Water expands when it freezes, and pipes in cold spots can crack or split under that pressure. The damage often shows up later, when the ice thaws and water starts flowing through the break. Pipes in unheated spaces, along exterior walls and outdoors at hose bibs are the usual trouble spots.
This checklist covers the supplies worth buying before winter, where each one goes, how to use heat cable safely, what to do on the coldest nights, and how to thaw a frozen pipe without starting a fire.
Quick answer
- Outdoors first: disconnect hoses, shut off and drain exterior faucets if you have an indoor valve, and add insulated faucet covers.
- Insulate exposed pipes in crawl spaces, attics, garages and exterior-wall cabinets with foam pipe sleeves.
- Heat cable is for pipes that insulation alone can’t protect. Use a listed product, follow its instructions exactly and plug it into a GFCI-protected outlet.
- On the coldest nights: keep the heat on, open cabinet doors on exterior walls, and let a faucet fed by vulnerable pipes drip.
- If a pipe freezes, thaw it with gentle heat like a hair dryer. Never use an open flame.
Find the pipes most at risk
Walk the house and note these
- Outdoor hose bibs (spigots) and any hoses still attached to them
- Pipes in crawl spaces, unheated basements and attics
- Pipes in an attached garage, especially near the garage door
- Kitchen and bathroom supply lines in cabinets on exterior walls
- Pipes running through exterior walls with little insulation
- Lawn sprinkler supply lines
Also find your main water shutoff valve now, while nothing is leaking. Make sure everyone in the household knows where it is and that it turns. If a pipe bursts, shutting off the water quickly limits the damage.
The supplies, and where each one goes
| Supply | Where it goes | Notes |
|---|---|---|
| Foam pipe insulation sleeves | Exposed pipes in crawl spaces, basements, attics, garages, cabinets | Match the sleeve to the pipe diameter; tape the seams and joints |
| Insulated outdoor faucet covers | Over exterior hose bibs | Fit snugly against the wall; use after disconnecting the hose |
| Hose bib shutoff access | Indoor valve feeding each outdoor faucet | Close the valve, then open the outdoor faucet to drain the line |
| Heat cable (heat tape) | Pipes insulation alone can’t protect | Use a listed product, follow its instructions, plug into a GFCI outlet |
| Temperature and leak sensors | Under sinks, near the water heater, in crawl spaces | Alert your phone or sound an alarm when it’s cold or wet |
| Foam or caulk for gaps | Where pipes pass through exterior walls | Seals cold drafts that chill pipes |
Outdoor faucets and hoses
- Disconnect and drain hoses. A hose left attached traps water in the faucet, which can freeze back into the pipe. Drain hoses and store them.
- Close the indoor shutoff. Many outdoor faucets have a separate shutoff valve inside the house. Close it.
- Drain the outdoor faucet. Open the outdoor faucet to let water drain out of the line, then leave it as your plumber or the valve design recommends.
- Cover it. Fit an insulated faucet cover snugly over the spigot.
Some homes have frost-free faucets designed to drain themselves. They only work as intended if the hose is disconnected, so the hose step still matters.
If you have a lawn sprinkler system, follow the installer’s or manufacturer’s winterization steps, or have it blown out by a professional before the first hard freeze.
Heat cable: when to use it and how to stay safe
Heat cable (often called heat tape) is an electric cable that warms a pipe. It is useful for pipes in places that get cold enough that insulation alone is not enough, like a crawl space or a mobile home supply line.
Two common types
Self-regulating
Adjusts its heat output along its length based on temperature. Generally more forgiving to install. Still follow the manufacturer’s instructions for crossing or overlapping.
Constant-wattage
Puts out the same heat all the time, often with a thermostat. Typically must never be overlapped or crossed over itself, because that can overheat.
What to do on the coldest nights
Hard-freeze night checklist
- Keep the heat on, day and night. If you’re going away, the American Red Cross recommends leaving the heat set no lower than 55°F.
- Open kitchen and bathroom cabinet doors on exterior walls so warm room air reaches the pipes. Move cleaning products out of reach of kids and pets.
- Let cold water drip from a faucet fed by exposed pipes. Moving water is less likely to freeze.
- Keep the garage door closed if water lines run through the garage.
- Check that crawl space vents and doors are closed if your home’s design calls for it.
- Watch your phone for alerts if you have temperature or leak sensors.
A power outage during a deep freeze raises the stakes. Our winter outage supplies list and generator vs power station guide cover how to keep critical heat and power going safely.
If a pipe freezes: how to thaw it safely
The first sign is often a faucet that gives only a trickle or nothing at all when it’s very cold outside.
- Leave the faucet open. As the ice melts, flowing water helps melt the rest and relieves pressure.
- Find the frozen section. Look along exposed pipe for frost or the coldest spot, often in an exterior wall or unheated space.
- Apply gentle heat. Use a hair dryer, an electric heating pad wrapped around the pipe, or towels soaked in hot water. Work from the faucet end back toward the frozen section.
- Keep going until full pressure returns. Then check all other faucets for frozen lines.
- Call a licensed plumber if you can’t find or reach the frozen section, or if thawing doesn’t restore flow.
If a pipe bursts
Shut off the main water valve immediately, turn off electricity to the affected area if water is near outlets or appliances and it’s safe to reach the panel, and call a plumber. Photograph damage for your insurer.
A five-minute fall routine
Most frozen pipes trace back to a skipped step in fall. Put this on the calendar for the first cold snap each year:
- Disconnect hoses, close and drain outdoor faucet lines, add covers.
- Check pipe insulation in the crawl space, garage and attic for gaps or damage.
- Inspect heat cable and test the GFCI outlet it plugs into.
- Test leak and temperature sensors and replace their batteries.
- Confirm the main shutoff valve turns and is easy to reach.
It pairs well with the rest of your winter prep: the snow blower tune-up, stocking ice melt and checking the roof edge. See ice dams explained for the roofline side of the same cold-weather problem.
FAQ
What temperature do pipes freeze at?
There is no single outdoor temperature; it depends on where the pipe runs, how well it is insulated, wind and how long the cold lasts. Pipes in unheated spaces and exterior walls are at risk during any hard freeze, so prepare them before winter.
Should I let my faucets drip to prevent freezing?
Letting cold water drip from a faucet fed by exposed pipes is a common recommendation for very cold nights. Moving water is less likely to freeze, and an open faucet relieves pressure if ice does form.
Is heat tape safe?
It can be when you use a listed product suited to your pipe, install it exactly as instructed, plug it into a GFCI-protected outlet and inspect it each year. Damaged or improperly installed cable is a fire risk.
How do I know if a pipe is frozen?
A faucet that produces only a trickle or nothing in very cold weather is the classic sign. You may also see frost on an exposed section of pipe.
Can I use a space heater to thaw a frozen pipe?
An electric space heater can warm the area if used safely: keep combustibles at least three feet away, never leave it unattended and plug it directly into a wall outlet. Never use open flames or fuel-burning heaters indoors.
Bottom line
Our take: the cheapest protection does the most work. Disconnect hoses, cover outdoor faucets, sleeve exposed pipes and keep the heat on. Add a leak sensor or two for peace of mind, and use heat cable only where you need it, installed by the book.
And know where your main shutoff is before you need it.