how high to go with sub base for patio

thebackbar

Hello,
im planning in bringing in a contractor to lay a kilkenny limestone patio for me.
I was wondering how high should i bring the sub base of the patio up so that the contractor can come along and do their bit of laying the patio ? im trying to have it all ready for them.

my3cents

You don't know until you have dug all the garden soil out and got down to subsoil. Replace with clause 804 stone (any supplier will know the term) leaving enough room for a bed for the slabs and the slabs themselves.

Anything that has humus in it will eventually shrink as the humus rots away so you need to remove all the brown looking soil down to the subsoil which might be anything from yellow clay to chalk or even builders rubble.

We could debate the merits of 803, 804 and even 3 inch sub grade all day but tbh any of them will do the job.

thebackbar

thanks, im hoping to bring it up to the height with clause 804 alright, but what room should i leave for a bed for the slabs and the slabs themselves ?

my3cents

thebackbar wrote: »

thanks, im hoping to bring it up to the height with clause 804 alright, but what room should i leave for a bed for the slabs and the slabs themselves ?

Ask the guy laying them. It really depends how they are doing it?

Some spot bed but at the other extreme I've laid on dry sand cement mix over poured concrete.

If you can level out your 804 then you don't want to allow anymore than slab thickness plus an inch probably less.