Every winter, thousands of Canadian homeowners deal with the aftermath of frozen pipes — and too often, by the time the damage is discovered, it’s already extensive. A single burst pipe can release hundreds of litres of water into your home before you notice anything is wrong.
The good news: frozen pipes are largely preventable with the right preparation.
Why Pipes Freeze in Canada
Water freezes at 0°C (32°F). But pipes usually don’t freeze simply because outdoor temperatures drop below zero — they freeze when:
- Cold air reaches plumbing through gaps in insulation, foundation cracks, or unheated crawl spaces
- The home is vacant and heat is turned down too low or off entirely
- Wind chill dramatically lowers the effective temperature along exterior walls
- Extended power outages knock out heating during extreme cold snaps
The most vulnerable months are January and February across most of Canada — but early winter cold snaps in November can catch homeowners off guard before they’ve properly prepared.
Which Pipes Are Most at Risk
Not all pipes are equally vulnerable to freezing. The highest-risk locations in Canadian homes include:
- Pipes in exterior walls — especially in older homes with inadequate wall insulation
- Pipes in unheated crawl spaces, attics, or garages
- Pipes under kitchen or bathroom cabinets on exterior walls
- Supply lines to vacation properties left unoccupied during winter
- Outdoor hose bibs — frost-free models reduce but don’t eliminate risk
- Supply lines to outdoor irrigation systems that haven’t been properly winterized
8 Ways to Prevent Frozen Pipes
1. Insulate Vulnerable Pipes
Foam pipe insulation is inexpensive and highly effective. Wrap all pipes in unheated areas — crawl spaces, garages, attics, and rim joist areas — with foam pipe insulation. Pay particular attention to pipes that run along exterior walls.
Estimated cost: $20–$100 DIY for most homes.
2. Seal Air Leaks Around Pipes
Cold air entering through gaps around pipes (where they pass through exterior walls or floors) is a primary cause of winter freezing. Use expanding foam sealant or exterior-grade caulk to close gaps around all pipe penetrations through exterior surfaces.
3. Keep Cabinet Doors Open During Extreme Cold
During extreme cold snaps, open the cabinet doors under kitchen and bathroom sinks on exterior walls. This allows warm air from the heated home interior to circulate around the pipes and prevent temperature drop.
4. Let Faucets Drip During Extreme Cold
Opening a faucet to a slow drip keeps water moving, which makes it significantly harder for pipes to freeze solid. The marginal water cost is trivial compared to the cost of a burst pipe and the damage it causes.
5. Maintain a Minimum Temperature — Even When Away
Never drop your thermostat below 13°C (55°F) when your home will be vacant. Many insurance companies void coverage for freeze damage if the home was improperly heated during the loss. We recommend maintaining at least 16°C throughout Canadian winters for full protection.
6. Disconnect and Drain Outdoor Hoses Before Freeze-Up
Remove all garden hoses from outdoor hose bibs before freeze season — typically by October across most of Canada. Even frost-free hose bibs can freeze solid if a hose is left connected, because the hose traps water in the exposed sill cock section.
7. Drain Irrigation Systems Annually
If you have an in-ground irrigation system, it must be properly winterized before freeze-up — typically by late September to early October in most of Canada. This involves blowing compressed air through all zones to fully purge standing water. An un-winterized irrigation system is one of the most common causes of expensive outdoor plumbing damage.
8. Install a Whole-Home Water Leak Detector
Smart water leak detectors monitor for abnormal water flow and can send phone alerts when a potential leak is detected. Some models integrate with smart home systems and can automatically shut off the main water supply when a burst is detected — minimizing damage dramatically.
What to Do If Your Pipes Freeze
If you turn on a faucet during cold weather and get no water (or just a trickle), you likely have a frozen pipe. Act immediately:
- Keep the faucet open. As the pipe thaws, water and steam need somewhere to escape safely.
- Apply gentle heat. Use a hair dryer, electric heating pad, or warm wet towels applied directly to the frozen section. Always start from the faucet end and work back toward the blockage. Never use an open flame or high-heat tool — this is a fire hazard.
- Check adjacent pipes. If one pipe froze, nearby pipes in the same wall cavity are at equal risk.
- If you can’t locate or safely thaw the pipe — call a plumber.
When to Call a Plumber
Call a licensed plumber immediately if:
- You have no water throughout the entire home (the main line may be frozen)
- You hear sounds of dripping or running water inside a wall or ceiling
- Water stains suddenly appear on walls or ceilings during or after a cold snap
- A pipe has already burst and water is actively flowing
If a pipe bursts: Shut off the main water supply immediately — the shutoff valve is typically near the front foundation wall of your basement or where the main line enters the home — then call an emergency plumber right away.
Our Ottawa plumbers provide emergency residential plumbing service for burst pipes and freeze damage, with fast response to minimise water damage and restore service.
The Cost of Burst Pipes vs. Prevention
| Scenario | Typical Cost |
|---|---|
| Pipe insulation (DIY) | $20–$200 |
| Licensed plumber to inspect & winterize | $150–$400 |
| Thawing a frozen pipe (professional) | $200–$400 |
| Single burst pipe repair | $500–$1,500 |
| Water damage restoration (average claim) | $10,000–$50,000+ |
The math is stark. Spending $200–$400 on prevention and proper winterization can save tens of thousands of dollars in damage — plus the enormous disruption of a major water damage event in your home.
FAQ
At what temperature should I worry about pipes freezing? Pipes typically freeze when temperatures inside unheated spaces drop to -6°C (20°F) or below for extended periods. However, wind chill along exterior walls can cause pipes to freeze even when outdoor temperatures are only slightly below zero — particularly in poorly insulated homes.
Should I turn off the water if my home will be vacant for several weeks? Yes — for extended winter vacancies, shutting off the main water supply and draining the system provides the strongest possible protection. Have your plumber show you how to properly drain the plumbing system, and arrange for a trusted neighbour or property manager to check the home periodically.
Does home insurance cover burst pipe damage? Most home insurance policies cover sudden and accidental water damage from burst pipes — but only if the home was properly heated. Policies typically exclude damage when the home was inadequately heated, left vacant without proper notice to the insurer, or pipes froze due to negligence or failure to winterize.
Can frost-free hose bibs still freeze? Yes, if a garden hose is left connected. The design of frost-free hose bibs moves the internal shut-off back inside the heated wall — but a connected hose traps water in the exposed exterior portion of the sill cock, allowing it to freeze and crack even a frost-free fitting.