Winterizing
Frozen Pipes in Toronto: How to Prevent Them — and What to Do If One Bursts
Toronto winters regularly freeze pipes in exterior walls and unheated basements. How to prevent frozen pipes, spot early warnings, and what to do if one bursts.
Pipes freeze when water inside them sits still in below-zero cold, and Toronto delivers weeks of that every winter. The pipes most at risk are the ones in places your heating barely reaches: exterior walls, crawl spaces, unheated basements, garages, and the hose bib on the outside of the house. A frozen pipe blocks your water at best; at worst it splits, and a burst pipe can put thousands of litres into your home in hours.
How do I prevent frozen pipes in a Toronto winter?
The short version: keep water moving and keep cold air away from pipes. Before winter, disconnect garden hoses and shut off the outdoor water line from inside, then drain it. Insulate pipes that run through unheated spaces — foam pipe sleeves from any hardware store work fine. During deep freezes, open the cabinet doors under kitchen and bathroom sinks that sit against exterior walls so warm air reaches the plumbing, and let a pencil-thin stream of cold water run overnight from the tap furthest from where water enters your home. If you travel in winter, never turn the heat fully off — keep it at 12–15°C minimum.
Older GTA homes — the wartime bungalows in Scarborough, the semis in East York — often have pipes routed through barely-insulated exterior walls, which is why the same houses freeze year after year. If yours is one of them, a plumber can often reroute or properly insulate the problem run in a single visit, which is far cheaper than one burst.
How do I know a pipe is starting to freeze?
One tap slows to a trickle while the others run fine — that's the classic early sign. Frost on a visible pipe, or a faint smell from a drain that's stopped being used, also point to freezing somewhere in the line. Catching it at the trickle stage matters: you can often thaw a pipe safely before it splits.
A pipe burst. What do I do right now?
Shut off the main water valve first — in most Toronto homes it's in the basement, near the floor, on the wall facing the street, close to the water meter. Then open the lowest tap in the house to drain the pressure. Turn off electricity to any area where water is spreading. Then call a plumber on an emergency basis. Take photos for insurance before you start cleaning up.
Frequently asked questions
Can I thaw a frozen pipe myself? If you can see and reach the pipe: yes, gently — a hair dryer or warm towels, working from the tap toward the frozen spot, with the tap open. Never use an open flame, and if the pipe runs inside a wall, that's a plumber job.
What temperature do pipes freeze at? Water freezes at 0°C, but pipes in exposed spots typically become a risk when outdoor temperatures sit below about −6°C for a stretch — a normal Toronto January week.
Does home insurance cover a burst pipe? Usually the water damage yes, the pipe repair itself often no — and insurers may decline claims if the house was left unheated. Check your policy before winter, not after.
Worried about a slow tap or an exposed pipe? Get it looked at before the cold snap — request a plumber or message us on Facebook. GetFixHero connects you with an available GTA pro, free for homeowners.
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