Learning how to prevent frozen pipes is one of the smartest winter chores you can do: a single burst pipe can flood a room, ruin floors and furniture, and leave you with a repair bill running into thousands of dollars. The good news is that most frozen pipes are preventable.

Key Facts

• Pipes are most at risk when temperatures drop below 20 degrees Fahrenheit (about minus 7 Celsius), especially overnight.
• Pipes in unheated spaces — basements, crawl spaces, attics, garages, and exterior walls — freeze first.
• A burst pipe can release hundreds of gallons of water per hour into your home.
• Insulating exposed pipes is the single most effective prevention step you can take.
• Letting a tap drip during a deep freeze keeps water moving and relieves pressure inside the pipe.
• Knowing where your main water shut-off valve is can save your home if a pipe does burst.

Why Pipes Freeze in the First Place

Water expands as it freezes, putting enormous pressure on the walls of a pipe. A pipe does not usually burst where the ice forms: instead, the ice creates a blockage, pressure builds up between the blockage and a closed tap, and the pipe splits at its weakest point — which is why a frozen pipe can seem harmless and then suddenly flood a room as the ice thaws.

The pipes most likely to freeze are the ones you rarely think about: pipes along exterior walls, through unheated garages, or across cold basements and crawl spaces. Garden hoses left connected to outdoor taps are another common culprit, because they trap water in the tap and the first stretch of pipe.

Insulate Your Exposed Pipes

Insulation is the first and most important step in learning how to prevent frozen pipes. Foam pipe sleeves are cheap, easy to fit, and available at any hardware store. Focus on every pipe you can see or reach in unheated areas: the basement, the crawl space, the attic, the garage, and under sinks on exterior walls.

For extra protection in the coldest spots, wrap pipes with heat tape — an electrical cable that gently warms the pipe — before adding the foam sleeve. It is especially useful in very cold crawl spaces or regions with long, deep freezes. Follow the manufacturer’s instructions carefully, never overlap heat tape, and ask a plumber to fit it if you are unsure.

Seal Drafts and Cold Spots

Cold air leaking into your home is what freezes pipes, so sealing drafts is prevention at the source. Walk around on a cold, windy day and feel for drafts around windows, doors, and where pipes and cables pass through exterior walls. Seal gaps with caulk or expanding foam, fit draft excluders under doors, and make sure your attic hatch closes tightly.

Pay special attention to the wall behind your kitchen sink if it faces outside — one of the most common places for a frozen pipe, because cabinet doors trap cold air around the pipes while the room itself feels warm. Opening the cabinet doors on very cold nights lets warm room air circulate around the pipes. The same applies to bathroom vanities on exterior walls.

For more ideas on keeping the whole house warmer through winter, see our guide on how to keep your house warm without heating.

Let Taps Drip During a Deep Freeze

When a severe cold snap is forecast, letting a tap drip is a proven way to prevent a freeze: moving water is much harder to freeze than still water, and a slow drip also relieves pressure if ice does start to form. Choose the tap furthest from where the water enters your home, and let both hot and cold taps drip slightly.

You do not need to leave taps dripping all winter — save this step for nights when the forecast drops well below freezing. The small amount of water used costs far less than repairing a burst pipe.

If you are going away for a few days in winter, do not turn the heating off completely — keep the thermostat set to at least 55 degrees Fahrenheit (about 13 Celsius). A home that goes cold while empty is one of the most common settings for a burst pipe discovered too late.

Disconnect Hoses and Shut Off Outdoor Taps

Outdoor taps deserve their own winter routine. Disconnect all garden hoses before the first hard frost, drain them, and store them in a garage or shed. A connected hose traps water in the tap and the pipe behind it, and that trapped water freezes, expands, and cracks the pipe — often inside the wall where you cannot see the damage until spring.

If your home has a separate shut-off valve for outdoor taps, close it and open the tap to drain the remaining water, then fit an inexpensive insulated cover over each outdoor tap.

Keep the Heat On and Even

A steady indoor temperature is your best defence against frozen pipes, so avoid letting the temperature drop sharply at night or while you are out. Set a modest overnight temperature rather than switching the heating off entirely — the small amount of energy saved is not worth the risk.

Make sure warm air can reach every room: keep interior doors open so heat circulates, especially to rooms with plumbing, and do not close off a rarely used room and let it go cold — the pipes in its walls are still at risk.

Know What to Do If a Pipe Freezes

Even with good prevention, a pipe can freeze in an extreme cold snap. If you turn on a tap and only a trickle comes out, or nothing at all, a pipe may be frozen. Keep the tap open, because water will flow again once the ice melts and the open tap gives the pressure somewhere to go. You can learn the full safe thawing process in our guide on how to thaw frozen pipes.

Never use an open flame, a blowtorch, or a propane heater to thaw a pipe — use a hair dryer, a heating pad, or towels soaked in hot water, working from the tap end back towards the frozen section. If you cannot find the frozen section, or a pipe has burst, turn off the main water supply immediately and call a plumber.

Finding your main shut-off valve before winter is a five-minute job that can save thousands of dollars. It is usually near the water meter, in the basement, or under the kitchen sink — show everyone in the household where it is and how to turn it. The federal government’s Ready.gov’s winter weather safety guidance also recommends having an emergency plan and supplies ready before a winter storm arrives.

A Simple Winter Checklist

Before the first frost, insulate exposed pipes, disconnect hoses, seal drafts, and find your shut-off valve. During cold snaps, open cabinet doors under exterior-wall sinks, let a tap drip, and keep the heating steady.

While you are checking pipes under the kitchen sink, it is a good moment to sort the space too — our small kitchen organization ideas can help you make the most of that cupboard. A little preparation now means a warm, dry, worry-free home all winter long.

Frequently Asked Questions

At what temperature do pipes freeze?
Pipes can start to freeze at 20 degrees Fahrenheit (about minus 7 Celsius) or below, especially if the cold lasts several hours. Pipes in unheated spots can freeze at slightly higher temperatures.

Should I let my taps drip all winter?
No. Let taps drip only during deep freezes, when temperatures fall well below freezing and stay there overnight. A slow trickle from the tap furthest from your water entry point is enough.

Does pipe insulation really prevent freezing?
Yes — foam pipe insulation is the most effective single step you can take. It slows heat loss and keeps the water inside above freezing for much longer, and in very cold spots you can combine it with heat tape.

Which pipes are most likely to freeze?
Pipes in unheated spaces freeze first: basements, crawl spaces, attics, garages, and pipes inside exterior walls. Outdoor taps and pipes behind kitchen sinks on exterior walls are also common trouble spots.

What should I do if a pipe bursts?
Turn off the main water supply immediately, open taps to drain the system, and call a plumber. Move valuables away from the water, and do not touch electrical outlets or switches near standing water.

Is it safe to thaw a frozen pipe myself?
Yes, if you use gentle heat such as a hair dryer, heating pad, or hot towels, and you work from the tap end back towards the frozen section. Never use an open flame or blowtorch, and call a plumber if you cannot locate the frozen section or the pipe has cracked.