Keeping Pipes Thawed Through January

In a nutshell

Freezing happens wherever outdoor air can touch a pipe: exterior walls, crawl spaces, garages, unheated porches and the line feeding an outdoor tap. Keep heat around those pipes, stop drafts reaching them, and keep water moving on the coldest nights. That covers most of it.

Working through it

In the fall

1. Close the indoor valve feeding each garden tap and empty the line, frost-free bibs excepted. Our guide to winterizing outdoor taps shows how.
2. Disconnect garden hoses. A hose left on can trap water in even a frost-free tap.
3. Seal gaps where pipes and cables pass through exterior walls, especially at the rim joist in the basement.
4. Wrap any bare pipe in a cold room with split foam tubing.
5. Track down the main valve and turn it a little, to prove it still moves. See finding the main shut-off.

During a cold snap

• Open kitchen and bathroom cabinet doors on outside walls so room heat can reach the pipes.
• On the worst nights, leave the faucet on the coldest run dribbling until morning.
• Keep the thermostat steady day and night; do not drop it sharply.
• Close garage doors if water lines run through the garage.

Going away

Leave the heat on, at a moderate setting. Arrange for a neighbour to pop in regularly. Away for weeks? Closing the main and emptying the pipes is cheap peace of mind.

Clues worth noticing

Watch for:

• One faucet barely running on a frigid morning while the rest flow normally.
• White frost forming on a bare pipe.
• A toilet that refills slowly.
• Bulging or a visible split in a pipe.

If a line is frozen but not leaking, open the tap it feeds and warm the pipe gently, starting at the tap end and working back. Running water helps melt the ice as it thaws.

In Toronto the repeat offenders are rear kitchens in semis, additions perched over crawl spaces, and any bathroom built above a garage. If the same pipe freezes year after year, it needs to be rerouted or protected, not just thawed each time. The frozen pipes page covers those longer-term fixes.

Signals that it needs a licensed plumber

Bring us in when the ice is somewhere you cannot get at, when the pipe has cracked, or when water shows up as things warm. Shut the main valve first; ice can hold back a leak until it melts. A split pipe is a burst pipe repair and should be fixed before water is turned back on.

For homes with recurring freezing, we can look at the routing and insulation and suggest a permanent change. Treated water systems, like a softener in a cold garage, need protection too.