Water has a unique property in that it expands as it freezes. This expansion puts tremendous pressure on whatever is containing it, including metal or plastic pipes. No matter the "strength" of a container, expanding water can cause pipes to break. Pipes that freeze most frequently are those that are exposed to severe cold, like outdoor hose bibs, swimming pool supply lines, water sprinkler lines, and water supply pipes in unheated interior areas like basements and crawl spaces, attics, garages, or kitchen cabinets. Pipes that run against exterior walls that have little or no insulation are also subject to freezing.
Preventing Frozen Pipes
Before the onset of cold weather, prevent freezing of these water supply lines and pipes by following these recommendations:
- Drain water from swimming pool and water sprinkler supply lines following manufacturer's or installer's directions. Do not put antifreeze in these lines unless directed. Antifreeze is environmentally harmful, and is dangerous to humans, pets, wildlife, and landscaping.
- Remove, drain, and store hoses used outdoors. Close inside valves supplying outdoor hose bibs. Open the outside hose bibs to allow water to drain. Keep the outside valve open so that any water remaining in the pipe can expand without causing the pipe to break.
- Check around the home for other areas where water supply lines are located in unheated areas. Look in the basement, crawl space, attic, garage, and under kitchen and bathroom cabinets. Both hot and cold water pipes in these areas should be insulated.
- Consider installing specific products made to insulate water pipes like a "pipe sleeve" or installing UL-listed "heat tape," "heat cable," or similar materials on exposed water pipes. Newspaper can provide some degree of insulation and protection to exposed pipes – even ¼” of newspaper can provide significant protection in areas that usually do not have frequent or prolonged temperatures below freezing.
- Keep garage doors closed if there are water supply lines in the garage.
- Open kitchen and bathroom cabinet doors to allow warmer air to circulate around the plumbing. Be sure to move any harmful cleaners and household chemicals up out of the reach of children.
- When the weather is very cold outside, let the cold water drip from the faucet served by exposed pipes. Running water through the pipe - even at a trickle - helps prevent pipes from freezing.
- Keep the thermostat set to the same temperature both during the day and at night. By temporarily suspending the use of lower nighttime temperatures, you may incur a higher heating bill, but you can prevent a much more costly repair job if pipes freeze and burst.
- If you will be going away during cold weather, leave the heat on in your home, set to a temperature no lower than 55° F.
Keep the faucet open. As you treat the frozen pipe and the frozen area begins to melt, water will begin to flow through the frozen area. Running water through the pipe will help melt ice in the pipe.