shed base

[fred]

Putting in a concrete floor for a small shed (4m x 4m). This obviously involvee removing soil and if I go down 150mm this would give 2.4m3 of waste to dispose of, which might present a problem.Question is what is the minimum depth I can get away with if I am happy to have the slab protruding above the surface? This shed is just to allow me store a small 2mx1.2m trailer and a small ride on mower trailer. I might want to put a few small machines in it also to free up space in the other two sheds. I think I would chance a 50mm slab as the usage will be light so what base would I need and how deep to dig ?

[alan_m]

Consider also something like

if the concrete is not being used as the floor.

Friends of mine used this method for a large shed they had installed over a year ago and it appeared to have worked extremely well.

[The Natural Philosopher]

You don't have to dig at all. I put in about a 3" slab just on top of a rough gravel and MOT drive. The main point of digging is to get a level and compacted base. But you don't need the former - it just increases the quantity of concrete you need - and just scraping any loose soil off will achieve the latter. Especially if you pop some rebar or chicken wire in.

[alan_m]

An alternative method of installing without having to remove a 2.4m3 of waste

[Fredxx]

I see no reason why the concrete base should not protrude above ground level if being used as the floor. It would help keep water out for one.

[nightjar]

For all my sheds, I simply levelled and compacted the soil then put the slab on top of that. The garden has been known to flood and that keeps the floor of the sheds above the highest known flood level.

[Chris Green]

We have a 6m x 5m cabin simply sitting on a frame which in turn rests on a dozen or so half-metre square concrete slabs, it's been there for a couple of years now and hasn't moved at all. We didn't d-i-y this, it was done by an experienced and well recommended 'cabin erector'.

[Jim GM4DHJ ...]

just go down through the vegetable soil a raft slab doesn't need to be deep for frost protection.....

[fred]

Many thanks to all.This is the third she?d build. They fill up so quick. The first one has a chipboard floor on joists on small concrete pads. Still sound as a bell but it needed a ramp to get the ride on in. Second one has a concrete floor and is thus at ground level. Can?t remember what depth we set the slab but concrete is not my forte so it can?t have been that deep. This third she?d promises to be the biggest so the problem with removing large quantities of soil is raising its head. I think I?ll just go down a few inches and set the former there. The ground is very firm so I?ll just pour the concrete in. About three inches I suppose