Correct foundation for a shed?

[JamiePattison]

We have an area of grass where we don't get a lot of sun and considering changing it to a hard floor such as slabs.

In order for the slabs to be stable, strong and not dip or sink in etc, what type of foundation mix would be required to ensure there are NO side effects later in the years of I use that space for heavy shed materials and tools?

 

[Jacob]

Depends on what the ground is like and the design of proposed shed.
Probably best to think slabs now as one thing, shed later as another.

 

[JamiePattison]

Depends on what the ground is like and the design of proposed shed.
Probably best to think slabs now as one thing, shed later as another.

The shed would be something from B&Q or some place like that. It wouldn't be fitted into the ground if that's what you mean?

 

[sawtooth-9]

Suggest you excavate the slab area and compact as best you can.
Lay builders plastic to prevent moisture from rising.
Lay and level the surrounding frame.
Put in a run of Rio ( you can get plastic "feet" to ensure the Rio is at a good height.
Pour the cement slab - 4 inch thick for light duty or 6 inch thick if the slab will have heavy machinery on it.
Also suggest you run some slotted drain pipe in any areas that might have water run off

 

[Spectric]

The shed would be something from B&Q or some place like that.

They are not sheds, they are just firewood made to look like a shed !

 

[Jameshow]

I would bed the slabs on a couple of inches of ballast.

So a bag might cover a 2x2ft slab.

Well compacted down with a manual wakee post or fence post will be fine.

 

[Bingy man]

Personally I would not go overboard as any base even a few slabs laid on a bed of sharp sand will probably outlast the b and q type sheds . The timber used to form the panels is cut so thin it twists and warps in a very short time allowing water ingress into the shed so unfortunately the shed will be attacked by the elements from inside and out .

 

[ian33a]

Ensure that the surface is stable and flat - ie. not sloping at all.

I'm in the process of laying a base for a garden shed at the moment. I have about three inches of compacted gravel. Then, on top, a square frame made from construction timber. Today, I've layed a concrete mix of 10mm gravel (2 parts), sharp sand (3 parts) and cement (1 part) to about 3 inches deep inside the CLS. Everything is levelled off against the CSL frame. I will leave it now for a week to dry. After that I will be building the shed on the base and will, afterwards, remove the CLS.

This is a shed to hold garden tools and a bit of light garden machinery - nothing especially heavy. The shed has it's own floor. It's from Tiger Sheds in Leeds and not from Guy Fawkes in Westminster.

Once finished I will add guttering and gravel around the periphery of the base. It's in a field, but I want it to look half decent even so.

As I have found previously, if the site isn't flat and level, the shed will be a pain to build and maintain. Also, if you plan on doing heavy work and having heavy machinery, I suggest you double the base thickness.

 

[mwinfrance]

I'm surprised no-one has mentioned re-enforcing the cement / concrete with a metal grid ( can't remember what you call it in english ) not quite rebar ( no "twist" ) but steel grid about 10cm squares of 8 or 10mm steel bar. I use it any time that the concrete slab is over 60mm.Especially if you are going to be putting any heavy machinery on it, without it the "slab" risks cracking.I even do that if I'm just going to be walking on it.

 

[benitod]

This post came in time to gather some hints for a shed construction for my son-in-law.
The steel that mwinfrance mentioned is called Truckson wire, here.

 

[Phil Pascoe]

Work out what you think is adequate and add 50%. You'll not get the chance to change your mind afterwards. Ensure you put ducts in for any future wiring.

 

[MikeJhn]

Just lay paving slabs on a sand and cement bed, nothing fancy needed for a flat area used for storage, if one sinks, just leaver it up and re-lay it.

Mesh reinforcing fabric in the UK comes in various size's, but overkill in this situation.