A sewer backup is different from every other water loss. The water is IICRC Category 3, black water, which carries bacteria, viruses and whatever else went down the drains upstream. It cannot be dried in place, it cannot be cleaned with household products, and anything porous it touched has to leave the house. The job is as much about disinfection and safe disposal as it is about water removal.
Toronto's oldest neighbourhoods, roughly the area south of Eglinton between the Humber and Victoria Park, are served by combined sewers that carry stormwater and sanitary flow in the same pipe. During a heavy storm the pipe fills, and the path of least resistance is your floor drain. The July 2013 and July 2024 storms each produced thousands of basement backup claims across the city. Tree roots, collapsed clay laterals and grease blockages cause the rest, and those can happen in any weather.
Our crews respond 24/7 across Toronto, North York, Scarborough, Etobicoke, Mississauga, Vaughan, Thornhill, Richmond Hill and Markham with full protective equipment, pumps and containment. Our target is to be on site within 60 minutes.
What we do on site
- Set up containment at the basement entry and put the crew in full personal protective equipment before entering.
- Pump and extract sewage and standing water into sealed tanks for proper disposal.
- Remove all porous materials that contacted the water, bag them, and photograph and list each item for the contents claim.
- Pressure wash or scrub the slab, walls and framing to remove residue.
- Apply hospital-grade antimicrobial to all remaining surfaces and run HEPA air scrubbers throughout.
- Set drying equipment, monitor daily, and confirm dry standard before a final antimicrobial pass.
- Complete the Direction to Pay, send the loss report to your insurer, and hand off to Rebuild Pro Contracting for reconstruction.
What should I do if sewage is coming up through my basement drain?
Stop using water in the house. Every flush, shower and load of laundry adds to what is backing up. If you have a cleanout cap on the main line, do not open it. If the backup is caused by a storm, the flow will slow when the rain stops. Keep everyone, especially children and pets, out of the basement. Turn off the power to the basement at the panel if you can do so without contact with the water.
Then call our 24/7 emergency line. Do not try to mop, vacuum or wash the area yourself. Sewage contains E. coli, hepatitis A and other pathogens, and aerosolizing it with a shop vac or a hose makes it worse. Photograph what you can see from the stairs and leave the rest to us.
- Stop all water use in the home until the line is clear
- Keep people and pets out of the affected level
- Cut power to the basement only if the panel is dry and reachable
- Do not run fans, vacuums or a hose on sewage
- Call our 24/7 emergency line and notify your insurer the same day
What has to be thrown out after a sewer backup?
Anything porous that touched the water. That means carpet and underpad, laminate and engineered flooring, drywall and insulation to at least 30 cm above the water line, particleboard cabinets and shelving, upholstered furniture, mattresses, cardboard, paper, and most clothing and soft toys. Solid wood, metal, glass, hard plastic and sealed concrete can be cleaned and disinfected. Appliances that stood in sewage need to be assessed by a technician before they are turned on.
We inventory every item removed with a photo and description so the contents portion of your claim is complete. Homeowners often underestimate contents losses after a backup. A finished basement with a family room and storage regularly produces a contents list worth more than the structural work.
How do you disinfect a basement after sewage?
After everything porous is removed and bagged, the remaining surfaces are pressure washed or scrubbed to remove residue, because a disinfectant cannot work through a layer of sludge. Then we apply a hospital-grade antimicrobial to the slab, block walls, framing and any hard surfaces, and let it dwell for the time on the label. HEPA air scrubbers run during the whole process to capture airborne particles and odour.
Only then does drying begin. Air movers and dehumidifiers bring the concrete and framing to dry standard over 3 to 5 days, and we log readings daily. A final antimicrobial application on the dry surfaces and a HEPA vacuum of the framing finish the job before Rebuild Pro Contracting starts the rebuild.
Does home insurance in Ontario cover sewer backup?
Only if you bought the sewer backup endorsement. It is not part of a standard Ontario home policy. Most insurers offer it as an add-on with its own limit and sometimes with a separate deductible. If you have it, cleanup, tear-out, drying and rebuild are covered up to that limit. If you do not, the cost is out of pocket, which is why we always recommend checking your declarations page before storm season.
Insurers increasingly require a backwater valve to keep the endorsement after a claim. The City of Toronto Basement Flooding Protection Subsidy Program helps cover the cost of installing one, along with a sump pump and downspout disconnection.
How do I stop a sewer backup from happening again?
A backwater valve on the main sanitary line is the single most effective step. It closes automatically when flow reverses. Disconnect downspouts from the sewer so your roof water is not adding to the combined system. If the backup was caused by roots or a collapsed lateral, a camera inspection will show it and the lateral can be repaired or lined. DryFort Waterproofing installs backwater valves and sump systems across the GTA and can walk you through the City subsidy.
Sewer backup is not covered by a standard Ontario home policy. It requires a separate sewer backup endorsement, which most insurers sell with a limit that is often lower than your main dwelling coverage and sometimes a higher deductible. If you have the endorsement, cleanup, disposal, drying and rebuild are covered up to that limit. Check your declarations page or call your broker as soon as the backup happens. We document the source and every removed item, and we bill your insurer directly through a Direction to Pay.
Frequently asked questions
Is it dangerous to be in a house after a sewer backup?
The affected level is. Sewage carries bacteria and viruses that spread on contact and through the air when disturbed. Keep people and pets off that level, close the door, and avoid running the furnace fan if the return air is in the basement. Upper floors are generally fine as long as the basement is contained. Our crew sets up containment on arrival.
Can carpet be saved after a sewer backup?
No. Under the IICRC S500 standard, carpet and underpad that contact Category 3 water are removed and disposed of. There is no cleaning process that reliably makes them safe, and insurers expect them to be replaced. Hard flooring like tile over concrete can usually be cleaned and kept.
Why did my basement back up when my neighbour's did not?
Elevation and plumbing. The lowest fixture on the street floods first, and a house with a floor drain a few centimetres lower than the neighbour's takes the flow. Homes that have already installed a backwater valve are protected. Some newer homes in the same area have separated sewers while older ones are still on the combined line.
Does the City of Toronto help pay to prevent sewer backups?
Yes. The Basement Flooding Protection Subsidy Program offers eligible homeowners a subsidy toward a backwater valve, a sump pump and severing or capping the storm sewer connection, including downspout disconnection. The work must be done by a licensed contractor with the correct permits. Vaughan, Markham and Mississauga run comparable programs.