From Spotlight: Light up Your Home This Winter

How to Unfreeze Pipes & Prevent Damage

These tips will help you thaw your frozen water pipes and avoid extensive damage.

frozen copper pipe bursting
Image: BanksPhotos/Getty

The best way to deal with freezing pipes is to prevent them

But if a pipe freezes and bursts, you’ll have to act fast to minimize damage and repair costs.

Related: How to Keep Your Pipes From Exploding This Winter

Why Freezing Pipes Burst

Not all freezing pipes burst, explains Paul Abrams, spokesman for Roto-Rooter. But when one does burst, it's because water expands when it freezes. That adds pressure on unyielding plumbing pipes, and pressure can cause a tiny leak at a joint or crack on the pipe. The leak, in turn, unleashes the full flow of water inside your home.

Water damage from bursting pipes is one of the most common homeowners insurance claims. The average claim costs about $10,900.

How to Identify Freezing Pipes

A water line coated in frost (or bulging like a well-fed python) is a good sign that a pipe is frozen. But not all plumbing pipes are visible. “If your faucets won't flow and your toilets won't refill following a flush, that's a good sign your pipes are frozen,” says Abrams.

How to Thaw a Frozen Pipe

First, shut off the water supply to that section of plumbing (or the entire house if that's the only option). The real trouble begins after the thaw. The frozen water may prevent water from spilling out of the cracks in your pipes. But when that plug thaws, water gushes out. Be ready with a mop, bucket, and towels in case there’s a plumbing leak.

Use a space heater, heat lamp, or hair dryer to thaw the frozen length of pipe. Wrapping freezing pipes with thermostatically controlled heat tape (from $25 to $61, depending on length) can also quickly thaw a trouble spot.

Don’t thaw pipes using a propane torch, which presents a fire risk.

What to Do If a Pipe Bursts

If you walk in to discover Old Faithful in your basement, first shut off the main water supply to minimize flooding. Next, call your plumber.

Immediately remove as much water as possible using mops, sponges, towels, and a wet/dry vacuum. To minimize mold, mildew, and other moisture-related problems, run a dehumidifier in the space until it's very dry.

For big messes, call your insurance agent. The good news: Most homeowners insurance covers burst pipes and the resulting water damage.

A Few Words About That Main Water Shutoff Valve

“Everybody should know where it is,” says Abrams. “The sooner you can shut off the water, the less it will cost you.”

Homeowners should not only know where the valve is located, but they also have a plumber inspect it the next time they are on site. If your home has an older gate-style valve, consider investing $240 to $500 to replace it with a more reliable ball valve.

Gate valves are prone to sticking when you need them the most. So, it's a good idea to exercise them once a year by rotating them back and forth.

Related: What Not to Do as a New Homeowner

Doug Trattner
Douglas Trattner

Douglas Trattner has covered home improvement for HGTV.com, DIYNetworks, and the Cleveland Plain Dealer. He lives in a 1925 Colonial.