Frozen Pipe
A frozen pipe is a supply pipe in which the water inside has frozen solid, blocking water flow to fixtures and creating pressure that can crack or burst the pipe when it thaws. The Insurance Institute for Business and Home Safety identifies frozen and burst pipes as one of the most common — and most costly — sources of winter property damage, with the average claim exceeding $15,000.
Where pipes freeze
Pipes freeze in locations that reach 32°F or below. High-risk zones:
- Exterior walls with inadequate insulation
- Unheated crawl spaces, garages, and attics
- Pipes near the foundation rim joist (the band of wood at the slab edge)
- Supply lines running through cabinet spaces under sinks on exterior walls
- Vacant homes with heating turned off or failed
- Outdoor hose bibs and irrigation lines not drained for winter
How to thaw a frozen pipe safely
If you turn on a faucet and no water comes out in freezing weather, you likely have a frozen pipe. First, open the affected faucet — this releases pressure when the ice melts. Then apply gentle heat from the faucet toward the freeze location:
- Hair dryer on low — the safest method for accessible pipes
- Heating pad wrapped around the pipe
- Warm towels soaked in hot water
- Space heater aimed at the pipe area (keep away from flammables)
Never use: open flames (propane torch), heat guns at close range, or any device that can scorch the pipe or surrounding materials. Never thaw a pipe you can't see — if the pipe is inside a wall, call a plumber.
If the pipe has burst
Close the main shutoff valve immediately to stop water flow. A burst pipe typically doesn't reveal itself until the ice melts — so a frozen pipe that seemed fine can flood within minutes of thawing. After shutting off the water, call a plumber to replace the damaged section.
Prevention
Pipe insulation, heat tape, and maintaining interior temperatures above 55°F are the primary defenses. Drip outdoor-facing faucets during extreme cold to maintain slight flow (moving water resists freezing). Drain irrigation systems and hose bibs before the first hard freeze.