Paving Foundations

I want to replace the old worn out concrete paving slabs on my terrace with natural sandstone. It is for domestic use, no vehicles.

I am getting conflicting advice from contractors as to what is required in terms of foundations. The extremes are 75mm lean mix with 50mm mortar through to 100mm T1 plus 150mm concrete plus 75mm mortar. What is a reasonabe compromise? I am always nervous about concrete, a bit too permanent for my liking so would only want to use this if really necessary.

Existing slabs on sand/cement base and this will be removed (about 75mm thick as far as I can assess) with naturally compacted Essex clay soil underneath.

If its just for foot traffic, and has no other uses, laying the slabs over 4" of well-compacted hardcore and either a wet mortar bed or a compacted screed bed of sharp sand is fine.

Many thanks Wabbitpoo. That is line with the sort of thing I was anticipating but I am glad to have an independent view.

This is a great website to look at for paving.

http://www.pavingexpert.com/home.htm

Jono

WabbitPoo said:

If its just for foot traffic, and has no other uses, laying the slabs over 4" of well-compacted hardcore and either a wet mortar bed or a compacted screed bed of sharp sand is fine.

Click to expand...

I've just noticed it is natural stone, not concrete. In that case yo should use the wet mortar bed method. Some producers say to paint on the underneath of each slab with a cement/water slurry immediately before laying to improve adhesion.

Thanks again. I was going to use wet mortar anyway. Thanks also to Jono, an interesting site.