Building 700 sq ft granite patio in Connecticut. Wet or dry set?

[Dmitry]

I want to built 700 sq ft granit patio using 2' by by 3' one inch thick granite slabs.Two thirds of the area has existing concrete over it . 40 years old but holding with some cracks .
Should I just remove concrete it and lay stone over aggregate and sand or pour more concrete and mortar all the stone.
The concern with wet ( mortar ) set is that it might crack after some times due to our thaw/ freeze circles.
Any knowledgeable advise?
I've done a lot of research but wondering if some had expirience with it,

 

[gzecc]

Can you lay on top of the old concrete? If it is graded ok you can add paver base to it and lay the new stuff directly over it. I also vote for dry install. Make sure it has a great base and great perimeter retention.

 

[Dmitry]

Thanks for your replay. That's what I want to do. The existing slab is sloped away from house . Every contractor said I need to put it on cement , don't see why I couldn't just ad sand and stone dust and lay on it

 

[gzecc]

Thanks for your replay. That's what I want to do. The existing slab is sloped away from house . Every contractor said I need to put it on cement , don't see why I couldn't just ad sand and stone dust and lay on it

Sure you can, if your existing slab is smaller than the new design you will have settling issues. If its the same size it will work nicely

 

[johneh]

Is the slab covered ?
If there isn't a roof over it rain water will wash the sand and dust out
from under it as the water has no place to go . That's why the contractors
want it set in concrete