Water damage in Markham: what we see most
Markham's housing is mostly young. Milliken, Markville, Raymerville and the older parts of Unionville were built in the 1970s and 1980s. Berczy, Wismer, Greensborough, Cornell, Box Grove, Cachet and Angus Glen came in waves from the 1990s through the 2010s. That means poured concrete foundations, sump pits, plastic weeping tile and basements finished within a few years of closing. Unionville's Main Street and Markham Village on Markham Road are the exceptions, with heritage homes from the 1800s and early 1900s on stone and rubble foundations.
The Rouge River and its branches shape the city. The Rouge, the Little Rouge, Bruce Creek and Berczy Creek all flow through Markham toward Toronto and the lake, with the Milne Dam reservoir on the main Rouge south of Highway 7. Neighbourhoods along the valleys in Unionville, Markham Village and Cornell see more groundwater than the flat interior. Markham was hit by the August 19, 2005 storm that flooded basements across the northern GTA, and again by the July 8, 2013 storm, both of which pushed storm sewers past capacity in the older subdivisions.
Markham has one of the highest rates of finished basements and basement suites in the region, which raises the stakes of every water loss. It also has a dense band of condo towers along Highway 7 from Warden to Woodbine and around Markham Centre. The City of Markham has run flood control and basement protection programs since 2005, and the current subsidy for a backwater valve or sump pump changes over time; check with the city before assuming an amount. Winter freeze-thaw cycles on the open, wind-exposed lots of Berczy and Wismer put garage plumbing and exterior hose bibs at risk every January.
Storm sewer surcharge in 1980s subdivisions
Milliken, Markville and Raymerville were built when storm sewers were sized for smaller storms than we now get. In a July cloudburst, the street floods, the sewer surcharges and water enters the basement through the floor drain or the weeping tile connection. A backwater valve would have stopped it. We extract, remove the affected flooring and drywall, disinfect and dry, and give you the documentation your insurer needs for a sewer backup claim.
Basement suites with a second household
Thousands of Markham homes have a legal or informal basement apartment. A supply-line failure or a sump overflow affects the tenant's kitchen, bathroom and bedroom first. Two households, two sets of belongings and often two insurance policies are involved. We separate and inventory the tenant's contents, document the suite independently and help the landlord's adjuster and the tenant's insurer understand who is responsible for what.
Sump pump overflow in Cornell and Box Grove
The newer eastern subdivisions rely entirely on sump pumps to keep groundwater out. When a pump fails during a storm, or a power outage stops it, the pit overflows within an hour and the water spreads across the finished basement. A battery or water-powered backup pump is the standard prevention. If the pit itself is undersized or the drainage was never right, DryFort Waterproofing corrects it after we dry the space.
Heritage foundations in Unionville and Markham Village
The century homes along Main Street Unionville and in Markham Village sit on rubble or fieldstone foundations with no weeping tile at all. Water comes through the joints in spring and after big storms, and old lath and plaster and wide-plank floors soak it up. Drying these materials takes longer and must be done gently to avoid cracking plaster. Our process follows the IICRC S500 standard with slower, controlled drying for heritage finishes.
How fast can you reach Markham?
Our York Region crew reaches Markham by Highway 404, Highway 7, Steeles, Kennedy and McCowan, with the 407 used for calls to Cornell, Box Grove and Greensborough on the east side. We position vehicles so that a Milliken call and a Cathedraltown call get the same response. Our target is to be on site within 60 minutes of your call to the 24/7 emergency line.
Restoration services we provide in Markham
- Sewer BackupSewer backup cleanup for the 1980s streets of Milliken, Markville and Raymerville where storm surcharge is a recurring problem.
- Flooded BasementsFlooded basement restoration for Markham homes with basement suites, handling the tenant's space and the landlord's structure separately.
- Emergency Water ExtractionImmediate extraction after a sump overflow in Cornell, Box Grove or Wismer, before water reaches bedrooms and storage.
- Structural Drying & DehumidificationControlled structural drying for heritage plaster and plank floors in Unionville and Markham Village.
- Mould PreventionAntimicrobial treatment and verified dry-out for Markham basements, where warm summer humidity accelerates mould growth.
- Leak DetectionLeak tracing in the Highway 7 and Markham Centre condo towers, isolating the failed suite or riser before more units are affected.
Markham neighbourhoods we serve
Unionville, Markham Village, Milliken, Cornell, Wismer, Berczy, Greensborough, Box Grove, Cachet, Angus Glen, Buttonville, Markville, Cathedraltown, Raymerville. If you are just outside these, call anyway: crews cover the whole GTA and the dispatcher will give you a real arrival window.
Questions from Markham homeowners
Does Markham offer a backwater valve subsidy?
The City of Markham has funded basement flood protection measures at various times since the 2005 storm, and York Region municipalities differ in what they offer. Check with the City of Markham for the current subsidy, eligibility and permit requirements before you hire a plumber. Subsidies cover prevention work. The restoration after a flood is billed to your home insurance.
Is a flooded basement apartment covered by my home insurance?
The structure and finishes of the suite are covered by your homeowner or landlord policy for a covered cause such as a burst pipe or, with an endorsement, sewer backup or sump failure. The tenant's belongings are covered by their tenant insurance, not yours. If you did not declare the suite to your insurer, coverage can be complicated, so tell us on the first call.
How long does it take to dry a Markham basement after a sump overflow?
Extraction is done the same visit. Structural drying of a typical finished basement takes three to five days with air movers and dehumidifiers running continuously. Larger open-concept basements or ones where water sat for more than a day can take a week. We take moisture readings every day and remove equipment only once the framing and slab test dry under the IICRC S500 standard.
The water came through the foundation of my Unionville century home. What happens next?
We dry the basement first and remove any material that cannot be dried in place. Then, because the source is the foundation itself, our sister company DryFort Waterproofing assesses the stone or rubble wall and recommends drainage or sealing that respects the heritage structure. Rebuild Pro Contracting restores any finishes that had to come out.