DBT85s Workshop - Moved in and now time to fit it out

[DBT85]

Some links to jump to points of interest
22/05/2020 - Ordering begins
27/05/2020 - Groundworks Begin
03/06/2020 - Concrete is down
06/06/2020 - Bricklaying starts
12/06/2020 - Framework begins
15/06/2020 - Walls are up
22/06/2020 - Framing complete
25/06/2020 - Roof insulated and membraned
15/07/2020 - Roof tiled


Time Lapse videos
Part 1 - Site clearance
Part 2 - Digging a hole
Part 3 - Filling it up
Part 4 - Brick and Block
Part 5 - Framing

Well while Coronavirus may almost certainly put an end to any hope I had of getting this done in 2020 (I'm a freelancer who broadcasts sport...so its going to be a long year!), I figured I'd start getting things down and plans on show so that I can find out what I'm going to be doing wrong and fix some of it before I get there. That'll all also help me budget better and get more ideas on various stages. Needless to say I've read up a lot on other threads!

Right now I have a workshop in my house, a room that's around 3x4.5m in size. Its warm and dry and a nice space, but it also ends up being a room for "we need to tidy up where can we put this". It's also next to my kids room so I basically can't get in there after 7pm. On top of that, this room and my 3x3m office are basically the home of all my tools. The plan is to house everything in the workshop and then just keep a tool tote in the house for the small jobs. That frees up 2 rooms in the house for more junk, ahem, useful things.

After reading the many threads and trying to pick up tips from them all in turn, I've been making models of the workshop in sketchup as much for something to do as for planning. This may transition to Fusion 360 depending on boredom levels with no work and time to kill. It may also make some aspects easier if changing the design.

Considerations

• Build it Mikes way
• Clay sub soil
• Slab will be 25m from the nearest point a truck can get to
• No building regs

Features

• pitched roof
• double door
• no windows (this could change)
• fully insulated
• plenty of power
• ethernet

Thread plan

• Initial plans
• you all explain why I'm wrong and or stupid
• updated plans
• detailed step by step on what I'll have to do/get and when
• many questions/suggestions
• mother of all cut lists and shopping lists
• many photos of it going wrong

Initial Plans
The garden currently features a tatty old shed that has many many holes in although oddly none in the roof! Weather, flora and fauna have all taken their toll and its time to get it cleared of my father in laws tat and get the site cleared. 2 Birch trees may need to be redistributed to either another part of the garden or the log pile. The wife wants them saved if possible.

The Workshop
I want to maximise the size before needing to adhere to building regs so will be staying under 30m2 internal. As I want to build over 2.5m in total height the workshop needs to be either 2m from any boundary or pass PP. Either are an option at this stage.

I'm looking at a pitched roof in the region of 30 degrees (7/12 pitch), a nice wide double door as the entry way in one of the gable end walls and at the moment no windows (I prefer controlled light, more wall space, less heat loss and less opportunity for thieving) however I may relent and put some in the long wall facing the garden with an internal shutter of some kind.

With a rough building length of 6.5m , the rafter ties (where used) will be placed as high as allowed to give me more head room while also offering some storage space. This will also reduce the size needed for the ridge beam as it won't have to span 6.5m but instead a shorter distance TBC. The main house also features this style of rafter ties and I wish when the extensions were done 30 years before we moved in they had done the same it really does make a room feel bigger! Alas flat roofs prevail.

Power and network will be trenched in (with a gap between them) approx 25m from the house with my electrician to give me the electricity cable spec. We could probably get away with 6mm 2 core SWA just fine but will most likely be 10mm 2 core SWA to keep the regs happy. We have a TT supply so a earth rod will have to be installed near the workshop negating the need for 3 core from the CU.

As much as I detest surface mounted electrics and wiring in conduit they do offer variability and ease of install. My guy is happy to leave me to the grunt work and to just turn up when the bits all need joining and testing.

Many sockets on walls and a few in the centre of the floor. Because sockets are life. Panel LED lighting throughout.

 

[DBT85]

The Floor
The workshop is going to have a concrete slab likely in the region of 200mm - 250mm thick. This is in part due to the close proximity of trees. I believe Mike suggested I put A142 mesh 50mm from the top and bottom. It is as yet unknown on how much hardcore will be required underneath. I have not yet dug an exploratory hole to see what I have under the grass. While I'm 100% certain its clay less than 15cm down, the bigger question is root systems from the adjacent trees. If this is the case then I could be looking at about 13 bags of type 1 and 7-8 cubes of concrete. The bags I can get lifted into the garden on some farm machinery, but the concrete will have to be lugged over, most likely in a dumper because pipper barrowing it all.

Since I won't be using it all day every day my plan is to not try and use the thermal mass of the slab. I'll insulate over it and then have a floating floor on top of the insulation. Were it to be used more regularly I might consider an insulated slab. PIR is something we have here in spades and can get readily for very reasonable prices. I can use that to also leave a small gap to run some sockets into the middle of the floor.

The walls
Walls to be constructed on 600 or 610 centres depending on the sheet goods from 100x50 treated timber. Single top plate as rafters will also be on the same spacing. Current plan calls for a big double door hole in one gable end wall and no window holes, but the latter might yet change. I shall annoy Mike by using the word header rather than lintel in the event that I do add windows.

Internally lined with 11mm OSB, filled with PIR board and sheathed in some kind of feather edge. Regular treated will of course be cheapest but if money were flush I might spring for something more exotic. Much like the roof options below, you're looking at 3x the price for Siberian Larch over regular treated wood. I don't know enough about whether you really can just leave Larch to do its thing (and so save on painting/maintenance) or not.

The roof
Also constructed on 600 or 610 centres this time from 150x50 treated timber on a 30 degree 7/12 pitch. Rafter ties to be used in places to add storage and reduce the size of ridge beam needed. Spanning 6.5m clear would need something substantial. I'm not sure how easy its going to be be to get hold of a beam that long even without it being that fat!

Like the walls, the internals would be lined in 11mm OSB so even if some scrote were to lift the tiles, progress is going to be hampered while also giving plenty of fixing space inside for things and stuffs.

Roof would be covered in either Onduline or a Decra/Metrotile type covering. The latter being about 3x the price of the former may force my hand. I'd rather spring for the better roof than the better wall cladding if I had to choose.

The contents
Right now the contents for this workshop are going to be an array of metal shelving units that currently live in my office, covered in various tools, paint, storage containers for plumbing/decorating/tiling/electrical paraphernalia, as well as the contents of my existing workshop. That comprises a English style workbench made to Paul Sellers design, and a custom MFT assembly table/wood storage unit not unlike the one that MacLellan uses (the Gosforth Handyman), just with more holes in. Also there is a very cheap Silverstone drill press, a Record Power BS250, an old Record Power DX4000 (it's blue it's that old!), a Triton spindle sander and a Record Power BDS150 belt/disk sander and a recently acquired (yesterday) Evolution table saw and Triton planer/thicknesser. Naturally in time I'd be swapping out some of those for more substantial units.

The Budget
I don't plan on starting this until I have funding in place. I really don't want it dragging out for months on end because I'm waiting for a little money to finish x or y.

If I were to go bare basics for the roof and walls I estimate I could get the whole project done for £5-6k. That's around £1400 for the base, £1300 for the timber, £1200 for the cladding and the rest taken care of in electrics, hire costs, dpm, dpc etc. As I mentioned earlier PIR board we have here in abundance and if I recall we last bought a load of about 30 50mm sheets for something like £130? I also have bricks a plenty so some saving is made there. I do also have a lot of clay roof tiles but many have seen attention from the frost monster. I'd rather not use them but they are an option.

So far the only quote I've had for concrete was 7m3 for £1280 :shock: Mostly because they only have 6m3 trucks and so I'd need 2 with one being mostly empty. I'll get a few more quotes I think!

I know that was a GWOT with not nearly enough pics, but they will follow I promise!

 

[Steliz]

Sounds like quite a project and I'm watching with interest but I would suggest that you use less homemade TLAs in your posts.

 

[DBT85]

Sounds like quite a project and I'm watching with interest but I would suggest that you use less homemade TLAs in your posts.

CIAWOYSW?

Can I ask which ones you struggled with? Or think others might? I don't think I've made any up and I literally had to look up what TLA meant haha.

I'm happy to change anything for clarity.

 

[MikeG.]

That all sounds OK to me, other than the concrete price. £120 ish per cube for that I reckon, although that might come down as building activity falls off a cliff.

The ridge beam doesn't need to be continuous, but we can look at details of that later.

 

[Steliz]

I reread your post and actually, there are only 2 I'm not familiar with. I didn't know what a TT supply was (thanks Google) and I couldn't work out GWOT either. Google says it's 'Global War On Terrorism'! Oh, and the one in your response so, that's three. No matter, life goes on.

 

[Fitzroy]

My 2p.

Go for planning then you can design what you want. Unless it’s outlandish or you’re in a beauty spot its surely worth the time/cost for the small risk of a refusal.

On a 25m run 10mm won’t cost you much more than 6mm. You’ll not regret the extra capacity but could if you expand your power use in the future.

No windows sound like an unpleasant place to be for hours, your site looks lovely is it’d be a shame to lose the connection with it as you’re making shavings.

My shed was clad in local larch and its weathering lovely. My reading was about a design that makes sure it can drain properly and is well ventilated with no spots that remain damp long term. I’m only 3 yrs in though so history will judge. Big overhangs are used on the continent in many of their timber buildings to protect walls and windows.

Not sure where you are with all this cheap PIR. In the past 3 years since our first building works and our last building works kingspan/celotex (think that’s PIR) has doubled in price. According to my builder who moans constantly about the price increases on it.

I’m planning on using rock wool R45 in the walls due to the sound absorbing properties, though a little less insulating, but I have closeish neighbours.

Beware these are just opinions of a rank amateur! Though your post was a great read, well thought out and sounds like super build that I look forward to seeing.


Fitz.

 

[lurker]

That looks a very rural site so I can’t see why you need to be two metres from the boundary.
You are not going to set the neighbours on fire if the shop burns.

 

[DBT85]

That all sounds OK to me, other than the concrete price. £120 ish per cube for that I reckon, although that might come down as building activity falls off a cliff.

The ridge beam doesn't need to be continuous, but we can look at details of that later.

Great, thanks Mike.

Out of interest. Is a rafter tie needed for every pair or is it every other or every third or something?

I reread your post and actually, there are only 2 I'm not familiar with. I didn't know what a TT supply was (thanks Google) and I couldn't work out GWOT either. Google says it's 'Global War On Terrorism'! Oh, and the one in your response so, that's three. No matter, life goes on.

Ahh. TT is just one of the 3 earth supply acronyms. I'd never ehard of it before about a week ago to be fair.

GWOT is Great Wall of Text. I'm certain I've not made that one up myself but perhaps I have. :lol:

 

[DBT85]

My 2p.

Go for planning then you can design what you want. Unless it’s outlandish or you’re in a beauty spot its surely worth the time/cost for the small risk of a refusal.

On a 25m run 10mm won’t cost you much more than 6mm. You’ll not regret the extra capacity but could if you expand your power use in the future.

No windows sound like an unpleasant place to be for hours, your site looks lovely is it’d be a shame to lose the connection with it as you’re making shavings.

My shed was clad in local larch and its weathering lovely. My reading was about a design that makes sure it can drain properly and is well ventilated with no spots that remain damp long term. I’m only 3 yrs in though so history will judge. Big overhangs are used on the continent in many of their timber buildings to protect walls and windows.

Not sure where you are with all this cheap PIR. In the past 3 years since our first building works and our last building works kingspan/celotex (think that’s PIR) has doubled in price. According to my builder who moans constantly about the price increases on it.

I’m planning on using rock wool R45 in the walls due to the sound absorbing properties, though a little less insulating, but I have closeish neighbours.

Beware these are just opinions of a rank amateur! Though your post was a great read, well thought out and sounds like super build that I look forward to seeing.

Fitz.

Thanks for the input Fitz.

I've been in 2 minds over the PP. On the one hand its just easy to do what I want and not have to faff with it. On the other hand with the shape of the garden and length of the workshop, to keep it all a minimum of 2m from the boundary would mean the far corner would actually be nearer 3m from the boundary. It then starts to get silly when you then add in overhangs and gutterings.

In addition, when I started to look at getting the plan the other day I noticed that the OS map of our property doesn't match what is actually here. The second extension was put on this house in 1985 (by the previous owners) and the OS maps don't show it. I don't know if it's relevant but it's one more thing I'd have to chase up and find out about. I'd not want to submit anything only for a visit to point out that I have a 70m2 extension on the back of the house that isn't on the OS map (but which definitely had permission).

In my current make-it-up-as-I-go plan the overhangs are 250mm on either side and 300mm out the back and 600mm out the front. As I said, I'm literally making it up as I go. I had an idea of having a kind of deck area under the roof (at a shallower angle) to tie the building into the garden a bit more. That corner of the garden also gets sun later in the day which might make it nice. Again its added cost and complexity.

I'm fairly certain that the sparks would only do the electrical run in 10mm at a minimum anyway. Its a case of "6mm is in reality perfectly fine, but to meet the regs it needs to be 6.2mm" or something daft.

The windows is one I've been thinking about and am still undecided. It's an added expense and I'm really not bothered about natural light (my job has required me to sit in an artificially lit box for 17 years now). But being able to see the kid playing and stuff would be nice.

The PIR has some from farmers sales. My Father in law trundles off to auction and comes back with piles of the stuff. The last load was £130 for I believe about 60 1200x600x50mm sheets. He was upset at paying the £130 as 2 months before he could have had some at £120. The farmer life!

This is most likely going to be a slow burner anyway so there's time to look at it all. With the announcement from Boris a couple of hours ago and the reality of things as they are, 2020 really would be a miracle for me to get this done. A real shame as in January it looked like I've have it up by September!

I thought for a horrible second that I'd just lost all of that and I didn't have the heart to write it again!

That looks a very rural site so I can’t see why you need to be two metres from the boundary.
You are not going to set the neighbours on fire if the shop burns.

It's exceedingly rural but the rules are the rules. In reality I could probably do whatever I wanted and nobody would ever be any the wiser. I'd rather not take the risk though so planning permission would be the only way. I'm sure it wouldn't be an issue to get though.

 

[Inspector]

How come you want treated wood for the wall timbers? I can understand on the sill in contact with the foundation but why the walls?

Pete

 

[MikeG.]

.......Out of interest. Is a rafter tie needed for every pair or is it every other or every third or something?......

The roof has to be looked at as a whole. The stiffness of the wall plate and the strength of the ridge beam come into the equation, as do the existence or otherwise of purlins. The point it, you can generally have widely spaced ties, or no ties at all, if that's what is designed in from the start. My suggestion is to say what you would ideally end up with and let's work backwards from there.

 

[MikeG.]

How come you want treated wood for the wall timbers? I can understand on the sill in contact with the foundation but why the walls?....

All constructional timber should be treated. In fact, it's hard to find non-treated construction timber these days in my experience.

The cill (we call it the sole plate) won't be in contact with the foundation. It will be on a plinth. I suspect from your question that you are American, where the foundation and plinth are cast as one. We don't do that.

 

[Inspector]

Canadian actually. Thanks for the answers.

Since we don't use treated wood in most cases above ground other than the sill/cill/sole plate, and not always on them, that's why my question.
I have a pressure treated wood foundation for the basement walk out house we have (builder talked us into it ) and the second level is all untreated. Outdoor structure like decks get the treated wood. In termite areas in the US they use treated wood for their houses. Too cold here for the little beasties. :wink:

Pete

 

[DBT85]

Had more prices for concrete but for different mixes.

One for Gen3 (C20 I think) from concrete2you/aggregate industries which was £107 per m3 inc VAT with only a 30 min wait time. Even with an extra hour wait added on its £990 for 8m3.

One for C30 from the concrete network which was £133 per m3 but with an hour wait time. Extra time is £2 per min plus a £45 admin charge plus vat. So its £1071 before any extra wait time.

Any direction on what kind of order I actually need?

I've even seen RC concrete for pours that have reinforcing mesh in.

 

[Steve Maskery]

My 2p having been down this road. In no particular order:

Floating floor works well. I can recommend Caberfloor as a top layer. Not much more expensive than chipboard, hard-wearing and doesn't need any finish on it.

Decide how many sockets you want and then double it. Really.

Insulate, insulate, insulate, especially if you are not going to have a proper heating system.

Mixing 8x4s with 2400x1200 leads to premature ageing.

I'm very glad I used Cemtiles on the roof. I say "I" but, you know.....

As well as power and data, consider also a water supply, even if it is only to an outside tap. A sink in the corner inside, though, is a luxury that I now would not want to be without. I have an instant-heat tap and it is brilliant.

I know that wall space is at a premium, but try to have at least one window.

If you go down the PP/Building Regs route, befriend your BCO early on. You want him with you, not against you. Mine was very helpful indeed.

If I think of anything else I'll add it.

 

[DomD]

Had more prices for concrete but for different mixes.

One for Gen3 (C20 I think) from concrete2you/aggregate industries which was £107 per m3 inc VAT with only a 30 min wait time. Even with an extra hour wait added on its £990 for 8m3.

One for C30 from the concrete network which was £133 per m3 but with an hour wait time. Extra time is £2 per min plus a £45 admin charge plus vat. So its £1071 before any extra wait time.

Any direction on what kind of order I actually need?

I've even seen RC concrete for pours that have reinforcing mesh in.

I paid £95 per m +VAT for C25; that was near London so prices may be less elsewhere.
To save on concrete I dug thickened edges to the subsoil (up to ~400mm deep) and then just had a 100-150mm main slab with mesh in it. I suspect because of clay heave you might want to have a thicker main slab though.
If you order volumentric concrete they will only mix as much as you need which definitely saved me money as my estimate was far off!
Good luck with your build,
Dom

 

[flying haggis]

+1 as steve says for a water supply even just for an outside tap. as you will have a trench open anyway, bung in a bit of blue pipe.

 

[MikeG.]

The problem with that is if you have a tap you need a drain. It isn't as simple as a bit of 25mm alkathene.....it's that plus 110mm surface water drain laid to falls.

 

[Steve Maskery]

Mike, can that not just go to the same (presumed) soakaway that the roof runoff is going to go to?