Several type of thin stone tiles are very susceptible to warping. Many of the green marbles and a few agglomerate marbles are notorious for this warping condition. Many of an installer have had the surprise to find that there tile installation has become warped overnight.

Why does this a happen and can it be prevented?

Warping is caused by water. Green marble set with any water based material will have a tendency to warp. The mechanism of why the tile warps is somewhat a mystery. Some believe that the water fills the pores of the stone and when the water evaporates the orientation of the stones crystal change and cause it to warp. Whatever the reason, one thing is for sure, green marble can warp when set with water based materials.

Cure: Once a green marble tile warps it is difficult to repair. Attempts have been made to grind the tile flat , but this usually fails since additional water is introduced during the grinding process. The green simply warps again.

Prevention; The only way to prevent warping is to install it properly with a non-water based material such as epoxy. Some installers have also been successful in sealing the back of the tile with epoxy and installing it in a water based system. Do not attempt to seal the back of the tile with a silicone sealer. The silicone acts as a water repellant and will cause the setting material to fail resulting in a bond loss.