline to sit on.



I have supported it with battens at half the specified span for my pitch (had to due to membrane requirements). They guarantee it for 15years if installed correctly and some say it can last much longer; hopefully that means I'm ok!


----------



## DomD

MikeG.":1qmyuwje said:


> Yeah, that's your best answer.
> 
> You seem to have plenty of battens in support, so sagging won't be an issue. However, I'll warn you now that your roof will be black, not green, within 5 or 7 years. I did a workshop of mine in green, like yours, and it was identical to the black stuff by the time I sold the house.



Hmm that's a shame as the green costs a fair amount more; it will be nice to have it at the start anyway, the idea was to blend in with the trees.


----------



## MattyT

Great project. I would like to build a smaller version for my garden.


----------



## Dibs-h

DomD":6vod5dji said:


> Slower progress - I did install the windows:
> 
> Only to decide the white really doesn't fit with the building... I will be getting some custom sized wooden ones; if anyone has used any companies for windows I would be open to recommendations.
> 
> Thanks



Looking good there Dom. On the subject of windows - you could leave the existing ones in for the moment and then make some. I'd never made any and had a go and was (is still) very happy with them.


----------



## DomD

Dibs-h":1g57yrtl said:


> DomD":1g57yrtl said:
> 
> 
> 
> Slower progress - I did install the windows:
> 
> Only to decide the white really doesn't fit with the building... I will be getting some custom sized wooden ones; if anyone has used any companies for windows I would be open to recommendations.
> 
> Thanks
> 
> 
> 
> 
> Looking good there Dom. On the subject of windows - you could leave the existing ones in for the moment and then make some. I'd never made any and had a go and was (is still) very happy with them.
Click to expand...

After looking at the price of new wooden windows that's what I think I'll do. Those windows look great!

I may paint them in the meantime, I think grey frames would look reasonable despite the thickness.

I have finished the first row of onduline but other than that progress is slow due to seemingly constant rain.




Hopefully I'll get the roof window in on Saturday.
Dom


----------



## DomD

Window mostly installed other than final flashing. I covered it with some spare breather membrane in the meantime.











This is the flashing around the top gutter which should be fine as far as I can tell but the instructions are unclear.


----------



## DomD

Roof light fully flashed:





I'm really struggling to get the sheets on around it though. See here where I installed a sheet over the bottom flashing:




The sheet lifts up which could allow water to be blown up over the overlap and I can't nail them down as that would be through the flashing. Not sure what the correct way rectify this is; any ideas appreciated.
Dom


----------



## Dibs-h

Can you not use some of those fixings that are lower down in the last picture? Or is there no lath directly underneath where you would screw down? Just thinking out aloud.


----------



## DomD

Dibs-h":3iq4ah70 said:


> Can you not use some of those fixings that are lower down in the last picture? Or is there no lath directly underneath where you would screw down? Just thinking out aloud.


Yeah I can't fix any further along (would be over the flashing) or lower (would not be over a batten). I think I will have to rip up some of the onduline sheets and have this overlap go over onto the next batten. 
Dom


----------



## DomD

I layed a longer sheet over the flashing and fixed below, there is a small bump but it doesn't lift at the bottom anymore.


----------



## DomD

Roof now basically finished - but I am one ridge piece short!
I made a 'ridge board' with a 2x2 and a batten





Then added the ridge all along with foam fillers. This means no ventilation at the ridge but I will use comb fillers at the eaves to allow airflow.








Next it's the internal wall, painting then electrics. I'm going to run a 10mm² swa cable for 40A in the shed. That should be enough to run the heaters (4kW), lights and some tools.


----------



## MikeG.

The electricity needs to be certified by a qualified electrician, who'll need to test everything including earthing. Leave the calculation of the cable size to him. He'll need to wire up the consumer unit, which isn't a DIY job. Many electricians will let you run the circuits for the sockets and lights, and simply check inside a couple of the fittings to see that you've done it properly. Otherwise, leave the electrical connections to a professional.


----------



## DomD

MikeG.":1x0poy40 said:


> The electricity needs to be certified by a qualified electrician, who'll need to test everything including earthing. Leave the calculation of the cable size to him. He'll need to wire up the consumer unit, which isn't a DIY job. Many electricians will let you run the circuits for the sockets and lights, and simply check inside a couple of the fittings to see that you've done it properly. Otherwise, leave the electrical connections to a professional.


Yeah should have specified but this was discussed and will be done with an electrician.
Dom


----------



## Krysstel

10mm2 is what I'm running to my Norwegian Wood(shop)
It was sized for me by the electrician that will be doing the installation work.

Off that I'll have 4 circuits, 1 of them 3-phase (we have 3-phase 230V here).
And of the single phase circuits; 1 separate circuit for lighting, 1 separate for extraction and 1 for all the rest.

Mark


----------



## DomD

Krysstel":3swcydwq said:


> 10mm2 is what I'm running to my Norwegian Wood(shop)
> It was sized for me by the electrician that will be doing the installation work.
> 
> Off that I'll have 4 circuits, 1 of them 3-phase (we have 3-phase 230V here).
> And of the single phase circuits; 1 separate circuit for lighting, 1 separate for extraction and 1 for all the rest.
> 
> Mark



Lucky to have 3 phase available, I'm going to have a 32A circuit for plugs, 6A for inside lighting, then 2 9A circuits for heating (my electrician wants to split it). I imagine I will just run extraction from sockets and if I do get anything permanent installed just plug it in.

For the internal wall I think I may as well insulate it; if I am heating only the inner room will having OSB on both sides of the wall cause problems? I suppose any vapour would condense on the inner vapour barrier.

I also am wondering if I need to add OSB around the skylight as a vapour barrier? This is done in houses.

For lighting I think I will use LED panels unless anyone has other suggestions. One for the smaller room, in the vaulted ceiling opposite the skylight and one in the entrance area. I may also put a LED tube in the 'loft' area which I am boarding and using for storage.

Dom


----------



## DomD

Attic boarded with 18mm osb - maybe a bit over the top.




I also boarded a shelf on the opposite side. I screwed 2x2s into the wall structure at each side to support the edge of the sheets.

Then I moved onto the interior wall, first laying out with a chalk line, then fixing the sole and top plates. I used multifix screws - not intended for anchoring but work fine here I think. I sealed the dpc hole with roof and gutter seal.









I decided to add space for an internal window to let light from the large windows into the small room; this explains the framing for the left wall.









The joist above the wall had been placed crown down so the top plate is actually slightly angled; only a few cms drop across its length though.

Next will be sheathing and insulating the internal wall.
Dom


----------



## Gareth79

I'm going through this thread because it's pretty close to what I figured out I want to build, lots of good information many thanks to all! I'll post my own thread soon I think with some ideas to get some comment on before I submit for planning permission (I'll need PP because it will be within 2m of a boundary and I want a decently pitched roof).

One question - DomD what software did you do the framing designs in?


----------



## DomD

Gareth79":17tmg8kp said:


> One question - DomD what software did you do the framing designs in?


It's in fusion 360 which isn't really designed for it but works alright. In reality though I didn't stick to locating the framing as in the model when I built it and instead just marked based on spacing. Model was more for material estimate.
Dom


----------



## Gareth79

DomD":epf3oz5d said:


> Gareth79":epf3oz5d said:
> 
> 
> 
> One question - DomD what software did you do the framing designs in?
> 
> 
> 
> It's in fusion 360 which isn't really designed for it but works alright. In reality though I didn't stick to locating the framing as in the model when I built it and instead just marked based on spacing. Model was more for material estimate.
> Dom
Click to expand...


Thanks, yes I think learning another piece of software is probably too much effort for me! I have used Revit to do the overall design, which will do me fine for the planning permission drawings, and I then I can manually work out the rest. I have gathered that studwork is generally not precisely planned out (the same as a bricklayer isn't told how to lay each brick), but as you say for a DIYer it's necessary to get a fairly close estimate to avoid ending up with too much or (worse) too little timber.


----------



## DomD

I have now rolled on three coats of emulsion on all surfaces; I was planning on doing the attic too but that seemed a waste of time so instead I added a wooden 'border' and painted up to that.

After the first coat it looked like this, this was a slightly watered down coat:





Then the final two coats:




Not perfect but good enough I think.

I'm putting the electrics in with my electrician before New Year; he has persuaded me to use plastic conduit to keep things neat. These will go directly into metal-clad socket knockouts. There are going to be four circuits: 6A interior lighting, 6A exterior lighting (security lights & maybe other), 32A sockets, 20A heating.
I'll post some photos when its done!
Dom


----------



## flying haggis

are you wiring the socket outlets in 2.5mm t&e? if yes use 25mm conduit as you/he will struggle to get two cables in 20mm conduit


----------



## AJB Temple

Add at least one 16amp outlet. Sods law dictates that at some stage a bandsaw or PT that you buy will require it. Costs peanuts at installation time.


----------



## DomD

flying haggis":1kwlwavj said:


> are you wiring the socket outlets in 2.5mm t&e? if yes use 25mm conduit as you/he will struggle to get two cables in 20mm conduit


I believe it is 2.5mm t&e but the electrician seems confident we will be able to get two cables in each 20mm conduit. That should be the max that is ever going down/up a conduit run.
It's all bought now so hopefully will work out.




AJB Temple":1kwlwavj said:


> Add at least one 16amp outlet. Sods law dictates that at some stage a bandsaw or PT that you buy will require it. Costs peanuts at installation time.


I think it's going to be too late now - I could always add one in the future if needed.

Dom


----------



## DomD

Socket back boxes in:






Consumer unit (ring main, heating, lighting circuits coming out of top):





Sockets under window:





Hopefully finishing everything off tomorrow.


----------



## DomD

All second fixing finished in the shed, only thing left to do is connect power and ethernet at the house end.
The supply runs next to an cat5e cable in corrugated conduit; both run on the surface along our fence.

Eye level sockets for standing height workbench




Heater wired in




Low level sockets in electronics/computer room




Panel lighting, yet to see if these will be bright enough





The conduit did add a fair amount of time but looks really good in my view; wiring in the 'loft' clipped direct as it's not really visible.
Dom


----------



## DomD

All electrics finished off.




Works great at night - no more chained extension cords.
Dom


----------



## BigMonka

That’s looking fantastic Dom, it was only a page ago that it looked like a building site and now it’s a proper workspace.
What are those square lights that you’ve got? I’m thinking about upgrading my lighting so would be interested to hear how you get on with them.


----------



## flying haggis

it might be in the wrong place but you could add a 16A socket or two directly under the consumer unit


----------



## DomD

BigMonka":3qjlw0d1 said:


> That’s looking fantastic Dom, it was only a page ago that it looked like a building site and now it’s a proper workspace.
> What are those square lights that you’ve got? I’m thinking about upgrading my lighting so would be interested to hear how you get on with them.



Really enjoying using it already, the lights are 60*60cm led panels - usually found in offices I think but work great.



flying haggis":3qjlw0d1 said:


> it might be in the wrong place but you could add a 16A socket or two directly under the consumer unit



Yes if I needed to that wouldn't be too much work.
Dom


----------



## DomD

One issue I have found is some mould growth distributed across the walls and roof. 
I hope this is just due to the fact I have not managed to get the door and window in yet leading to some condensation paired with the recently applied water based paint but thought I would mention anyway.






Any ideas of the best way to deal with it? Should I be removing it or just leaving it as is? I have seen some products that claim to help keep it from growing and also anti mould paints, but unsure if this is necessary.

Dom


----------



## DomD

Almost sealed so mould should become less of a problem once that's done.

I installed the window frame tonight:





As you can see I did put a dpc down. Not sure if needed but I figured it shouldn't hurt. 
Then I put a bed of silicone and added the window on top - later realised I probably shouldn't have added silicone at this point, instead should have filled the cavity with expanding foam and then added a final silicone seal.

Screwed in:





If there is anything I've obviously done wrong let me know so I can fix it before I put the panes in!
Dom


----------



## Brian H

Hi Dom,

A very nice build project. I came to this board when I googled 'building workshop' for ideas... wow did I land at the right place  

I'm hoping / planning on finishing my single car garage in the spring / summer so will linger on the boards whilst I learn the correct approach.

Thanks for sharing, there are many of us 'hanging around' on these boards learning from kind folk who share their experiences.

Cheers
Brian


----------



## flying haggis

excuse me asking, but what is the thin cable that comes from the socket to the right of the c/u for


----------



## DomD

Brian H":3kpkebjw said:


> Hi Dom,
> 
> A very nice build project. I came to this board when I googled 'building workshop' for ideas... wow did I land at the right place
> 
> I'm hoping / planning on finishing my single car garage in the spring / summer so will linger on the boards whilst I learn the correct approach.
> 
> Thanks for sharing, there are many of us 'hanging around' on these boards learning from kind folk who share their experiences.
> 
> Cheers
> Brian


Glad to hear it's useful, make sure to look at Mike's drawings and build for the specifics.



flying haggis":3kpkebjw said:


> excuse me asking, but what is the thin cable that comes from the socket to the right of the c/u for



The black one is an ethernet cable - there will eventually be a shelf infront of it for a router.





Dom


----------



## DBT85

Dom, it's been just over a year since your adventure started and its a great thread to go through and get info and tips for doing my own.

Can I ask how you feel about the onduline roof and also what provision if any you've made for the rain water?

Also the most important question, how have you fared in terms of budget? Is there any chance you have a breakdown of costs?


----------



## DomD

DBT85":3ecpnwfs said:


> Dom, it's been just over a year since your adventure started and its a great thread to go through and get info and tips for doing my own.
> 
> Can I ask how you feel about the onduline roof and also what provision if any you've made for the rain water?
> 
> Also the most important question, how have you fared in terms of budget? Is there any chance you have a breakdown of costs?



Sorry for the delay in response - didn't get a notification for some reason.
The onduline has been great so far - it blends in well with the surrounding trees and its ease of install made it worth it for me.
Regarding budget I haven't been keeping too close track - the key major costs were electrics (though you could save on this if you wired the sockets - I got an electrician to do everything) and the concrete base (which I had to get pumped). Also mistakes etc and buying too much have contributed to cost.

Dom


----------



## DomD

Slow progress but I made a few doors (shiplap fixed at one side for expansion/contraction).





I then moved on to dealing with the mould mentioned above - I left it for a while with the building unsealed so it did get a bit worse but after sealing and drying for a while it just wiped off.

I then replaced the other pvc window and glazed both windows.

Frame in:





Sealed unit with bitumen strips applied:





Toe and heeled in then fully bedded in flexible silicone:





And beading nailed in (I'll need to sand off the silicone stains, it will be painted over anyway):





And then the main window:





Very happy with the change in windows - will make the end product when cladding is on look much better in my view.

I'm currently going round installing combs under the onduline and then it will probably be summer before cladding!

Dom


----------



## DomD

As I am working from home, I anticipate having a little more time on this so am looking to get the stuff for the cladding early next week.

I intend to use 150mm featheredge board for the cladding. These will sit on 25*50 counterbattens at 400mm intervals. The boards will be nailed in as reccomended here with 63mm galvanised ring shank nails.

The featheredge I will use is 15mm at its thickest down to 5mm at its thin end. Is there an optimum angle for these or should I just base the angle off the overlap (I intend to use a 40mm overlap)? Am I correct in thinking the bottom board will have to have a greater angle so the edge of the featheredge overhangs? 
I also realise I will need to make some wedges similar to those Mike used for the bottom boards - I am unsure how to do this as I have no bandsaw. I will be routing the cove into the bottom board
I will install insect mesh at the bottom of the ventilated void as Mike has done in his build. 

For the cladding termination at the eaves I am still not sure what the best way to add the insect mesh is. Ideally this would also cover the currently exposed roof membrane atop the rafter tails.

For the corners I intend to use this detail:
https://www.vastern.co.uk/wp-content/uploads/2014/07/Advice-cladding_Solid-block-corner-300x300.jpg

For windows/doors are there any reference details? I assume water needs to be able to run out over windows? Currently I plan to use 22mm*45mm around the windows nailed into an adjacent batten.

Finally for painting: I believe I need to leave the treated cladding up for sixth months before painting so I will check back then! I plan to use semi-transparent bedec. As far as exposed rafter tails/bargeboards go - should these be treated in some way?

Many thanks, Dominic


----------



## DomD

Unfortunately I didn't manage to get the cladding before the supply chain had shut down so I have been focusing on other things.




Added some hasps and staples on the doors. The left door bolts into a hole in the wooden frame slab. Both hasps and staples screw into the ledges behind.






I then built a small workbench with 4x2s and 11mm plywood. This is in the 'electronics' room so is more of a desk than a bench. I have ordered twinslot for shelving test equipment.

I then added some trim around the windows on the inside. These are made of spare battens rounded over and with a cove on the inside so small protrusions don't mean it can't line up flush. I plan to bed these in with silicone and nail them into place.

Before:





After:





I've also been adding the combs around the roof which I have left far too long!
I've got a pine door on order which I should hang in the next few weeks.
Dom


----------



## DomD

Since the last post I have moved lots of stuff in and also installed a door to the smaller room:



Cladding is still to come!

I am currently trying to work out how I am going to do the soffit (which covers the breathable membrane on the roof from below). 
At the front of the building this is fairly straightforward:



I'm just attaching a batten cut in half to each side of the rafter which painted 8mm shiplap cladding will be nailed to. At the front the soffit will be closed with a small fascia that only extends partially down the rafter-ends.

The sides are slightly more complicated and I think I am going to do it like this:




A 45*45mm timber will run all the way down the gable end to the corner this will act as the 'termination point' for the featheredge. Atop this piece a timber will be attached to nail the shiplap into and it will be nailed in similarly at the other end. This has the disadvantage that the cladding will not cover the lookouts holding the flying rafter, but if I wanted to cover those the shiplap would need to come much further down.
Directly below the 45mm post will sit a diagonal batten (not pictured). where the featheredge flying end will be fixed.

Hopefully that all looks fine - I don't think I need to provide ventilation as the membrane above the void is breathable.

Dom


----------



## DomD

Today I made up the main window reveal. I decided to cut the sill flush:





As suggested by Mike, the pentice board at the top is sloped and will have dpm that slides under the breathable membrane running onto it. I think I will fill small gaps (e.g. between sill and side reveal) with some sort of sealant.

Dom


----------



## MikeG.

You can do that, Dom, but think very carefully. It works both ways, because gaps let the water in, but they also let water out. Make sure you don't create a little pocket where water can get trapped inside the structure.


----------



## DomD

MikeG.":3njvqfzd said:


> You can do that, Dom, but think very carefully. It works both ways, because gaps let the water in, but they also let water out. Make sure you don't create a little pocket where water can get trapped inside the structure.



Ok - I will try to leave exits for the water to run off. Perhaps I don't need to between the reveal timbers but still may between the window frame and the side reveals to prevent water getting in.

I finished the day working on the corners - I wanted to do the narrower ones but it wasn't going to work with the way my roof overhangs, so I ended up with this:




It's two battens, one overhanging slightly, paired with a 55*45mm (ripped from a 4x2) which together create a protrusion of 55mm from each wall (where the featheredge will butt). I ran out of 4x2s so it's just a short piece for layout - the full pieces will be painted the same as the cladding.


This is how the corner merges with the gable wall:





Hopefully that all looks good!
Dom


----------



## DomD

Battening out the walls:












I also added another pentice board above the door as it was previously flat - DPC is on its way but I've used a whole roll!




Dom


----------



## DomD

Wedges on - these are all slightly different angles as the timber frame wasn't exactly parallel to the foundation.





I'm think it might be a good idea to put a coat of bedec on the untreated face. 
I will need to fix the first featheredge board along its centre to ensure it is secure (the wedges overhang quite a bit). The above boards will be fixed normally, just above the lap.


----------



## DomD

Starting to paint - this first coat is watered down 30% and I'm using a roller to apply it.


----------



## DomD

This is what I have come up with for the bottom of the corner:








It's not ideal that the brick sticks out slightly but I think it is better than the corner coming out any further. This issue is due to the thickness of the plinth varying such that at this particular corner it is slightly wider than the others.


----------



## DomD

I have been doing the second coat of paint on the boards over the past few days and am almost ready to start cladding.

I went around the building and got the insect mesh in place, stapled into the wedges and tucked under the dpc. The face of each wedge is painted as it is untreated - probably not necessary but decided it couldn't hurt.








I then made up some spacing crosses in preparation for putting the cladding up:








I'm going to have to fix the bottom board just below the overlap rather that 35mm from the bottom as it wont screw through into the batten otherwise. This does mean shrinkage/expansion will move the bottom of the board more, but this should only be up to ~5mm.
The first boards will be fixed with stainless steel screws and the rest will be nailed 35mm from the bottom of the board. I'm fixing all the boards with their cupped side in so the nail pulls them flat.

On an unrelated note, I was at the dump getting rid of some of the waste timber and someone was about to throw this into the scrap metal bin!




In good enough condition just needs cleaned and repainted.
Dom


----------



## DomD

Boards going up - I started with the back in case I made any mistakes. I forgot to put the dpc on to protect the bricks from paint, not too bothered for this side and will just be careful when painting.








The corner:





Really happy with the colour and how it goes with the roof.


----------



## DomD

The cladding is finally (almost) all on - I still need to do the top boards at the front and back but am waiting for an electrician to check my light wiring.









I also painted the windows and they look great with the boards around them. Need to clean the glass!









The lights are wired through the voids between the battens. There are two PIR sensors which I recessed into the featheredge and painted; they turn the lights on when it's dark and they detect movement. I used three core + earth so there is also a 'switched live' going to the lights which overrides the sensors if I want to keep the lights on.

There is a bit of discolouration in the boards, I think this is due to the temperature I painted them at. I am going to do a full repaint of the outer face in Summer [3rd/4th coat for most boards].

The heaters and insulation have worked very well this winter and the shed heats up in ~10mins with the 2x2kW heaters.

I think I am going to paint the door the same colour as the cladding but am not sure yet.


----------

