Frozen pipes: how to prevent them, thaw them, and what to do if one bursts

When temperatures drop below freezing, pipes in cold spots can freeze and break. Here is how the American Red Cross recommends protecting pipes, thawing them safely, and what to do if one breaks.

Why frozen pipes burst

Water expands as it freezes. The Red Cross explains that this expansion puts tremendous pressure on whatever holds the water, metal or plastic, and no matter how strong the pipe is, expanding water can break it.

Which pipes freeze most often

According to the Red Cross, the pipes that freeze most frequently are:

• Pipes exposed to severe cold, like outdoor hose bibs, swimming pool supply lines and sprinkler lines
• Water supply pipes in unheated interior areas, like basements, crawl spaces, attics, garages and kitchen cabinets
• Pipes that run along exterior walls with little or no insulation

Before cold weather arrives

The Red Cross recommends these steps before the first freeze:

• Drain swimming pool and sprinkler supply lines following the manufacturer's or installer's directions. Don't put antifreeze in these lines unless directed.
• Remove, drain and store outdoor hoses. Close the inside valves that supply outdoor hose bibs, open the outside bibs to drain, and leave them open so remaining water can expand without breaking the pipe.
• Add insulation to attics, basements and crawl spaces.
• Check the garage and under kitchen and bathroom cabinets for supply lines in unheated areas, and insulate both hot and cold pipes there.
• Consider pipe sleeves or UL-listed heat tape or heat cable on exposed pipes.
• Consider relocating exposed pipes to give them more protection from freezing.

Antifreeze doesn't belong in these lines unless the manufacturer says so. The Red Cross points out that it's environmentally harmful and dangerous to people, pets, wildlife and landscaping.

Even simple insulation helps. In areas that don't usually see long stretches below freezing, the Red Cross notes that even a quarter inch of newspaper wrapped around an exposed pipe can give it significant protection.

During a cold snap

When temperatures drop, the Red Cross advises:

• Keep garage doors closed if there are water lines in the garage.
• Open kitchen and bathroom cabinet doors so warmer air reaches the plumbing, and move cleaners and chemicals out of children's reach.
• Let cold water drip from faucets served by exposed pipes. Water moving through the pipe, even at a trickle, helps prevent freezing.
• Keep the thermostat at the same temperature day and night. A higher heating bill costs far less than repairing a burst pipe.
• If you'll be away, leave the heat on and set no lower than 55 degrees Fahrenheit.

How to tell if a pipe is frozen

The first sign is usually at the faucet: you turn it on and only a trickle comes out, or nothing at all. Start with the pipes most likely to freeze, the ones along exterior walls, in unheated spaces like the garage, attic or crawl space, and where the water line enters the house through the foundation.

How to thaw a frozen pipe safely

If you turn on a faucet and only a trickle comes out, suspect a frozen pipe. The Red Cross says likely spots are against exterior walls or where the water service enters through the foundation. To thaw it:

1. Keep the faucet open, so melting ice can flow out and running water can help melt the rest.
2. Warm the frozen section with an electric heating pad, a hair dryer, a portable space heater kept away from anything flammable, or towels soaked in hot water.
3. Never use a blowtorch, kerosene or propane heater, charcoal stove or any open flame.
4. Keep applying heat until full water pressure returns.
5. Check every other faucet in the house. If one pipe froze, others may have too.

If you can't find the frozen section, can't reach it, or can't thaw it, the Red Cross recommends calling a licensed plumber.

If a pipe bursts

Shut off the water at the main valve first, then call a plumber to repair the pipe. Knowing where your main shut-off valve is before winter makes this step much faster.

Next, think about drying. Water from a burst pipe can soak into drywall, insulation and subfloors where you can't see it, so get it dried out as quickly as you can.

Take photos of the damage before cleanup starts, since you may need them for your insurance claim, and keep receipts for any emergency repairs.

How we help with burst pipes

We handle busted pipes and the flooding that follows: advanced water extraction, structural drying for all types of water damage, and the hidden water that can make damage worse. We keep complete documentation of the job and coordinate with your insurance company. Our emergency line is open 24 hours a day, 7 days a week, across Charlotte and 16 counties in North and South Carolina.