Water Damage Restoration: Your First 24 Hours

Water damage is a race against the clock. What happens in the first 24 hours after a pipe bursts, a basement floods or a sewer backs up decides whether you are looking at a few days of drying or weeks of tear-out, mould removal and rebuilding. It also shapes how smoothly your insurance claim goes.

This guide walks Ontario homeowners through the first day, hour by hour: what to do yourself, what to leave alone, and what a professional restoration crew does once it arrives.

Why the first 24 hours matter so much

Water does not sit still. Within minutes it spreads across floors and wicks up into drywall, baseboards and carpet pad. Within hours it swells particleboard, delaminates laminate flooring and starts to stain. Within 24 to 48 hours, in the warm and humid conditions of a closed-up basement, mould can begin to grow on wet drywall and wood.

• Minutes to 1 hour: water spreads to every low point and soaks into porous materials. Furniture legs, boxes and rugs start wicking.
• 1 to 24 hours: drywall softens, laminate and engineered flooring begin to swell, odours start, and contents sitting in water are often lost.
• 24 to 48 hours: mould growth can begin, clean water starts to degrade and bacteria multiply, and repair costs climb quickly.
• After 48 hours: structural materials may need to be removed rather than dried, and the risk of a mould remediation job on top of the water job rises sharply.

The takeaway is simple: every hour you save at the start is money and material you do not lose later.

Step 1: Make it safe (first 15 minutes)

Before you save anything, protect people.

• Stay out of standing water near electricity. If water has reached outlets, baseboard heaters, a furnace or the electrical panel, do not walk through it. If you cannot reach the panel safely and on dry ground, call your local electric utility.
• Turn off the power to wet areas at the breaker panel, but only if the panel and the floor in front of it are dry.
• Keep children and pets away, especially from water that came up through a floor drain or toilet.
• Watch for sagging ceilings. A bulging ceiling holding water can come down suddenly. Stay out from under it.

Step 2: Stop the water (first 30 minutes)

If the water is coming from a supply line, shut off the main water valve. In most Ontario homes it is in the basement or utility room where the water line comes through the foundation wall, often near the water meter. For a single fixture, such as a toilet, sink or washing machine, the shut-off valve is usually right behind or under it.

If the water is from outside, such as a storm, overland flooding or a foundation leak, you cannot turn it off. Focus on safety and on moving belongings up and out of the way.

Step 3: Figure out what kind of water it is

Restoration professionals in North America follow the IICRC S500 standard, which sorts water into three categories. The category decides how the job is done and what can be saved.

• Category 1 (clean water): a broken supply line, overflowing sink or tub, or melting ice. Caught early, most materials can be dried in place.
• Category 2 (grey water): dishwasher or washing machine discharge, or a toilet overflow with urine but no feces. It carries contaminants and needs cleaning and disinfection as well as drying.
• Category 3 (black water): sewer backups, toilet overflow with feces, and flood water from outside. It is heavily contaminated. Porous materials it touches, like carpet, pad, drywall and insulation, usually have to be removed.

Clean water does not stay clean. After a day or two in contact with building materials and dust, Category 1 water can become Category 2 or 3. That is one more reason to start drying quickly.

If water came up through a floor drain during heavy rain, assume it is sewage until a professional says otherwise.

Step 4: Document everything for your insurance claim (first hour)

Good records make claims faster and reduce arguments later. Before you move or throw out anything:

• Take wide photos of every affected room, then close-ups of damaged walls, flooring, furniture and belongings.
• Record a short video walking through the space, showing how high the water reached.
• Photograph the source if you can see it: the burst pipe, failed water heater, backed-up drain or broken sump pump.
• Write down the time you discovered the water and what you did about it.
• Keep damaged items if you can until your adjuster has seen them or confirmed photos are enough.

Then call your insurance company or broker to open a claim. Most Ontario home policies cover sudden and accidental water damage, such as a burst pipe. Sewer backup and overland flooding are often separate endorsements, so check what your policy includes. Our insurance claims guide explains how the process works and how we bill insurers directly.

Step 5: Protect your belongings (first few hours)

• Move electronics, documents, photos and valuables to a dry floor.
• Lift furniture off wet carpet and put aluminium foil or wood blocks under the legs to stop staining.
• Pull area rugs off wet floors and hang them to dry if the water was clean.
• Open drawers and cabinet doors so the insides can dry.
• If many items are affected, a professional contents pack-out can inventory, clean and store your belongings while the home is dried. See our contents pack-out service.

What not to do

• Do not use a household vacuum to pick up water. It is an electrical hazard and will ruin the vacuum.
• Do not turn on ceiling fans or lights in a room with a wet or sagging ceiling.
• Do not run fans on sewage or flood water. Blowing air across contaminated water spreads bacteria through the house.
• Do not tear out drywall or flooring on your own before it is documented. Your adjuster may need to see it.
• Do not wait to see if it dries on its own. Water trapped inside walls and under floors does not dry by itself fast enough to prevent damage.

Step 6: Call a certified restoration company

A household wet-vac and a couple of box fans cannot dry a building. Professional drying uses equipment and measurements you cannot see from the surface. When our crews arrive, the first visit usually looks like this:

1. Inspection and moisture mapping. We use moisture meters and thermal imaging to find where the water went, including inside walls and under flooring.
2. Water extraction. Truck-mounted and portable extractors remove standing water and pull water out of carpet and pad.
3. Removal of what cannot be saved. Contaminated or badly swollen materials are removed and documented for your claim.
4. Drying setup. Commercial air movers and dehumidifiers are placed based on the size of the space and the readings, not guesswork.
5. Daily monitoring. We return to take readings and adjust equipment until every material reaches a dry standard. Most structures take three to five days.

Learn more about our water damage and flood restoration service.

After day one: preventing mould

The best protection against mould is getting the structure properly dry, fast. If materials stay wet beyond 48 hours, or if the water was contaminated, watch for a musty smell, dark spotting on drywall or baseboards, and allergy-like symptoms. Mould on more than a small area should be handled by professionals using containment and HEPA filtration. Our guide on preventing mould after water damage covers this in detail, and our mould remediation service handles it when it has already started.

Frequently asked questions

How long does it take to dry a house after water damage?

Most homes dry in three to five days with professional equipment, once the water source is stopped and standing water is extracted. Dense materials like hardwood, plaster and concrete, or a very large loss, can take longer.

Can I stay in my home during water damage restoration?

Often, yes, if the affected area can be closed off and the water was clean. With sewage, extensive contamination, or no working kitchen or bathroom, it is usually better to stay elsewhere. Many policies include additional living expenses for that.

Will my insurance cover the cost?

It depends on the cause and your policy. Sudden and accidental water damage is commonly covered. Sewer backup and overland flooding usually need specific coverage. Gradual leaks and lack of maintenance are often excluded. Your broker or adjuster can confirm.

Is it safe to clean up a flooded basement myself?

A small amount of clean water caught quickly can be handled with care. Anything that came up through a floor drain, a toilet or from outside should be treated as sewage and cleaned by professionals with protective equipment.

Water damage? Call now, day or night

999 Restoration answers live 24 hours a day with a 60-minute target response across Southern Ontario, including Toronto, Mississauga, Brampton, Oakville, Burlington, Hamilton, St. Catharines, Niagara Falls, Kitchener and London. See all locations, or call +1-888-999-0292 and a restoration manager will be on the line in seconds.