My shed/summerhouse build will be around 3m by 4m give or take. if I build it with a single plane roof, or shed roof. Will this put considerable load on the lower wall holding up the roof. The shed will have treated wood base on concrete slabs. Will the structure hold up the roof and hold it all together? it will be 2.5m high, I'm just worried as it won't be dug into the ground so then I assume the structure will need to be self supporting. And I don't know how to be sure that it is.

Do i need to do anything to make it more solid, or will it be fine?

1 Answer 1


The roof loading transmits straight down, so the shorter wall and the taller wall will be bearing exactly the same roof load. Shed roofs can leave the structure a bit more prone to racking, which is basically the tendency of a square to deform into a trapezoid:

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You'll be fine if you do a couple of things. First, sheath the walls with 4' x 8' sheet material (i.e. OSB) and not long boards. This is the best anti-racking measure. Second, secure the bottom plate of your walls to the concrete slab with concrete anchors. The ones I like to use for existing concrete are wedge anchors or hammer-drive pin anchors. Finally, given your dimensions you will probably want to put in rafter ties that run level from the shorter wall to the taller wall to give a structural triangle:

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    I like comintern's answer. If you are going to pour the slab, the best way to attach the base is with bolts embedded in the concrete. If the concrete is already poured, you can use tapcon screws or powder-fired nails (tapcon are easier). If the shed is sheathed in panels (I used T-111 panels on mine), I don't think you need the rafter tie. Apr 14, 2014 at 4:52

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