Timber shed frame on top of paving slabs

sat_mad

Hi all,

I have recently ordered a new shed, which I'm planning to place on top of a paving slab base previously used for a greenhouse.

I have been getting the hard sell on an additional timber base for the shed to sit on.

Can anyone please advise whether it is really necessary?

I can see the advantage of maybe slightly better airflow and lifting the floor off the ground, but the paving slabs are pretty level (maybe 1 or 2mm difference between some of them) and presumably the base will rot (and spread to the shed) even if it's treated, with it being in constant contact with the ground.

clive0510

it will probably be ok on the slabs, providing they have a good solid base under them. would be better on a proper concrete hard standing, with a slight fall. the shed base they are offering will be on 2x2 timbers, and what happens is you lay that on your hardstanding, and because its got a fall, the rain water drains away between the 2x2s . what can also be done is to glue or tack some strips of plastic sheet to the bottom of the base timbers. that stops the damp from rising. 
so have a think about that, and wish you the best of british.

sat_mad

Ah, I see - that makes sense. Thank you Clive.

If it were needed I was going to construct it myself as the treated timber would be less than half the cost of the supplied base.

The plastic strips is a great idea. 

I will have a go and cut down some old DPC that I have. 

stuart45

You could run some brickwork as the bearers and put the DPC on top.
A course of bricks will lift it 3 inches off the ground, and won't rot.

sat_mad

Good point Stuart - thanks for the idea!