Preventing Frozen Water Pipes

Pipes in unheated buildings or crawl spaces can be prone to freezing during cold temperatures. While sometimes this results in simply an inconvenient loss of water in certain parts of the home, it can become more serious if the water freezes. As water freezes, it expands inside the pipe, which could cause the pipe to burst and potentially result in extensive water damage.

To help avoid problems due to frozen water lines, here are some tips to follow when the temperature dips below freezing in cold climates:

Let a thin stream of cold water run from a faucet. The stream should be a continuous flow, about the thickness of a pencil. This water can be caught in a bucket or pail to be recycled for another purpose later, if desired.
Be sure pipes in unheated areas of the home or crawl space are insulated. Many hardware and home improvement stores carry foam insulation for this purpose.
Leave interior cupboard doors under sinks open, especially if the water pipes are adjacent to an exterior wall. This will allow heat from the room access to the pipes.
Plug drafty cracks and repair broken windows that could allow cold air to get inside where pipes are located.
Shut off and drain pipes leading to outside faucets.
If you leave your home for several weeks during the winter, have someone regularly check your home to be sure the heat is on and that no pipes have frozen or burst.
You can also check with your local water department to see if they offer a seasonal shutoff service. If so, your water can be shut off at the street, then a plumber can come and drain your pipes/hot water tank.
Know the location of the main water shutoff valve in your home. Check it periodically to ensure it works properly.

If you lose water service in one or more areas of the home, check to see if you can isolate the frozen location. Common areas that freeze first are pipes located adjacent to exterior walls or where the water service line enters the home through the foundation. Apply heat to the suspected section of the exposed pipe carefully, using one of the following methods:

An electric hair dryer, carpet sweeper exhaust, or light bulb.
Heat tape can be used, with care taken to install according to the manufacturer's specifications.

Never use antifreeze to thaw a pipe, since it can contaminate the water supply and make it unsafe to drink.

Also, never attempt to thaw pipes with a torch or other open flame, as such methods risk starting a fire. If you are unable to thaw the pipe yourself, contact your local water department, landlord, or a plumber for professional assistance.

For additional information, please visit Disaster Readiness Tips or contact NSF (info@nsf.org).