A pipe rarely splits at the exact spot where the ice forms. That surprises plenty of homeowners, but it explains why so many burst lines are discovered on the first mild afternoon after a cold snap rather than in the middle of one. When water freezes inside a supply line, the ice plug itself usually does little harm. The trouble is the water trapped between that plug and a closed tap. As more ice forms, pressure in that short section climbs until the weakest point gives way, which might be a fitting, a soldered joint or a seam in an old length of copper.
While everything stays frozen, the opening is sealed with ice and very little escapes. Once the house warms up or the sun reaches an exterior wall, the ice melts and the line is suddenly running at full household pressure through a gap it was never meant to have.
If a line freezes or splits
If you open a tap during a cold spell and get a trickle or nothing at all, a frozen section is the likely cause. Leave the tap open, since that gives melting water a way out. Warm the suspect area gently with a hair dryer, a space heater kept at a safe distance, or warm towels. Never use a torch or any open flame; besides the fire risk inside a wall cavity, fast heating can damage the pipe and its fittings.
If the pipe has already split, close the main valve first and then open the lowest taps in the house to drain the lines. Water reaching outlets, appliances or the electrical panel is a reason to stay out of that area until the power is safely off. Water from a burst supply line starts out clean, but it can travel a long way under flooring and into wall cavities before it shows, and it does not stay clean for long once it soaks into building materials.
That hidden spread is why drying matters as much as the plumbing repair. A plumber can replace the failed section fairly quickly, yet the subfloor, insulation and drywall around it may stay wet far longer if left to air out on their own. Companies such as Water Damage Restoration Sherwood Park use moisture meters and thermal cameras to work out how far the water travelled, then set up dehumidifiers and air movers until the materials return to normal readings. A damp wall cavity left closed is how a single burst pipe becomes a mould problem months later.
Once the water is off and drying is under way, it is worth asking why that particular pipe froze. A line that froze once will probably freeze again in the next deep cold unless something changes.
Where pipes freeze in prairie houses
Around Edmonton and Strathcona County, cold snaps that push well past minus 30 are a normal part of winter. The heated living space protects most of your plumbing. The lines at risk are the ones sitting at the edges of that heated envelope:
- Supply lines inside exterior walls, especially behind kitchen and bathroom sinks on the north side of the house
- Plumbing in attached garages, including lines feeding a garage sink or a laundry area
- Outdoor faucets and the short run of pipe just inside the wall
- Crawlspaces, cantilevered floors and bump-outs where insulation is thin or has shifted
- Pipes near rim joists in the basement, where cold air can sneak in around the sill plate
Acreage properties add a few more spots: pump houses, lines to outbuildings, and anything connected to a well or cistern that relies on heat tape or a small heater to stay above freezing. A tripped breaker in a shop or barn can go unnoticed for days.
Keeping water moving when the temperature drops
Most of what prevents frozen pipes is simple, and none of it needs tools. Keep your thermostat at a normal setting overnight during a cold snap instead of turning it way down. Open the cabinet doors under sinks on outside walls so warm room air can reach the pipes. On the coldest nights, a tap on an exterior wall left at a thin, steady drip keeps water moving and gives pressure somewhere to go if ice does start to build.
Outdoor faucets deserve attention in the fall rather than in January. Disconnect garden hoses before the first hard frost, because a hose left attached can hold water in the valve body of a frost-free hose bib and defeat the design. With an older faucet that has a separate shut-off inside, close that valve and open the outside tap so it drains.
Gaps that let cold air hit plumbing are worth sealing, and foam pipe sleeves are inexpensive and easy to slip over exposed lines in a garage or unfinished basement. Heat cable can help in specific problem spots if it is rated for the pipe material and installed to the manufacturer’s instructions.
Finally, find your main shut-off valve and make sure it actually turns. In many Sherwood Park homes it sits near the water meter in the basement or utility room. A valve nobody has touched in years can be seized, and learning that during a flood is the worst possible timing.
A house that handles a mild December can still be caught out by a week of extreme cold in February. A few minutes spent on the vulnerable spots before that week arrives costs far less than cleaning up after it.