Foundation for patio slabs


Postby jlc » Sun May 01, 2011 8:20 pm

Hi

I have a small back garden, mostly covered in patio slabs. A few have sunk a bit and become uneven and I want to level them off so my son doesn't trip on them. Is it OK just to put sand down or should I try sand and cement? Never done this before as you can probably guess!

John
jlc
Posts: 16
Joined: Mon Dec 29, 2008 6:19 pm

Sponsor

Simply Build It

Postby stoneyboy » Sun May 01, 2011 10:54 pm

jlc,
Just use sharps sand, you can then re-level as needed.
end
stoneyboy
Posts: 2708
Joined: Wed Dec 10, 2008 6:44 pm


Postby MickBee » Wed May 04, 2011 2:00 pm

stoneyboy wrote:jlc,
Just use sharps sand, you can then re-level as needed.
end
The implication behind this advice is that if you only use sand, you will need to re-level from time to time.

On the other hand, if you want to do the job only once, an alternative way is to:
(1) make sure that the subsoil is firm (jump up & down on it)
(2) put down a bed of sand approx 1" / 25 cm thick, & level it to a depth below the slab-top of (25 cm + the slab thickness)
(3) put on a 25cm layer of sand & cement (for a small number of slabs, Lafarge Slablayer is simpler to use & not too much dearer.)
(4) Water the underside of the slab, and ideally coat it with Waterproof PVA adhesive
(5) Water the sand-cement mix thoroughly, and lay the slab.

When you have re-laid all the uneven slabs, don't forget to point between the slabs with a cement-mortar mix - for this too, it is better to prime the edges with Waterproof PVA adhesive.
MickBee
Posts: 4
Joined: Sun May 16, 2010 6:10 pm


Display posts from previous
Sort by
Order by


 


  • Related Topics