Shed/workshop compromises, please help!!

[yeungster79]

I was just working out my costs to-date, see my thread for details. Your timber costs are similar to mine (prorated for size) £1050 for 20x10 build. My costs are for 4x2 and 6x2 timber, so if yours are for 3x2cls they may be a little high.

F.

This is it having quick look around Edinburgh the mercants are taking the piss on the timber prices!

Saying that i need to get proper quotes direct from them.

 

[Freddyjersey2016]

Can I ask some questions
- If you are extending the house – are you doing it yourself or using builders?
- Are you digging foundations / laying concrete slabs for the extension - - by hand or using a minidigger?
- Does this new shed have to be complete before the extension starts? Could you shove some stuff into Storage for a few weeks


If other concrete slabs / foundations are being laid – laying a concrete slab for the shed would be quicker and much simpler than trying to accurately install 12 posts – in the right place and dead upright (I would not attempt to do this). The shed roofline is likely to end up higher to allow the thickness of floor joists/ airgap under… the floor – so then you need steps / ramp. Cast in a piece of 50mm plumbing pipe to get cable inside the shed.

If you go for a suspended wooden floor use 22mm chipboard flooring, much less likely to bend under load, and very little more expensive on this job. On a 2.4m span, I think you would need a mid-noggin to tie joists together to stop the floor bouncing (v. difficult to retrofit!)

Consider borrow / hire a compressed aiir or gas powered framing nailer – quicker than screwing / hand nailing. I would not bother getting timber cut at the merchants, get them to deliver in long lengths and gang cut to length on site when you know what you want

 

[yeungster79]

Can I ask some questions
- If you are extending the house – are you doing it yourself or using builders?
- Are you digging foundations / laying concrete slabs for the extension - - by hand or using a minidigger?
- Does this new shed have to be complete before the extension starts? Could you shove some stuff into Storage for a few weeks


If other concrete slabs / foundations are being laid – laying a concrete slab for the shed would be quicker and much simpler than trying to accurately install 12 posts – in the right place and dead upright (I would not attempt to do this). The shed roofline is likely to end up higher to allow the thickness of floor joists/ airgap under… the floor – so then you need steps / ramp. Cast in a piece of 50mm plumbing pipe to get cable inside the shed.

If you go for a suspended wooden floor use 22mm chipboard flooring, much less likely to bend under load, and very little more expensive on this job. On a 2.4m span, I think you would need a mid-noggin to tie joists together to stop the floor bouncing (v. difficult to retrofit!)

Consider borrow / hire a compressed aiir or gas powered framing nailer – quicker than screwing / hand nailing. I would not bother getting timber cut at the merchants, get them to deliver in long lengths and gang cut to length on site when you know what you want

No im not doing the extension myself have a builder doing it, we have a fair bit to store so im not so kean to store anything else where. I have about 4 months to build this, however it will consist of hours here and there. Once the extension build kicks off I don't really want to be trying to build my shed at same time, will be messy.

Ill defo go 22mm t5 chipboard for floor on 600mm joists. Im going to increase the width of it to 10 foot now, run a joist from end to end down the middle then the joists at 600mm will span less than 5 foot.

Nail gun would be needed, ill probably hire that.

 

[Halo Jones]

Just as a note. Height restrictions aren't as severe as they are in England. I posted the Scottish Guidance on a previous post https://www.ukworkshop.co.uk/forums/post1085687.html#p1085687.

Hope its useful.

H.

 

[yeungster79]

Progress made! Main floor frame almost built. Few hours digging out the 9 holes for 4'' posts. Half day to get the frame level and bolted to the posts and postcreted. Next job is the floor joists and then the T and G boards on top.

Some questions guys -

Should I lay polyethylene under the shed to stop any moisture coming from ground?

Also thinking about putting insulation between joists, thinking the stuff that goes in the attic will be cheap and do the job, any suggestions?

 

[pollys13]

Might be a bit late in the day, not read all the posts on your topic. Just a thought, I see where you are located, if you Goggle Edinburgh wood recycling.
You get quite a few links to 2nd hand timber might be other materials available too.

 

[yeungster79]

Cheers Polly, will have a look

 

[Fitzroy]

I did netting between joists and glass wool insulation in the nets, seems ok. Friend of mine keeps winding me up I've built a rat hotel though! So long as there is room/openness for a draft under the shed I doubt a polythene sheet would aid much.

F.

 

[yeungster79]

Contemplating doing similar Fitz regarding netting then laying insulation on top. Also contemplated using the plastic sheet instead of netting underneath stapled somehow to the floor joists to try keep out insects and rodents.. not sure if good idea??

Seen in your builld you mentioned you made an error bringing floor all the way to edge of floor frame effectively under the walls, is this just to allow easy removal of floor in future?

You finished your build now?

 

[Fitzroy]

From my reading unless you put metal rodent proof mesh then they will get in if they want too! Problem with poly sheet is it will not allow moisture to escape, if any gets in it will pool 'forever' if you see what I mean.

Regards the walls, another build on here did not take the Osb floor under the walls hence my statement of an error. I did some more reading but couldn't work out why it's a problem, except of course you can't lift the floor.

Im due an update to my build but been a busy end of year. All cladding is on, boy what a job, just sorting the door. Short days in Aberdeen don't allow much work at the mo.

F.

 

[Paul200]

Regards the walls, another build on here did not take the Osb floor under the walls hence my statement of an error. I did some more reading but couldn't work out why it's a problem, except of course you can't lift the floor.

I remember seeing this too and, like you, don't see why it's a problem. Certainly saves on doubling up the external base timbers. The only problem I had with it was that the floor has to go down before the walls and roof can make it watertight. Some moisture made it through the tarp I put over and the edges of the OSB3 swelled slightly. I guess the moral of the story is to make sure you can get the walls and roof up pretty damn quick! (hammer) (hammer)

Paul

 

[yeungster79]

Thanks Paul/Fitz.

As I need to do this in phases, I think probably best to add extra base timber to the floor frame, run the T+G floor up to the wall but not under. Then I'd have a solid base to frame the walls on, while not having the pressure to get the walls and roof up pronto, speaking of the roof, how flat can I go with EPDM?

If I went 1'' per foot over 10 feet, I'd be roughly at 6 degrees slope, is that OK fellas?

 

[Paul200]

Just had a quick Google and can't see that information anywhere quickly!? Give one of the manufacturers a ring. If it helps we've just had a zinc roof installed on our new kitchen extension and the minimum recommended slope for that was 3 degrees - so I would think that 6 degrees will be fine.

Paul

 

[yeungster79]

Found a great tool online http://www.blocklayer.com for rafters and birdsmouths etc, attached is the proposed rafter.

What's not clear in my head is the size required for roof rafters, the span is 10 feet, 1 foot overhang and 6'' at the low side.

Is it safe to span 10 feet with 4x2? I had a quick look and I see that C16 4x2 allows 8.85 feet, while C24 allows 9.51 feet, my roof will either be 11mm OSB or 18MM OSB with EPDM.

 

[yeungster79]

Right, reading more threads etc the walls will be 4x2 and the roof rafters 6x2 I think the extra expense is worth it long term.

One potential issue I have measured diagonal to diagonal and im off by 3/4'' from left to back right been longer. How significant is this?? Could I frame the walls slightly over the left post to ensure Im sqaure when walls go up??

 

[Phil Pascoe]

What a bloody amazing site! I'm going to poach it and post it in its own right.

 

[yeungster79]

What a bloody amazing site! I'm going to poach it and post it in its own right.

Blocklayer? Yea its supeb isn't it

 

[RobinBHM]

Thanks Paul/Fitz.

As I need to do this in phases, I think probably best to add extra base timber to the floor frame, run the T+G floor up to the wall but not under. Then I'd have a solid base to frame the walls on, while not having the pressure to get the walls and roof up pronto, speaking of the roof, how flat can I go with EPDM?

If I went 1'' per foot over 10 feet, I'd be roughly at 6 degrees slope, is that OK fellas?

Epdm is a flat roofing system. Generally felt flat roofs are set at minimum fall of 1 in 40 (1 in 80 is considered theoretical minimum for water run off, however 1 in 40 allows for felt joints etc).

On a 3.0m roof minium fall would be 75mm.

 

[AES]

Thanks to the OP for this link. As phil.p has said in today's post "something for everyone" here.

Most useful, (Imperial and Metric too!), bookmarked, thanks.

AES

 

[yeungster79]

Thanks Paul/Fitz.

As I need to do this in phases, I think probably best to add extra base timber to the floor frame, run the T+G floor up to the wall but not under. Then I'd have a solid base to frame the walls on, while not having the pressure to get the walls and roof up pronto, speaking of the roof, how flat can I go with EPDM?

If I went 1'' per foot over 10 feet, I'd be roughly at 6 degrees slope, is that OK fellas?

Epdm is a flat roofing system. Generally felt flat roofs are set at minimum fall of 1 in 40 (1 in 80 is considered theoretical minimum for water run off, however 1 in 40 allows for felt joints etc).

On a 3.0m roof minium fall would be 75mm.

Thx Robin, Ive tweaked the roof to around 12'' over 10 feet (1:12). Around 4.8 degrees of fall.