Frozen or burst pipes in Ontario: what to do, and how the repair works

General guidance for Ontario. Requirements are interpreted by your municipality, so confirm the specifics for your property before you commit to a plan.

A pipe has burst: what to do in the first hour

Shut off the main water valve first. It is usually in the basement where the water line comes into the house, often near the meter. Find it now, before winter, and make sure it actually turns. If water is near outlets, the electrical panel or light fixtures, keep away and shut off power to that area only if you can reach the panel safely.

Call a plumber to repair the pipe, then call your insurer. The Insurance Bureau of Canada advises reporting frozen or burst pipes to your insurer as soon as possible, and most insurers take claims around the clock. Before anything is cleaned up or torn out, take photos and video of every wet ceiling, wall, floor and cabinet.

Renting? Tell your landlord or property manager right away. In a condo, call management first, because the pipe may be a common element. Our condo water damage guide explains who repairs what in that case.

No water, but no leak yet: thawing a frozen pipe safely

If the taps run slowly or not at all on a very cold day, a pipe is likely frozen. The City of Toronto advises checking pipes along exterior walls and where the water service comes through the foundation, then opening a cold tap (the laundry room is a good one) so water can flow as the ice melts.

Warm the pipe with a hair dryer, heating pad or warm towels, and never leave a heater unattended. Never use a blowtorch, propane heater or any open flame: they are fire and carbon monoxide hazards. The City says thawing can take one to six hours. If you still have no water, call a licensed plumber. In Toronto, 311 will look into a no-water call, but if the frozen pipe is on private property the City will tell you to call a plumber, because owners and landlords are responsible for the pipe from the property line into the building.

Watch the pipe closely as it thaws. Ice can split a pipe without any sign of a leak, and the water only shows up once it melts.

Insurance: the freezing condition most people miss

Many Ontario home policies limit cover for freezing damage when the home is left for more than a few days in the heating season. The usual condition is that someone competent checks the home every day to make sure the heat is on, or that the water is shut off and the pipes and appliances drained. Check the wording on your own policy before you travel. The number of days and the exact conditions vary.

A vacant property is treated differently from one that is just unoccupied for a while. In Morgan v. Co-operators General Insurance, an Ontario court upheld the denial of a water damage claim on a Stoney Creek townhouse that had been empty between tenants during renovations, even though the owner's son checked on it regularly. The court found the home was vacant, and occasional visits did not change that. If a house or suite will sit empty between tenants or during a renovation, talk to your broker before it does.

If the furnace or heat pump fails in winter, the Insurance Bureau of Canada advises shutting off the water and draining the pipes until heat is restored. It also notes that insurance generally covers the water damage, but not the cost of repairing or replacing the furnace itself. This is general information, not legal or insurance advice.

Landlords and tenants: who deals with a burst pipe

Under Ontario's Residential Tenancies Act, the landlord has to keep the rental unit and the property in a good state of repair, and the tenant is responsible for undue damage caused wilfully or negligently by the tenant or their guests. In most burst-pipe cases the landlord arranges the repair and then works out with the insurer, and sometimes the tenant, who pays.

Heat is part of the landlord's duty. In Toronto, landlords must keep rental units at a minimum of 21°C from October 1 to May 15. Other municipalities set their own standards in their property standards by-laws, so check yours. Tenants should report drafts, cold rooms and slow taps early, and know who to call after hours.

The riskiest time for a landlord is a suite sitting empty between tenants or during a turnover. Either keep the heat on and have someone check it regularly, or shut the water off and drain the lines, and confirm with your broker what your policy requires.

Drying is step one. The rebuild is step two.

After a burst pipe, a restoration company extracts the water, removes wet drywall, insulation and flooring, and dries the structure. Their job usually ends with open walls. Then comes the rebuild: insulation and vapour barrier on exterior walls, drywall, taping and paint, ceilings, flooring, trim and cabinets.

The rebuild is also the cheapest moment to stop it happening again. With the wall already open, a supply line that ran along a cold exterior wall can often be moved to an interior wall, and air leaks around the pipe, the rim joist or the foundation can be sealed and insulated properly. Closing the wall back up exactly as it was can mean the same pipe freezes the next cold snap.

Before the walls are closed back in

Settle these first and the rebuild goes faster with fewer arguments.

• A moisture reading or drying sign-off showing the framing and subfloor are dry.
• The plumber's repair is finished and tested under pressure, with no other weak spots on the same run.
• The reason the pipe froze is fixed: rerouted, insulated or air-sealed, not just patched.
• Your adjuster has approved the scope, and you know which items are covered and which are upgrades you are paying for.
• Matching flooring, cabinet doors and paint: repair the damaged area only, or the whole continuous run.
• In a rental or condo: access to neighbouring units, building rules for trades, and when tenants or owners can move back in.

For property managers, landlords and owners

A burst pipe in a rental or a multi-unit building usually means more than one ceiling, a tenant who needs to get back in, and an adjuster who wants a clear scope and photos. One contractor who can do the rebuild, keep a photo record at every stage and work to the approved scope saves time for everyone. When a suite is already open, it is often a good time to do the turnover work too.

Canata Construction rebuilds after water damage in houses, condos and rental properties across Toronto, Mississauga, Hamilton, Halton, Niagara and the rest of Ontario. We give itemized written scopes, keep photo records for adjusters, and carry full liability insurance and WSIB coverage.