When water freezes, it expands. Trapped in a closed pipe, that expansion creates pressure strong enough to split copper, crack PVC, and blow out pipe joints. The result: a burst pipe that can release hundreds of gallons of water into your walls, floors, and ceilings. The Insurance Institute reports that frozen pipe bursts are one of the most common and costly homeowner insurance claims, averaging $15,000 per incident.
The good news: with a few hours of autumn preparation, frozen pipes are almost entirely preventable.
Which Pipes Are at Risk?
Pipes most vulnerable to freezing are those with minimal insulation and exposure to cold air:
- Pipes in unheated spaces: garages, crawlspaces, attics, unfinished basements
- Pipes running through exterior walls
- Outdoor hose bibs and irrigation supply lines
- Pipes in kitchen or bathroom cabinets on exterior walls
Step 1: Disconnect and Drain Outdoor Hoses
Before the first freeze, disconnect all garden hoses from outdoor faucets and drain them. Water left in a connected hose can freeze back into the faucet and pipe indoors. Store hoses in a garage or shed for winter.
Step 2: Shut Off and Drain Outdoor Faucets
Most modern homes have frost-free (anti-siphon) hose bibs that drain automatically when the water is off — but they only work if the hose is disconnected. For older standard hose bibs, locate the interior shut-off valve (usually in the basement or utility room) and turn it off. Then open the outdoor faucet to drain remaining water from the pipe.
Step 3: Drain Irrigation Systems
If you have in-ground irrigation, blow out the system with compressed air (or hire a landscaper) before freezing temperatures arrive. Even a small amount of water trapped in irrigation lines can crack the pipes or heads. Turn off the irrigation system's water supply and shut off the controller.
Step 4: Insulate Vulnerable Pipes
Foam pipe insulation (pipe wrap) is inexpensive — $0.50–$1.50 per foot — and easy to install. Cut to length, slit lengthwise, and wrap around pipes in unheated spaces. Pay special attention to pipes in crawlspaces, attics, and garages. For extreme cold, use electric heat tape under the insulation on the most exposed runs.
Step 5: Seal Air Leaks Near Pipes
Cold air drafts around pipes — through gaps in the sill plate, around penetrations where pipes pass through exterior walls, or through foundation cracks — accelerate freezing. Use spray foam insulation or caulk to seal any openings where cold air can reach interior pipes.
During Cold Snaps
- Keep your home heated to at least 55°F even when away or traveling
- Open cabinet doors under sinks on exterior walls to allow warm air to circulate
- Let cold water drip from faucets served by exposed pipes — moving water is significantly harder to freeze
- If you're away for an extended period, have someone check the house regularly or install a smart thermostat with freeze protection alerts
If a Pipe Does Freeze
If a faucet stops producing water in freezing weather, you likely have a frozen pipe. Do NOT use an open flame to thaw it — this has started house fires. Use a hair dryer, heating pad, or portable space heater near the pipe. Start from the faucet end and work back toward the supply. Turn on the faucet so water can flow as soon as the ice melts — this releases pressure and confirms water is moving. If you can't locate the frozen section or can't thaw it safely, call a plumber. And be prepared: a pipe that froze has likely been stressed and may have developed a crack that won't be apparent until it thaws.