I have a client who is has an older inground pool that is causing some problems. Should the concrete around the pool be level with the coping or sloped out? How well does the the concrete have to be sealed to the coping? Currently there is 1-1/2" gap between the concrete and the coping that is sealed with clear silicone caulking. How do you keep the concrete from shifting do to freeze and thaw? The tile around the top edge of the pool is poping off and the coping has a hollow sound when you tap it. Any comments or suggestions will be greatly appreciated.