I just got an interlocking backyard patio installed. The contractor was supposed to use polymeric sand, but I believe they lied and used regular sand and just told us it was polymeric. They didn't even spray the stone with water - I had to do it myself. Is there an easy way to tell without a doubt if it is really polymeric sand? There is also some left over in a container, if there is a way to test it using water or something. Thanks.
When this sand is wetted it will harden the same as mortar. Normal sand will not. It must be soaked several times (3) and left for 24 hours to harden correctly. Also there is about three quality levels and also you need to use the correct sizing for the joint size used. It is available in tan or grey.