What do you do with the DPM in a concrete shed base?
Discussion
I want to build a concrete base for a garden shed, size approx 5m x 3.5m (16'6 x 11'6). The shed will it on timber beams, and have an insulated wood floor, so no standing (or seeing) directly the concrete base.
From reading up in numerous places on the web, it seems that I can get away with digging a 10cm deep hole in my garden (turf) and pouring in concrete and tamp it down. This leaves me with a concrete base level with the garden, which is what I need rather than a raised base. I'm trying to avoid the time/hassle/cost of laying subbase first, as I reckon my ground is solid enough, and ultimately there will be no heavy weights on the base.
Many places also recommend laying a DPM. This is fine, but what I dont understand is that if I lay a DPM sheet, then it will fold up the sides of the concrete and stick up in the air. Presumably then any rain/water can just run down the side and ultimately pool between the DPM and the concrete slab. This surely defeats the point of the DPM?
How do you "finish" the DPM edge?
From reading up in numerous places on the web, it seems that I can get away with digging a 10cm deep hole in my garden (turf) and pouring in concrete and tamp it down. This leaves me with a concrete base level with the garden, which is what I need rather than a raised base. I'm trying to avoid the time/hassle/cost of laying subbase first, as I reckon my ground is solid enough, and ultimately there will be no heavy weights on the base.
Many places also recommend laying a DPM. This is fine, but what I dont understand is that if I lay a DPM sheet, then it will fold up the sides of the concrete and stick up in the air. Presumably then any rain/water can just run down the side and ultimately pool between the DPM and the concrete slab. This surely defeats the point of the DPM?
How do you "finish" the DPM edge?
Renovation said:
If you're not using the concrete as the floor - why bother with it at all ?
All my sheds have had timber battens either directly on the ground or on slabs / blocks simply placed on the topsoil.
No issues after 5-8yrs
Dunno really. Everywhere seems to tell you to lay concrete base.All my sheds have had timber battens either directly on the ground or on slabs / blocks simply placed on the topsoil.
No issues after 5-8yrs
I didnt "want" to use concrete, I just thought it was what I was meant to do.
So I looked into timber frames, and it looks sensible enough. I'm keen to maintain extra height over the topsoil though, as I'm looking at fitting celotex insulation foam between the floor joists, so need to raise the joists to get extra room for airflow over a wet soil base.
I noticed that there seems to be this option on the market, which involves putting a timber frame on adjustable supports/feet:
Anyone used this? Its quite cheap (if you buy it direct, not from the shed retailers), and would be an easy answer to ensuring a perfectly level base on which to build the logcabin.
Maybe actually I put the logcabin floor joists directly onto these feet, and not double up with a separate frame underneath.
So I looked into timber frames, and it looks sensible enough. I'm keen to maintain extra height over the topsoil though, as I'm looking at fitting celotex insulation foam between the floor joists, so need to raise the joists to get extra room for airflow over a wet soil base.
I noticed that there seems to be this option on the market, which involves putting a timber frame on adjustable supports/feet:
Anyone used this? Its quite cheap (if you buy it direct, not from the shed retailers), and would be an easy answer to ensuring a perfectly level base on which to build the logcabin.
Maybe actually I put the logcabin floor joists directly onto these feet, and not double up with a separate frame underneath.
Edited by kryten22uk on Thursday 26th March 08:52
ILoveMondeo said:
Oooh that looks easy..
Any links to a supplier?
There are loads of suppliers - just search "adjustable timber decking support". They only cost about £3 per foot. You can sit the feet on anything really, either directly on soil, on hardcore, on individual slabs or individual plastic mesh squares like in the picture. The benefit is that you dont need to prepare the whole base area, only the square on which the feet will sit.Any links to a supplier?
That picture is actually from DunsterHouse, who want £500 for the footing solution!
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