Category: Prevention Tips

Every winter, deep cold snaps send Mississauga temperatures well below -15°C, and that’s when frozen and burst pipes spike across the GTA. Water expands about 9% when it freezes, building enough pressure to split copper, PEX and plastic lines. The damage usually shows up when the pipe thaws and water pours out. The good news: most frozen pipes are preventable. Use this checklist before winter hits.

Fall Checklist (Do This in October–November)

1. Shut off and drain outdoor taps. Close the interior shut-off valve for each exterior hose bib, then open the outside tap to drain it. Leave it open.
2. Disconnect garden hoses. A hose left attached traps water in the tap, even “frost-free” ones.
3. Insulate exposed pipes in garages, crawlspaces, cold cellars and unheated areas with foam pipe sleeves.
4. Seal air leaks around pipes where they pass through exterior walls, and around rim joists in the basement.
5. Drain irrigation and sprinkler systems, ideally with a compressed-air blowout.
6. Find your main shut-off valve and make sure it turns. Tag it so everyone in the house knows where it is.
7. Service your furnace, because a furnace failure during a cold snap is a common cause of frozen pipes.

During a Deep Freeze

• Keep the thermostat at 17°C or higher, day and night.
• Open cabinet doors under kitchen and bathroom sinks on exterior walls so warm air reaches the pipes.
• Let a pencil-thin trickle of cold water run from taps on vulnerable lines overnight.
• Keep the garage door closed if there are water lines in the garage.

Going Away for the Holidays?

Many Ontario insurance policies limit coverage for freezing damage if the home is unheated or left unattended for more than a few days. Check your policy. Options include having someone check the house daily, keeping the heat on, or shutting off the main valve and draining the lines. A smart water leak sensor with automatic shut-off is a worthwhile upgrade. See our insurance guide.

How to Tell If a Pipe Is Frozen

• Only a trickle, or nothing, comes out of a tap
• Frost visible on an exposed pipe
• Toilet doesn’t refill
• Strange smells from drains

How to Safely Thaw a Frozen Pipe

1. Open the tap so melting water can flow out and relieve pressure.
2. Apply gentle heat: a hair dryer, heating pad or space heater kept at a safe distance, working from the tap end back toward the frozen section.
3. Never use an open flame or propane torch.
4. If you can’t find the frozen section, or the pipe is inside a wall, call a plumber.
5. Be ready to shut the main valve. A pipe that split while frozen will start leaking as it thaws.

If a Pipe Bursts

Shut off the main valve, turn off power to wet areas, photograph the damage and call for help. Follow our burst pipe emergency guide. Fast extraction and drying prevent mould and keep restoration costs down.

Mississauga homeowners can get up to $10,500 back from the City for flood-proofing their homes, through two programs announced in February 2025: the Basement Flooding Prevention Rebate and the Flood Resilience Rebate. If your basement has flooded before, or you live in an area that saw flooding in the July 2013 or July 2024 storms, these programs are worth knowing about. Program details can change, so always confirm current amounts and rules on the City of Mississauga website before you book work.

1. Basement Flooding Prevention Rebate (up to $7,500)

This rebate helps pay for measures that stop water from getting into your basement in the first place. Eligible work must be done by a licensed professional and can include:

• Backwater valve installation on the main sewer line, which stops sewage from backing up through floor drains
• Sump pump installation
• Downspout disconnection from the sewer system
• Related plumbing work such as capping a foundation drain connection

2. Flood Resilience Rebate (up to $3,000)

This rebate is for homeowners who have already experienced flood damage (on or after July 8, 2013) and rebuild using water-resistant materials, covering up to 50% of eligible costs. Think of it as “build back better”: when your basement is restored after a flood, choosing materials that tolerate water can reduce the damage next time. Examples include:

• Moisture-resistant or cement board instead of standard drywall at the bottom of walls
• Closed-cell spray foam or mineral wool instead of fibreglass batts
• Luxury vinyl plank or tile instead of carpet or laminate
• PVC or composite baseboards instead of MDF

Who Is Eligible?

• Owners of detached, semi-detached, duplex or townhouse homes in Mississauga
• The applicant must be the registered owner; proof is usually your City tax bill
• Work must meet program rules, and some measures need a licensed plumber and permits

How to Apply

1. Read the current program guide on the City of Mississauga website.
2. Get quotes from licensed contractors.
3. Complete the work and keep all invoices and photos.
4. Apply online or by mail with your tax bill, invoices and supporting documents.

Why Prevention Pays

A single sewage backup cleanup in a finished basement can cost $12,000 to $35,000 or more, and many basic insurance policies don’t cover it without a sewer backup endorsement. A backwater valve costs a fraction of that, and the rebate covers a large share. Learn more about water damage costs and insurance coverage.

Already Flooded?

Rebates are for prevention and rebuilding. If water is in your home right now, the priority is extraction and drying to prevent mould. Our team provides 24/7 water damage restoration in Mississauga.

Water damage and mould go together. Mould spores are present in every Mississauga home. All they need to grow is moisture, a food source like drywall paper, wood or carpet backing, and time. After a leak or flood, that time is short: mould can begin growing within 24 to 48 hours, and visible colonies can appear within a week or two. Here’s how to tell if you have a problem and how to stop it.

How Fast Does Mould Grow After Water Damage?

This is why professional water damage restoration in Mississauga focuses on drying fast. Getting materials below their dry standard quickly is the best mould prevention there is.

Signs of Mould After a Leak or Flood

• A musty, earthy smell, especially in basements and closets
• Black, green, grey or white spotting on drywall, baseboards or ceiling
• Paint bubbling or peeling
• Warped baseboards or soft drywall
• Condensation on windows and high indoor humidity (over 60%)
• Allergy-like symptoms that improve when you leave the house

Why Household Fans Aren’t Enough

Box fans move air across the surface, but water hides in wall cavities, under baseboards, inside subfloors and beneath laminate. Surfaces can feel dry while the inside of the wall is still wet. Professionals use moisture meters and thermal cameras to find hidden water, and commercial dehumidifiers pull moisture out of the air so materials can actually dry. Learn more in how long water damage takes to dry.

How Mould Is Prevented During Restoration

1. Fast extraction of standing water
2. Removal of materials that can’t be dried in time (wet insulation, carpet pad)
3. Antimicrobial treatment on framing and exposed surfaces
4. Structural drying with daily moisture monitoring
5. Final moisture verification before walls are closed up

What If Mould Is Already There?

Small spots (under about 1 square metre) on hard surfaces can often be cleaned by a homeowner with detergent and water while wearing gloves and an N95 mask. Larger areas, mould inside walls, or mould after a sewage backup should be handled by professionals using containment, HEPA air filtration and removal of affected materials. Health Canada recommends fixing the moisture source first, because cleaning mould without fixing the water problem doesn’t work.

Does Insurance Cover Mould?

Mould that results from a covered, sudden water loss that was reported promptly is often covered as part of the claim. Mould from a long-term leak or high humidity usually isn’t. See our Ontario insurance claim guide.

Prevent Mould in Your Mississauga Home

• Keep indoor humidity between 30% and 50%. Run a dehumidifier in the basement in summer.
• Use bathroom fans during and 20 minutes after showers.
• Fix drips and leaks right away.
• Keep gutters clear and downspouts pointed away from the foundation.
• Don’t store cardboard boxes directly on basement floors.

Related: flooded basement checklist · water damage cost guide