Water pipes in your home can burst when freezing temperatures create ice. As ice continues to form, water trapped between the blockage and your faucet can be subjected to tremendous pressure, causing pipes to spring leaks. Many people think that the ice itself causes pipes to burst, but the Building Research Council of the University of Illinois has shown otherwise. A temporary solution: allow the faucet to drip slowly. While this may not prevent an ice blockage, it can prevent the pressure from building up and possibly bursting your pipes. If the faucet stops dripping, don't close it--the pressure still may need to be released.
Pipes that snake through attics, crawl spaces, or exterior walls--especially poorly insulated pipes--are most likely to freeze. You probably have a frozen pipe if the faucet or appliance relying on it isn't getting flowing water. Where you can, cover water pipes with insulation. If freezes are common where you live, consider warming the problem pipes with electric heat tape.
As for outside spigots, turn off the water to these lines and drain them.
Ironically, burst pipes are a real problem in the South; building practices there may not adequately protect pipes from occasional sub-freezing temperatures, the Building Research Council says. The threshold: 20 degrees Fahrenheit or below.
