Preventing Frozen Pipes

— Written By Trudy Pickett and last updated by

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. Also, pipes that run against exterior walls that have little or no insulation are also subject to freezing. Prevent freezing of water supply lines and pipes by following these recommendations:

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 cause the pipe to break.

Check around the home for other areas where water supply lines are located and are 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. A hot water supply line can freeze just as a cold water supply line can freeze if the water is not running through the pipe and the water temperature in the pipe is cold.

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. Many products are available at your local building supplies retailer. Pipes should be carefully wrapped, with ends butted tightly and joints wrapped with tape. Follow the manufacturer’s recommendations for installing and using these products. Newspapers can provide some degree of insulation and protection to exposed pipes – even 1⁄4” of newspaper can provide significant protection in areas that usually do not have frequent or prolonged temperatures below freezing.

Take preventive action during cold weather by keeping 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 

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 because the temperature of the water running through it is above 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 turn on a faucet and only a trickle comes out, suspect a frozen pipe. If pipes freeze, shut off water valves. Stopping the flow of water can minimize the damage in your home. Call a plumber to thaw your pipes. Thawing yourself can lead to greater damage and can be a hazard. If your pipes burst, call a plumber and your insurance agent. Find more information about this topic at

Resources: American Red Cross, NC State University.