Thawing frozen pipes is a time-consuming process. Water expands as it freezes, so frozen pipes or joints may burst or leak. For this reason, in cold climates, water-supply pipes are rarely installed in exterior walls or other unheated areas. Thaw pipes, heat or insulate problem spots and make repairs using one of the following methods.
Heat the wall cavity containing pipes by adding return-air grills near area where drain comes out of wall. Slide 1-in. (2.5-cm) piece of rigid foam behind pipes for further protection. If possi ble, add second grill to cabinet side to let more heat in.
Wrap heat tape around pipes and secure in place with tape. Use tape that's controlled with a built-in thermostat.
Thawing Pipes
Before thawing a frozen pipe, close shutoff valve or main water valve. Open faucet to allow melting ice to run out and let steam pressure escape -- this is especially important if you use a propane torch on metal pipes. Work from the faucet toward the frozen area. As ice melts, check for leaks and take note of any you find.
For plastic pipe, heat using a hair dryer or heat lamp. Keep the heat source moving; the pipe must remain cool enough to touch. Work from faucet to frozen area.
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Wrap rags around metal pipe and pour boiling water over the rags. When the rags cool, repeat the process. You can also wrap a grounded, waterproof heating pad around pipe.
Pipe Insulation
Wraparound foam pipe insulation is available in several sizes. It will help maintain the temperature of water in the pipes, but it won't protect pipes in areas prone to long-term freezing. The insulation is split to allow it to slip over the pipe and cuts easily with a serrated knife. The insulation also keeps warm, humid air from condensing on pipes, stopping the pipes from sweating in the summer.
Quick Fix for Holes
The best way to deal with a hole in plumbing is to replace the section of pipe, but a temporary fix helps you deal with emergency leaks. First, shut off the water supply. Next, slit a section of hose or a rubber couple available at hardware stores, and place it over the hole. Finally, secure the rubber patch with hose clamps. Larger holes will require multiple clamps placed side by side.
