My Contract states in two places that to maintain my warranty on the Coping, Tile, and Pool Shell, I need to install an "isolation joint filled with 1/2 inch by 4 inch expansion joint material (i.e., ethafoam)" between the decking and the Coping. In another place it indicates I need to use "polysulfide or equal material."
My Contractor doing the decking thinks it is a bad idea to do this because it will look bad in a year or two and he doesn't think the foam can protect anything.
I'm having him do it to protect my warranty, but am curious what people think . Please note that my decking is the Techo Block INCA pavers (with no concrete base).