Why Pipes Burst in Cold Weather
Pipes burst when water inside them freezes and expands, building pressure that the pipe walls cannot contain. The burst typically does not occur at the ice plug itself but downstream where pressure builds. Pipes most at risk: exterior walls, unheated crawl spaces, attics, garages, and areas near exterior doors. Copper and PVC are both vulnerable — PEX tubing is more flexible and somewhat more resistant.
Prevention: Insulation
Insulate pipes in unheated spaces with foam pipe insulation — available at hardware stores in pre-slit tubes that snap around pipes. Pay special attention to pipes in exterior walls, crawl spaces, attics, and garages. Insulate the area around the pipes rather than just the pipe itself for better protection. Install insulated blankets on water heaters in cold garages.
Prevention: Heat Tape and Cable
Self-regulating heat cable is an effective solution for pipes in chronically cold locations. The cable wraps around the pipe and plugs into a standard outlet — self-regulating versions automatically adjust heat output based on temperature. Follow manufacturer instructions carefully — improperly installed heat tape can be a fire hazard. Inspect heat cable annually before winter.
What to Do When Temperatures Drop Dangerously Low
- Open cabinet doors under sinks on exterior walls to allow heat to reach pipes
- Let faucets drip slightly — moving water freezes at lower temperatures
- Keep thermostat at minimum 55°F even when away
- Know the location of your main water shutoff valve — find it before you need it
- If leaving for an extended period in winter, drain the water system or hire someone to check the home
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