Foundations for a shed,2m by 2.5m

Question

I am moving my shed and having dug the area level i am wondering what is the best foundation for it to sit on.Should i completely slab the area on a bed of sand,do the 4 corners only.............?

Answer 1

I have always found paving slabs make an ideal level base for sheds, they are not expensive, easy to lay & can easily be removed later if required, they help to distribute any load placed in the shed without distorting the shed itself, they also prevent weed growth, damp dirt collection which over time will rot the wood, it gives vermin nowhere to hide, etc. altogether making a much better job by preventing these things

Answer 2

sheds are very lightweight buildings so normal earth or sand is ok. A plastic  sheet may help stop the rot.  

Answer 3

Yep,no need to be anal about this by putting tons of concrete down.The easiest way is to put about 3 inches of gravel across the area.Rake roughly level and place the shed on that.The gravel will keep the bottom dry and no complax levelling involved.But put a decent amount down.Otherwises sand and 3x3 fence posts put down on the sand.About 4 should be enough and place onto posts.Otherwises 4 heavy paving slabs,laid on sand at each corner.

Never make a concrete base,as removing it is expensive and difficult as well as pricey installation.The above types are flexilble if you want to move the shed again ,years later,and if it become uneven you can re-lel the base

Answer 4

I think that your best solution would be to mix up a weak sharp sand and cement base for the paving slabs (5 parts sand to 1 part cement) to lay on and slab the whole area. This will give a great base for the shed and also give a stable solid interior floor.

Answer 5

Build it on stilts, 4x4 inch fence posts, set in concrete, 18 inches below ground and 8 inches above.This will stop the base rotting.

Answer 6

If the shed is timber the floor joists probably span across the short direction(2m). This is quite large as sheds sometimes have quite small timbers and any heavy weights in the middle of the floor will cause a bit of deflection. A timber floor should also have some ventilation beneath it to prevent stagnant air and fungal decay. Thirdly it should be clear of the ground to keep the timber out of the damp soil and also don,t forget that an empty shed can blow over in high winds.

Minimum I suggest is heavy concrete blocks(300x100x440mm), at the 4 corners and mid-way along all walls (ie. 8 in total), with some kind of rawl bolted or screwed connection of a galvanised strap at each to hold it down. You may want to put an extra block centrally beneath the floor and a treated timber or concrete lintol 2.5m long up the length to suport the middle of the joists - this may be optional but get into the shed and feel the bounce. Watch the levels here as this row should be set lower to allow for the centre support timber. Allow a small clearance above the ground for ventilation and place polythene or damp proof course between the block and shed timber. The blocks can be levelled for now using sand but you may in future years have to jack the shed up a bit and raise any bit that sinks - this depends on the soil below - remove topsoil or soft material at each block.