How cold does it have to get before pipes freeze?

There is no single number, but the risk climbs when nights drop into the teens or a cold snap lasts several days. Water freezes at 32 degrees, and pipes in unheated spaces like crawlspaces, garages and exterior walls reach that point long before the rest of the house.

Should I drip the hot or the cold faucet?

Drip both if the faucet has separate lines. A slow, steady drip from each side keeps water moving through both the hot and cold pipes, which makes them harder to freeze.

What temperature should I leave my heat at when I travel in winter?

The American Red Cross recommends keeping the heat at 55 degrees or higher when you are away. For a long trip, also shut off the main water valve and drain the lines, or ask someone to check the house every day or two.

Is it safe to thaw a frozen pipe with a torch?

No. Never use a torch, open flame or charcoal to thaw a pipe. Use a hair dryer, a heating pad or warm towels, and keep the faucet open while you work.

What should I do if a frozen pipe bursts?

Shut off your main water valve right away, stay clear of water near outlets or the electrical panel, take photos, and call us. We pull out the water, dry the house, document the damage for your insurer and rebuild.

How to Prevent Frozen Pipes in Northern Virginia

To keep pipes from freezing, keep the heat on, let faucets on outside walls drip on the coldest nights, open the cabinets under sinks, and shut off and drain outdoor spigots before the first hard freeze. The pipes most at risk run through exterior walls, crawlspaces, garages and attics.

Why pipes freeze in Northern Virginia

Our winters are mild most of the time, and that is part of the problem. Many houses here were built with pipes in places that never see a long freeze: outside walls, crawlspaces, rooms over garages, and attics. When a cold snap pushes temperatures into the teens for a few nights, those pipes get cold enough to freeze while the rest of the house feels fine.

A frozen pipe does not always burst while it is frozen. Ice builds pressure between the blockage and the closest closed faucet until the pipe splits. The ice often holds the split shut. When it thaws, water comes out of the crack at full house pressure. That is why so many burst pipes show up the morning after the coldest night, or when someone comes home from a winter trip.

Before winter: a one-afternoon checklist

Disconnect garden hoses. A hose left on a spigot traps water in the fitting and the pipe behind it.
Shut off and drain outdoor spigots. Many homes have a small shutoff valve inside, in the basement or a utility area, for each outdoor spigot. Close it, then open the outdoor spigot to let the water drain out. Leave the outdoor spigot open for the winter.
Insulate exposed pipes. Foam pipe sleeves from a hardware store are cheap and quick to put on. Focus on pipes in crawlspaces, unfinished basements, garages and attics.
Seal cold air leaks. Look where pipes and cables come through outside walls and the rim joist in the basement. Caulk or foam small gaps so cold air does not blow straight onto a pipe.
Find your main water shutoff and test it. It is usually where the water line enters the house, often on the front wall of the basement or crawlspace, near the water heater, or in a utility closet. Turn it off and back on once so you know it works before you need it.
Close crawlspace vents if your house has them. Open vents let freezing air sit around the pipes all night.

On the coldest nights

Keep the thermostat steady. A big drop overnight saves a little on heating and puts pipes in outside walls at risk.
Let faucets drip. Pick the faucets on outside walls and let both hot and cold drip slowly. Moving water is much harder to freeze.
Open sink cabinet doors. Warm room air can then reach pipes tucked against a cold wall, especially in kitchens and bathrooms on the north side of the house.
Keep the garage door closed. Many homes have water lines in the garage or in the ceiling above it.
Townhome and condo owners: if the unit next door or above you is empty for the winter, tell your association. A freeze in a cold unit can send water into yours.

If you are leaving town

Keep the heat at 55 degrees or higher, which is what the American Red Cross recommends. For a trip of more than a few days, shut off the main water valve and open a faucet on the lowest floor to drain the lines. Ask a neighbor to check the house if a cold snap is in the forecast.

This also matters for insurance. Many homeowners policies do not cover freeze damage unless you kept the house heated or shut off the water and drained the system. Read more: Does homeowners insurance cover burst pipes?

How to tell if a pipe is frozen

You open a faucet and get nothing, or only a trickle, on a very cold morning.
You can see frost on an exposed pipe.
A section of pipe looks bulged or has a crack.

If you see a crack or water anywhere, skip the thawing and shut off the main valve first. A cracked pipe will leak the moment it thaws.

How to thaw a frozen pipe safely

Open the faucet the pipe feeds, so melting water has somewhere to go and pressure can drop.
Warm the pipe with a hair dryer, an electric heating pad, or towels soaked in hot water. Start near the faucet and work back toward the frozen section.
Keep going until full water pressure comes back.
Check the pipe and the area around it for drips over the next few hours.

Never use a torch, open flame, kerosene or propane heater, or charcoal. If you use a space heater, keep it well clear of anything that can burn and never leave it running alone. If the frozen section is inside a wall or you cannot find it, call a plumber.

If a pipe bursts

Shut off the main water valve, keep away from water near outlets and the electrical panel, take photos, and call us. Water spreads through drywall, insulation and subfloor fast, so the sooner it comes out, the less has to be torn out. We extract the water, dry the house until moisture readings say dry, document it for your insurer, and rebuild with the same crew. See how we handle burst pipe water damage.