Cause of Bond Beam Cracks
Concrete andExpansion and Contraction in Concrete Construction
Materials expand and contract with temperature. Concrete and mortars are no exception. A swimming pool deck can reach temperatures in excess of 135 degrees in the summer, and as low as 30 degrees in the winter. A 100 foot section of concrete will expand 3/4 of an inch with this more than 100 degree swing. This is an incredible amount of force that can push on the pool coping, and bond beam, creating a crack, and loose/missing tiles. Without a properly installed expansion joint, this can result in leaks
Cantilever Concrete Deck
A cantilever deck is one that extends from the deck over the bond beam with no expansion joint. Cantilevered concrete pool decking must be properly installed to isolate concrete deck from the bond beam. The proper construction technique requires the installation of a bond breaker or slip joint on top of the leveled beam prior to pouring the concrete deck. By not following the proper construction techniques, the waterline tile may become partially applied to the cantilevered deck which will result in horizontal cracks in the tile. The cantilevered concrete deck should have no direct contact with the bond beam of the pool especially immediately behind the bond beam.