Joints that are made of mortar or concrete at the base make it necessary to create an expansion joint when laying the tiles. These moving joints require ultra-elastic materials to absorb the enormous stresses of dilating-expanding that the tiles must withstand.

The waterproofing of a pool will depend on the concrete basin: an exposed concrete basin MUST NOT let the water through. The best and most economical option to achieve this is to use a hydro expansion joint to automatically block the water channels, if these should form.