Pipes freeze in South Georgian Bay every winter. Collingwood sits in the lake-effect snowbelt, and the cold arrives in snaps that drop well below freezing for a few days and then lift. Each snap freezes something in somebody’s house. Here is what to do, in order.
Step one: close the main shut-off
Before you do anything else, close the main shut-off. On town water in Collingwood or Wasaga Beach it is usually where the water service comes through the basement wall, next to the meter. On a private well, switch the well pump off at its breaker.
The reason is the thaw. Ice in a pipe rarely splits it at the ice. Water expands as it freezes, the plug traps pressure between itself and a closed tap further along, and the pipe splits in that section. When the plug thaws, the split starts running. With the main closed, a thawed split leaks a little. With it open, it floods.
Step two: find the frozen section
If one tap has no water and the others work, the frozen section is on the line to that tap. If nothing works, it is near where the water comes in. Frozen sections are almost always in one of these places:
- A supply line on an outside wall, especially behind a kitchen sink.
- A crawl space or a cold room.
- A line that runs past a garage or through an unheated addition.
- The service entry, where the water line comes through the foundation.
- On a well, the line from the well where it enters the house.
Step three: thaw it slowly
Open the tap on the frozen line first, so the water has somewhere to go as it thaws. Then warm the pipe:
- Use a hair dryer, a space heater kept well back, or a heat gun on a low setting.
- Start near the open tap and work toward the ice.
- Never use an open flame.
- If the frozen section is inside a finished wall or ceiling, stop and call a plumber. Thawing a pipe you cannot see means not seeing it split.
Step four: check for the split before you trust it
Open the main slowly. Watch the section that froze and the pipe near it. Listen for hissing. On town water, close every tap and read the meter; if it moves, water is going somewhere. On a well, listen for the pump starting with nothing running.
A split in copper runs along the pipe. PEX often survives a freeze, but its fittings may not. Grey Poly-B supply pipe fails at its fittings. Frozen pipe repair cuts out the damaged section and fixes the reason it froze.
When nobody was in the house
Everything above assumes somebody is there when the pipe freezes. In a chalet in The Blue Mountains empty all week, or a cottage closed since October, the water may have run for days before anybody arrives. In that case:
- Close the main, or switch off the well pump, before anything else.
- Switch off power to the area if water has reached lights, outlets or the panel, and only if you can reach the panel dry.
- Photograph everything before cleaning up. Your insurer will ask.
- Check the water heater, the well pump and the pressure tank. They can freeze too.
Stopping it next winter
The freeze always comes back to the same pipe unless its cause is fixed. There are four fixes, from cheapest to most complete:
| Fix | When it fits |
|---|---|
| Pipe insulation | A line that froze only in the worst cold snap |
| Heat trace cable | A line that cannot be moved, in a cold space |
| Re-routing the line | A supply line on an outside wall that freezes every winter |
| Draining the house | A seasonal cottage that stays empty all winter |
For a cottage, draining is the answer. The cottage winterizing guide lists every step, and the shutdown timing note covers when to do it. If the house has Poly-B and it froze, the Poly-B identification note is worth reading before the next winter.