Concrete pools may suffer cracks or other damage over time due to improper installation or severe weather conditions. A damaged pool not only degrades the appearance of your property, but may even render the pool unusable due to leaks or structural concerns. If you spot a crack in your pool, repair it as soon as possible to minimize the long-term damage and to keep your pool operating throughout the hot summer months.
Remove loose stones and broken concrete from the crack by hand. Clean the crack with a wire brush to remove remaining dust or debris.
Apply epoxy adhesive to the suction cup-like ports on your concrete injection tool. Stick each port securely to the walls of your pool, centering them every 6 to 8 inches along the length of the crack. The ports must be centered along the width of the crack.
Coat the entire diameter of each port and the entire length of the crack with epoxy adhesive. Allow the epoxy to set and dry completely according to the instructions on the package.
Insert the tube of polyurethane concrete injection filler into the concrete injection tool. Depending on the type of filler you've chosen, you may have to attach two mixing tubes instead of one pre-mixed product. Slide the tubes into the tool, as you would load a caulk gun.
Place your concrete mixing tool on the pool deck above the crack. Fasten the injection tubing on the tool to the port that's situated lowest along the crack. Squeeze the trigger or handle on the tool gently until the filler begins to flow.
Watch the lowest injection port closely as polyurethane filler begins to flow through the tube and into the port. Hold down the handle on your injection tool to continue the flow until you see foam filler start to come out of the next highest port. Release the handle to stop the flow of filler.
Disconnect the filler tubing from the lowest port and attach it to the next highest port. Repeat these steps until filler starts to flow from the next highest port. Repeat this process to fill all ports, using the pressure gauge on your injection tool to guide you as you fill the top hole.
Place your injection tool on the pool deck, with all tubing disconnected from the ports. Allow the ports to dry in place with the filler, according to the directions on the filler tube.
Put on your safety glasses and dusk mask. Use a grinder to sand the ports and excess foam off the walls of the pool. Dispose of the ports and foam debris.
Apply plaster or paint to give your pool the desired finish.
If you plan to apply a plaster coating over the repaired area, use a concrete saw to cut a 1/4-inch deep joint along the length of the crack after you've repaired it. Clear out dust and debris, then follow the directions on the plaster packaging.
Use extreme caution when cutting or grinding concrete. Wear safety glasses to prevent debris from injuring your eyes.