Your in-ground swimming pool may need repair work from time to time. One area that you may be able to repair as a do-it-yourself project is the pool coping. This is the lip of the pool that runs from the expansion joint on the pool deck to the edge of the pool and then down the side to the water level. Sometimes tiles or individual pieces of bull-nose edging come loose and you can repair pool coping with some grout. In other instances you may need to pour concrete to fix the problem.
Investigate the cause of the damage to the pool coping in the first place. If you don't fix the cause of the problem, it can cause more problems in the future. Common causes are water getting in around an improperly sealed expansion joint or improperly mixed mortar used to set bull-nose edging.
Assess the extent of the damage. Determine if the swimming pool needs repairs on the top side of the coping or if the damage extends to the sides. Decide if you can do the repair work with water in the pool or if you need to at least partially drain the swimming pool to repair pool coping.
Put on your safety goggles. Remove the loose and damaged section of pool coping. You must remove any debris that falls into the pool and not allow it to go down the drain, whether there's water in the pool or not. If the pool has a precast coping or bull-nose coping, you should be able to pull up the damaged pieces without further damage. If the pool has flagstone or manufactured stone coping, handle with care as these pieces are a bit thinner than precast coping. If your pool has poured concrete or a cantilevered coping, you may want to call a professional to repair pool coping.
Use a cement cut saw to make a straight edge on the damaged coping if necessary. Remove all dust and debris from the area where you are replacing the coping.
Clean the old mortar off the coping you removed earlier. If you can't reuse those pieces, find replacement pieces to match your existing coping.
Mix up enough thinset mortar mix according to package directions to set your coping pieces. Put mix on the opening on the pool wall as well as on the back of the coping pieces. Set each piece in place. Allow the thinset to dry. Depending on the original installation process, you may need to put mortar between pieces as well and allow it to dry.
Caulk the expansion joint to complete the swimming pool coping repair.
Water and electricity don't mix. Be careful when using any electrical power tools around the swimming pool.