Homeowner notes
A Room-by-Room Checklist for Keeping a Basement Dry
Most basement floods in the GTA trace back to a short list of causes. Work through this checklist before spring melt and storm season.
- Plain steps a homeowner can follow
- Where the DIY part ends and a plumber takes over
- Ontario and GTA details where they matter
- Plumbing facts, no sales pitch
Diagnosis first, tested after
- Licensed & insured: ask us
- Camera before cutting
- Water-tested repairs
- Booked by phone
Outside the house
- Downspouts disconnected from the sewer and discharging a good two metres out from the walls
- Ground sloping away from the walls
- Window wells clear and covered
- Eavestroughs clean
- Driveway and walkways not draining toward the house
Inside the house
- Backwater valve installed and its flap checked
- Sump pump tested with a bucket of water
- Battery backup working
- Floor drain clear and flowing
- Water heater, washing machine hoses and supply lines in good shape
- Valuables stored off the floor in plastic bins
Most flood damage is to things sitting on the floor that could have been on a shelf.
During a storm
Avoid running washing machines and dishwashers or taking long showers if you have a closed backwater valve, since water has nowhere to go. Watch the sump. Keep the floor drain area clear so you can see a backup early.
Ask your municipality
Toronto, Mississauga, Markham, Burlington and other GTA municipalities have offered basement flooding protection subsidies, often covering part of a backwater valve, sump pump or downspout disconnection. Read our guide on municipal flood subsidies and check the current terms.
Insurance
Standard policies may not include sewer backup or overland flooding. See our sewer backup insurance guide and call your insurer to confirm your coverage. For help with any of the plumbing items above, call (365) 387-8531.
Stop and call a plumber if
- Sump pump runs constantly, cycles fast or hums without pumping
- Damp efflorescence along the bottom of foundation walls
- Sewage smell in the basement after rain
Common questions
Do I need both a backwater valve and a sump pump?
They protect against different water: one against sewer backup, one against groundwater. Many homes benefit from both.