How to Prevent Frozen Pipes: Heat Tape, Insulation and Covers

To prevent frozen pipes, insulate pipes in unheated spaces, drain and disconnect outdoor hoses, keep garage doors closed, open sink cabinets, let a faucet on exposed pipes drip in hard cold, and keep the thermostat at the same setting day and night, as the American Red Cross advises. Away from home, keep the heat at 55°F or higher.

Why do pipes freeze and burst?

Water expands as it freezes. The American Red Cross explains that this expansion puts enormous pressure on whatever holds the water, and no pipe, metal or plastic, is strong enough to stop it breaking.

Which pipes are most likely to freeze?

The Red Cross names three groups:

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

Walk the house with that list before the first hard freeze. Check under kitchen and bathroom sinks, in the garage and anywhere a pipe runs along an outside wall.

What should you do before cold weather arrives?

These steps come from the Red Cross, in the order that makes sense for a fall weekend.

1. Drain the outdoor lines. Drain pool and sprinkler supply lines following the manufacturer’s or installer’s directions. Do not add antifreeze unless directed; the Red Cross notes it is harmful to people, pets, wildlife and landscaping.
2. Deal with the hoses. Remove, drain and store outdoor hoses. Close the inside valves that feed outdoor hose bibs, then open the outside bibs so they drain. Leave the outside valve open so any leftover water can expand without breaking the pipe.
3. Insulate the cold spaces. Add insulation to attics, basements and crawl spaces to keep them warmer.
4. Insulate exposed pipes. The Red Cross says both hot and cold pipes in unheated areas should be insulated, and suggests pipe sleeves or UL-listed heat tape, heat cable or similar products.
5. Consider moving pipes. Relocating exposed pipes gives them more protection.

Ready.gov adds the whole-house version: prepare your home to keep out the cold with insulation, caulking and weather stripping.

Insulated covers for outdoor faucets are sold for hose bibs too. The Red Cross steps come first: shut the inside valve and drain the bib before you cover it.

How do you install heat tape safely?

Heat tape and heat cable are electric heaters wrapped along a pipe, and CPSC treats them as a fire risk when misused. In a 1996 release, it said faulty electric heat tapes caused about 1,500 fires, 10 deaths and 100 injuries a year. Install any tape exactly as its maker’s instructions say, and follow CPSC’s guidelines:

• Plug the 3-prong plug into a 3-prong outlet so the tape is grounded.
• Use an outlet protected by a ground-fault circuit-interrupter (GFCI).
• Apply the tape directly on the pipe, never on top of insulation covering the pipe.
• Do not wrap the tape over itself unless the maker’s instructions specifically permit it.
• Do not cover the tape with insulation unless the maker advises it. If you do, use non-flammable insulation such as fiberglass.
• Keep the end cap sealed and off the ground so water cannot get in.
• Do not use heat tape made for water pipes on gutters, driveways or fuel lines.
• Inspect it every year and replace it if it shows signs of wear. CPSC also says to replace uncertified tapes more than 3 years old with certified ones.

The Red Cross specifically recommends UL-listed heat tape or heat cable, so check the package for the listing mark.

How do you keep pipes from freezing during a storm?

When the cold arrives, the Red Cross advice shifts to keeping warm air near the pipes and water moving through them.

Keep the garage closed if water lines run through it.

Open the cabinet doors under kitchen and bathroom sinks so warmer room air reaches the plumbing. Move cleaners and chemicals out of children’s reach first.

Let a faucet drip. In very cold weather, let cold water drip from a faucet served by exposed pipes. The Red Cross says even a trickle helps prevent freezing.

Hold the thermostat steady. Keep the same setting day and night. The Red Cross acknowledges this may raise your heating bill, but says it can prevent a much more costly repair if pipes burst.

Leaving town? Leave the heat on, set to no lower than 55°F.

If the power fails and the house starts to cool, backup heat matters. Our guides to space heaters in a power outage and portable generators for winter outages cover the safety rules for both.

How do you thaw a frozen pipe?

The Red Cross says to suspect a frozen pipe if only a trickle comes out when you turn on a faucet. Look first at pipes against exterior walls and where the water service enters through the foundation.

1. Keep the faucet open. As the ice melts, running water helps melt the rest.
2. Apply gentle heat. Use an electric heating pad wrapped around the pipe, a hair dryer, a portable space heater kept away from flammable materials, or towels soaked in hot water.
3. Keep going until full water pressure returns.
4. Check every other faucet. If one pipe froze, others may have too.

Call a licensed plumber if you cannot find the frozen section, cannot reach it or cannot thaw it.

If you use a space heater to thaw a pipe, CPSC’s heater rules still apply: plug it straight into a wall outlet, never an extension cord, and keep anything that can burn at least 3 feet away.

Our carbon monoxide safety guide covers alarm placement and warning signs. For snow piling up on the roof, see roof rakes and ice dams on clearing it from the ground. The full storm checklist is in our winter storm preparedness guide.