How to Prevent Frozen Pipes in Winter

A burst pipe from freezing can cause thousands of dollars in water damage in minutes. The good news: preventing frozen pipes is cheap, simple, and takes a single afternoon of work before winter arrives.

Why Pipes Burst

When water freezes, it expands by about 9%. Inside a sealed pipe, this expansion creates enormous pressure — enough to split copper, PVC, and even steel. The burst often doesn’t happen where the ice forms, but downstream where pressure builds up.

The worst part: you often don’t know a pipe has burst until the ice thaws and water starts flowing — sometimes while you’re away from home.

Prevention Steps

1. Insulate Exposed Pipes

Foam pipe insulation sleeves cost $1-3 per foot and are the single most effective prevention measure.

• Where to insulate: Pipes in the basement, crawl space, attic, garage, and along exterior walls.
• How to install: Slide the foam tube over the pipe and press the self-adhesive edge closed. Cut to length with a utility knife.
• Extra protection: In very cold climates, wrap insulated pipes with heat tape for added warmth.

2. Seal Air Leaks

Cold air reaching pipes causes freezing. Seal entry points:

• Caulk or spray foam around pipe penetrations in exterior walls.
• Seal cracks in the foundation, basement, and crawl space walls.
• Weatherstrip doors and windows near exposed pipes.

3. Prepare Outdoor Plumbing

• Disconnect all garden hoses from exterior faucets.
• Shut off interior supply valves for outdoor spigots (if your home has them).
• Drain remaining water from the spigot by opening it after shutting off the supply.
• Install insulated faucet covers on exposed outdoor spigots.

4. Keep Water Moving

Moving water freezes much more slowly than standing water.

• During extreme cold (below 20°F / -7°C), let faucets drip slightly — just enough to see movement.
• Prioritize faucets served by pipes in exterior walls or unheated areas.
• Open both hot and cold lines — even a trickle helps.

5. Use Indoor Heat

• Open cabinet doors under kitchen and bathroom sinks, especially those on exterior walls.
• Keep the garage door closed if water pipes run through it.
• Maintain consistent heat — set the thermostat no lower than 55°F (13°C), even at night or when away.

6. Know Your Main Shutoff

Find your main water shutoff valve before you need it. If a pipe does burst:

1. Shut off the main valve immediately.
2. Open all faucets to drain the remaining water.
3. Call a plumber.

How to Thaw a Frozen Pipe

If you suspect a pipe is frozen but hasn’t burst:

1. Open the faucet served by the frozen pipe.
2. Apply heat starting from the faucet end and working toward the frozen section.
3. Use a hair dryer (move it back and forth — don’t hold it in one spot).
4. Wrap pipes in hot towels or use a heating pad.
5. Never use an open flame (blowtorch, propane heater) — this is a fire hazard and can damage the pipe.

Comparison

The Bottom Line

Foam pipe insulation is the best investment — it costs a few dollars per foot and prevents most freezing. Combine it with sealing air leaks, disconnecting outdoor hoses, and letting faucets drip during extreme cold, and your pipes will be well-protected all winter.

Related Guides

• How to fix a leaky faucet — repairing leaks before winter helps prevent freeze-related damage.
• How to stop condensation on windows — both address moisture and temperature management in the home.