Slabbing on top of Slabs/concrete

[beenz69er]

Hello people. I am intending to lay a natural stone slab over the top of a grey council slab. The slabs are unlevel but i can sort that out with the mortar base. Can i do this and is it best to spot the new slabs with the mortar or use a full mortar base considering the sub base? In the past i have used a fairly dry mix for laying slabs but have recently been told to use a wet mix for laying slabs. The new slabs are between 18mm and 34mm thick and i have about 7.5 inches to the damp course. Any advice/help would be appreciated .

 

[Thermo]

on the assumption that they are sound and there is no movement then you could lay them on a wet full mortar bed

 

[beenz69er]

There is definitely no movement (twenty odd years of being ignored) and the concrete sections in between the slabs can ensure this. Is it 4 to 1 for the mix and can i use building sand as i have a massive abundance of this?

 

[WabbitPoo]

Get some sharp sand and use a combo - gives the mortar more crack resistance. Follow the wealth of other advice often given on here too regarding laying stone slabs.

 

[Thermo]

personally i always use building sand for laying. personal choice, everyone differs on here!