Laying Patio Slabs on Uneven Concrete Base

GMDIY

Hi All,

I would like to lay paving slabs to renovate my back garden. My issue is with the base I will be laying it on. It is an uneven concrete base.

My plan is to have a mix of sharp sand and cement in an 8:1 ratio. I will then even the surface out with this mix, is this acceptable? Or would you advise using a sub base to even it out first?

Any help or advise would be much appreciated!

bris

What height will the sharp sand be? Spread the sharp sand to 25 to 40 mm and compact it down and it will find it's own levels and fill the gaps. The concrete already makes a good sub base.

GMDIY

Thanks for the reply. I will go ahead with the original plan of just using he mix to level out the base. Does it matter if you go over 40mm of sand in certain areas, to bring it to the correct height?

stuart45

It's OK to go over 40mm in places. A lot of people mix 50/50 sharp/ building sand to make it easier to use.