Like any material that's in constant contact with water's eroding force, you might occasionally have to replace your in-ground pool's coping. Coping is the lined edge around the circumference of your pool that prevents the water from spilling over onto the concrete or deck (unless someone does a cannonball).
Depending on when your pool was built, there are many possibilities as far as what materials were used. Many modern pools use a "bullnose" brick while others, such as vinyl lined pools, attach their coping to the wall. Depending on what kind of materials your pool uses for coping the repairs can be minor or expensive or require special equipment to fix. For instance, if your pool uses vinyl liner for the coping, the replacement tends towards the costlier side as the concrete deck is sometimes poured directly onto the coping. This article will discuss the most common coping repairs that happen when brick is used.
When water freezes it expands and this stresses the rigid materials, such as brick, that are used to contain it. This can loosen the mortar that attaches the coping to its foundation beam. Naturally your pool will expand and contract if you do not drain the water out entirely. If this is the case, your first step before doing any major replacement is to check if you've re-caulked the expansion joint recently. Small cracks are not problems and can be easily fixed. However, if a crack is large and enough water gets in, this can destroy a lot of pool foundations which require a costly outside solution.
When you have located the source of the issue, it's time to get down to the business of replacing the pool's coping. On average this can cost about $25 per linear foot. Bullnose brick can cost a bit more, and custom flagstone is even more expensive on top of that. First, gather your tools. You'll need a chisel and hammer and possibly a cut saw to help removed the loosened stone from the coping surround. You'll want to chip off any remaining mud, or dried mortar, from both the beam the brick rests on as well as the brick itself. Then you'll need to put it a new mortar bed. Use caution when handling the stone as they are fragile and can break easily. Make sure the new stone is level with the old, and then fill in the joints between stones with more mortar. If you are replacing the coping stone with a new one, keep in mind that sometimes due to fading the colors won't precisely match, even if they are technically the same color.
Lastly, a coping replacement that is going to be more costly is if your pool uses special Anthony stones. Because this brand of proprietary coping stones no longer manufactures them, solutions are rarely cheap and usually require professionals to come in and replace the entire coping surround. This can cost upwards of $10,000 for a full repair.