How much sand/cement do I need for shed base (slabs)?

[DIYNotIan]

Hi all

I've got a new shed coming next week. It's only a small one; 4' x 6'. I've never put one up before, so I've been reading up. I'm gonna use paving slabs for the base, and from what I've read it's a good idea to sit the slabs on a bed of sharp sand/cement (ratio 7 to 1).

What I'm not sure about is how much sand/cement I will need to buy. Can anyone help me out?

Also, any advice on how deep the bed of sand/cement should be would be very helpful.

As would any other words of wisdom....

Many thanks

Max

 

[skotl]

I put down 8 x 20KG bags of 10mm aggregate and then another 8 x 20KG bags of sand on top, for a shed of the same size. Total cost was around £35 from B&Q but you can probably get it cheaper from a builders' yard.

 

[r896neo]

For a 50mm deep bed.

10 x 25kg bags of sand

3 x 25kg bags of cement.

Any combination of sand and aggregate without cement is doomed to have a short life.

 

[DIYNotIan]

Many thanks for the replies. just thought I'd add a little more info.....

The sub base is quite level and solid. It was previously a shingled driveway. The shingle is gonna be removed, then I'll possibly skim some of the surface off so that once the sand/cement and slabs are in the surface level will be slightly higher than the surrounding.

So, if the sub is reasonable flat and solid to begin with will I need less sand/cement? Don't know, but for such a small shed (6x4) and I had no idea I would need so much!

Oh, and just for the record I'll be using 6 slabs in all, which measure 24" x 24".

Cheers

 

[Pigeon85]

Compact the ground as much as you can then just simply lay the slabs on a bed of mortar, alternative suggestion would be to use sharpe sand to level the ground out but it will over time become unlevel, a lot of slabs get put down like this, some last for years and some last only a few months so it does become a gamble

 

[r896neo]

Anything under 25mm deep is un-workable because there is so little give that tapping them down level is impossible.

2 bags of cement and 8 bags of sand would probably do you.

You'd be surprised at how much you'll use. A 600x600 flag will take almost 1/2 a barrow of mortar.

 

[DIYNotIan]

Just got the slabs. There are VERY heavy concrete type!

I'm just curious to know what would happen if I did not put sand/cement down first? Not saying I won't, just curious....

 

[r896neo]

They will rock about and start cracking and will simple get worse and worse.

That said it will probably last a couple of years but then you'll have to dismantle and move your shed to sort them out and will damage your shed in the process and cost yourself the time and money to do it right when you could just do it right now.

Pressed concrete 2x2's are a 2 man laying job unless your very strong and used to doing it.