How to Repair Leaks in Plumbing

Exposure to cold temperatures can cause plumbing leaks.

Leaks in plumbing, although potentially damaging if left unrepaired, are the one common household repair project that is manageable and easily corrected with a little DIY know-how. When looking for leaks, listen for sounds of dripping, pay attention to water pressure failures and learn to recognize the smell of mildew, which is caused by saturated materials that have begun to grow fungus. Leaks tend to occur around the places where pipes are joined or connected to fixtures, or where the plumbing has been exposed to cold temperatures. Prevent leaks by regularly inspecting plumbing and insulating pipes against the cold.

Things You'll Need

• Plumbing pipes
• Couplings, adapters and connectors
• Bucket
• Clean rag
• Pipe cutters or hacksaw
• Sandpaper or utility knife
• Lead-free flux and solder
• Applicator brushes
• Propane torches
• Plastic primer and glue
• Tape measure
• Plumber's tape

Instructions

Remove Leaky Coupling

1. Shut the water off to the leaking coupling. If there is no shut-off valve before the coupling, turn the water off at the main water line. Open faucets to allow trapped water to drain out.

2. Place a bucket under the leaking coupling to catch the water that will come out while you are cutting. Have a towel ready to wipe the water off the plumbing after you cut.

3. Cut out the leaking coupling with the pipe cutters. Keep your cut at least 6 inches long to allow room to install two new couplings and a pipe piece.

4. Allow the water to drain, and wipe the excess water from the pipe. Let the pipe sit for a few minutes undisturbed.

Install New Coupling and Pipe

1. Clean the existing pipes to create a good bonding surface. For copper, lightly sand the pipes and the inside of the new coupling with sandpaper. For plastic, remove any burrs with a utility knife, then coat the pipes and the coupling interior with plastic primer.

2. Attach the coupling to the pipe. For copper plumbing, brush the surfaces with flux and slip the coupling onto the pipe end. Use a propane torch to heat the pipe until the flux sputters and then touch the seams of the joint with solder, which will suck into the seam to seal it. For plastic plumbing, apply the plastic cement to the wet primer and insert the pipe end into the coupling with a slight twisting motion.

3. Repeat Step 2 to attach a coupling to the other pipe end. Measure the distance between the centers of the couplings to determine the length of pipe you need to complete the water path.

4. Cut a replacement pipe to fit the measurements. Sand the pipe and apply the flux for copper pieces. For plastic, remove any burrs, then apply a layer of primer and a layer of cement.

5. Push the prepared pipe into the couplings affixed to the existing pipe pieces. Heat the pipe and seal the seams with flux in the same manner as you used for the couplings. Use the same twisting motion for plastic pipes.

Tips & Warnings

• Take a sample of your existing plumbing with you to the hardware store to match pipe and fixture sizes and check for compatibility.

• The described directions were written to repair leaking couplings and adapters. However, the same processes can be used to repair pinhole leaks or cracked pipes as well as well as connecting new pipes to new threaded fixtures.

• When repairing threaded fixtures, it helps to wrap the threaded coupling with plumber's tape, attach the fitting first to the fixture and then attach the pipes to supply water to the fixture. This makes tightening threaded couplings or adapters easier.

• Copper plumbing requires an open flame from a propane torch to heat the plumbing. Use caution and watch for low-hanging fixtures, wires and other pipes to avoid a fire hazard.

• Some of the fumes from the primers and glues used for plastic pipes are strong and may irritate sensitive people. Wear protective clothing and ventilate the work area to prevent sickness or injury.

• Always check with local building codes first to determine the types of materials you can use to make repairs.

• Use lead-free flux and solder with copper plumbing.

• PVC, ABS and CPVC plastic pipes require specialized primers and glues for better bonding.

References

• The Family Handyman: How to Use CPVC Plastic Plumbing Pipe