A bond beam is a thick layer of cement poured, or shot, on top fo the pool shell to bring the level of the pool wall up to the height of the landscape surrounding it. When a concrete, gunite or shotcrete, pool is installed, it is often a few inches below the level the unknown exact elevation. To bring the level of the pool wall to its final height, board forms are placed on top of the pool wall and concrete is poured to the desired level.
The place where the new concrete and old concrete meet is called a cold joint. This area is often right behind the tile line in an in-ground pool. It isn’t uncommon that the two areas of concrete will separate, but this is when you hear that a “leak is in the bond beam.”
When coping cracks, breaks or separates from the top of the bond beam, it can be a break or separation of the mortar that attached the coping to the bond beam. While fractures in the stone may be related to a vertical bond beam break below the coping, this isn’t always the case.