Recently had my garden renovated, and part of it which was flagged with 22mm sandstone slabs is very hollow. They were put down on a screed mix and jointed with joint it. They do look excellent and the garden does look amazing. But worried the fact that most of the slabs are hollow when you tap them...
Most likely not laid on a full bed of mortar,as they should be,but only spotted,(spot bedding), a dollop at each corner & one in centre. http://www.pavingexpert.com/stain_reflective_01.htm
What are my options, should I be worried the slabs will weaken and joint it will crack. The bill has yet to be paid as it only arrived
Better to have been laid on a full bed but there must be thousands of areas which were spot bedded when they were put down. Indeed done it myself where the slabs are old and hard or thicker than the lightweight ones available. I wouldnt worry at all if you can put up with the hollow sounding when walked upon.
I'm not an expert by any stretch but isn't 22mm for a slab thickness on the weak side to start, especially being sandstone and by the sounds lacking a full compo bed?