Every Canadian winter, cold snaps catch homeowners and tenants off guard. A pipe that freezes can crack or burst, and the resulting water damage is often far more expensive than the repair itself. The good news is that learning how to prevent frozen pipes takes little time and very little money. This guide covers the simple steps to take before the deep cold arrives, what to do during extreme weather, and how to react if a pipe does freeze.
Why Pipes Freeze and Burst
Water expands when it freezes. When ice forms inside a pipe, pressure builds between the ice blockage and the closed tap. That pressure, not the ice itself, is often what causes a pipe to split. The most vulnerable pipes are those in places that get cold:
- Unheated basements, crawl spaces, garages and attics
- Pipes running along exterior walls, especially behind kitchen and bathroom cabinets
- Outdoor faucets, hose bibs and sprinkler lines
- Pipes near drafty windows, dryer vents or gaps in the foundation
Before Winter: Prevention Checklist
Most of the work happens in the fall, before temperatures drop well below freezing.
Shut off and drain outdoor taps
Close the indoor shut-off valve that feeds each outdoor faucet, then open the outdoor tap to let remaining water drain. Disconnect and store garden hoses; a connected hose can trap water and cause the faucet to freeze. If you have a frost-free faucet, still disconnect the hose.
Insulate exposed pipes
Foam pipe sleeves from a hardware store are inexpensive and easy to install. Focus on pipes in unheated areas and along exterior walls. For pipes that are especially exposed, a certified heat cable installed according to the manufacturer’s instructions can help.
Seal drafts
Cold air leaking through gaps around pipes, vents and the foundation can freeze a pipe even in a heated home. Seal small gaps with caulking or spray foam. Sealing drafts also helps you lower your heating bill this winter.
Know where your main water valve is
Find the main shut-off valve now, make sure it turns, and show everyone in the household where it is. In an emergency, every minute counts.
During a Cold Snap
When extreme cold is in the forecast, a few extra habits make a big difference.
- Keep the heat on. Avoid turning the thermostat down too far at night or when you are out.
- Open cabinet doors under sinks on exterior walls so warm air reaches the pipes.
- Let a tap drip slightly on pipes that have frozen before. Moving water is less likely to freeze and it relieves pressure.
- Keep the garage door closed if water lines run through it.
- Keep interior doors open so heat circulates to colder rooms.
If You Leave Home for the Winter
Snowbirds and cottage owners face a higher risk because problems can go unnoticed for days or weeks. Before leaving:
- Leave the heat on at a moderate setting rather than turning it off.
- Shut off the main water supply and drain the lines if the home will be empty for a long time.
- Ask someone to check the property regularly.
- Consider smart water leak sensors or a temperature alert device that notifies your phone.
- Check your home insurance policy; many insurers have conditions about vacant homes and regular inspections.
Connected sensors are one of the practical ways smart technology is changing modern homes.
Prevention Methods Compared
| Method | Best for | Effort |
|---|---|---|
| Draining outdoor taps | Every home with exterior faucets | Low, once a year |
| Foam pipe insulation | Pipes in unheated spaces | Low |
| Sealing drafts | Pipes near exterior walls and vents | Low to moderate |
| Heat cable | Very exposed pipes | Moderate; follow instructions |
| Leak and temperature sensors | Vacant homes, cottages, rentals | Low after setup |
| Dripping taps | Extreme cold nights | Very low |
What to Do If a Pipe Freezes
If you turn on a tap and only a trickle comes out, a pipe may be frozen.
- Keep the tap open so water can flow once the ice melts.
- Find the frozen section, usually in a cold area or along an exterior wall.
- Warm it gently with a hair dryer, a portable heater kept at a safe distance, or warm towels.
- Never use an open flame, such as a torch or barbecue lighter. It is a fire hazard and can damage the pipe.
- If you cannot find or reach the frozen section, call a licensed plumber.
What to Do If a Pipe Bursts
- Shut off the main water valve immediately.
- If water is near outlets or electrical panels, stay away and call an electrician or your utility.
- Take photos and videos of the damage.
- Call a plumber, then your insurer, and start removing water to limit damage.
- Tenants should notify their landlord right away.
Winter prep does not stop at the house. Our winter car checklist helps you get your vehicle ready too.
FAQ: Frozen Pipes
At what temperature do pipes freeze?
Water freezes at 0°C, but pipes in insulated, heated areas usually only freeze during prolonged, much colder weather. Pipes in unheated spaces or exposed to drafts are at risk sooner.
Does letting a tap drip really help?
Yes. A slow drip keeps water moving and relieves pressure in the line, which reduces the chance of a burst.
Is frozen pipe damage covered by home insurance?
It depends on your policy and the circumstances. Many insurers expect reasonable precautions, especially when a home is vacant. Check your policy or ask your insurer.
Can I thaw a pipe myself?
Accessible pipes can usually be thawed safely with gentle heat. If the pipe is hidden in a wall or you suspect a crack, call a plumber.