Frozen Pipes in Toronto: How to Prevent Them and What to Do If It Happens

When temperatures drop below -10°C in Toronto and the GTA, exposed and poorly insulated pipes are at serious risk of freezing. A frozen pipe is bad enough — but when it thaws and bursts, it can dump hundreds of litres of water into your walls and floors in minutes.

Here is what you need to know.

Which Pipes Are Most at Risk?

• Pipes running through unheated garages, crawl spaces, or exterior walls
• Supply lines to outdoor hose bibs (frost-free bibs can still freeze if the interior valve is not shut off)
• Pipes in cabinet areas along exterior walls (under kitchen sinks on outside walls)
• Water service lines that run through shallow or poorly insulated sections of foundation

How to Prevent Frozen Pipes

Before Winter Hits

• Shut off and drain exterior hose bibs using the interior shutoff valve
• Insulate pipes in unheated spaces with foam pipe insulation (available at any hardware store)
• Seal gaps in exterior walls where cold air can reach pipes
• Know where your main shutoff valve is (see our guide) so you can react fast

During Extreme Cold

• Keep cabinet doors open under sinks on exterior walls to let warm air circulate
• Let a thin trickle of water run from the faucet farthest from your water entry point overnight during a deep freeze
• Keep your home heated to at least 13°C even when you are away
• If you are going away for more than a few days, consider shutting off the main water supply and draining the system

If You Already Have a Frozen Pipe

Do not use an open flame. Torches and heat guns have caused house fires when used on pipes inside walls. Do not do it.

Safe thawing methods:

• Hair dryer on low heat, starting from the faucet end and working back toward the frozen section
• Heating pad or warm towels wrapped around the pipe
• Electric pipe heating cable

Keep the faucet open while you work — flowing water helps melt the ice and tells you when it has cleared.

When to Call a Plumber Immediately

Call right away if:

• You cannot locate the frozen section (it may be inside a wall)
• Water is already leaking when you turn the heat back on
• Multiple fixtures have no flow — suggesting a main line freeze
• You hear cracking or see the pipe bulging

Proper Plumbing GTA responds 24/7 to frozen and burst pipe emergencies. Call: 647 206 3327