help with my new shed build

[shim20]

i want to build a new shed/workshop, hopefully 10ftx8ft but i want to make it a prefab type one that can be taken apart in sections, so make the floor and the 10ft wall bolt together in 2 parts, im after some advice on what size timbers i could get away with 2x4 might be a bit mighty? thinking maybe 3x1 if there is such a thing, then i was going to nail the shiplap boards on the frame which should make it strong, also the roof what would be the cheapest way to do that, thanks for any input
ben

 

[condeesteso]

Hi Ben - been there before - and it's a good plan to build from scratch yourself. Personally I would definitely use 3x2 carcase timber - the yards call it C16 (C24 is the tested higher grade but C16 will be totally fine. I suggest this because it is cheap (3 x 1 isn't so standard for framing, so is probably more expensive. 3 x 2 will more than do what you want. Shiplap is v good as it seals nicely (F'edge obviously doesn't). I did mine using shiplap, bonded with polyurethane (Screwfix, cheap, sticks like a sod... the one that foams a little as it goes off). Also I screw as nails shake the structure too much, and these days screws are as cheap (Screwfix again). Joints for the frame are half-lap, poly and a screw again.
Make sure the floor is breathing underneath (a few inches clearance) and lay any old membrane under - to inhibit weeds etc and create a damp barrier. Best lay DPM under everything (v cheap again) and place bearers on top of that. This is all in the pursuit of DRY... it is quite hard to keep moisture out, so you need all the tricks you can get.
For the roof, I would keep it light, look for low-grade shuttering ply etc, and felt it. Plus make sure any rainfall sheds away from the structure - just making the eaves overhang a bit more helps (say 10") and a French drain is great (it's just a small trench around the building, about 9" deep, fill with gravel or hardcore, and it acts like a mini soakaway.

Hope that helps a bit...

 

[shim20]

thanks yer thats a great help, i was thinking for security reasons of having no windows but a clear roof, what your thougths on this?

 

[MickCheese]

thanks yer thats a great help, i was thinking for security reasons of having no windows but a clear roof, what your thougths on this?

Claustrophobic!

Mick

 

[shim20]

yer will be wont it, might make some sutters that lock for the window then?

 

[condeesteso]

sorry, couple more thoughts... make the roof using quite thin shuttering ply (find whatever is cheapest), but in 2 layers, with any old 1" batten between (tiling batten is v cheap and tannelised). The air gap will be good (insulation and damp) or put any insulation in the gap... even bubblewrap, shredded newspaper...! And leave an air gap in the cavity. The roof carries no load so thin sheet is fine.
For the walls consider cladding the 3x2 frame with roofing membrane before fixing the shiplap (by roofing membrane I mean the damp membrane that goes under the battens before tiling). You then have the option of skinning the inside face and again the gap is damp-proofing and insulation.
My obsession with damp and insulation is from years of fighting moisture in workshops - I have never seen, heard of, or had - a workshop that was too dry (certainly not in our latitudes).
And then it gets cold - for say 5 months of the year. So make it warm if you can!

 

[shim20]

thanks will do that any info is always good