Is your basement at risk?
- The floor drain has ever pushed water up during a storm
- Others on the block have dealt with sewage in the basement
- You have a finished basement with a bathroom at slab level
- Your home predates current code requirements for backflow protection
How the installation is done
- Camera the main to find a good straight section downstream of all basement fixtures.
- Saw-cut and break out the basement slab at that spot.
- Cut the drain and install a normally open backwater valve with an access box that sits flush with the floor.
- Arrange the required inspection before the concrete is replaced.
- Patch the floor and show you how to open the lid and check the flap.
Subsidies and permits
A building permit is usually needed. The City of Vaughan has offered a basement flooding protection subsidy in past years that can cover part of a backwater valve installation; details shift year to year, so confirm eligibility with the City ahead of the job, as some require pre-approval.
With the flap shut against a surcharge, anything you drain indoors is trapped. During a downpour, postpone the washer and keep showers short.
Maintenance
Every spring and fall, lift the lid, make sure the flap swings easily and that nothing has caught on it, and flush with a bucket of water. Our backwater valve care guide walks through it.
What we open up on this job
| Part | Where we find it | What we do |
|---|---|---|
| Clay tile lateral | Pre-1970s streets in Woodbridge and Thornhill | Root cut, camera, spot or full replacement |
| Cast-iron building drain | Houses of the 1950s to 1970s | Scale cut, inspect for cracks and channelling |
| PVC lateral | Most homes from the 1980s on | Clear, locate sags or offset joints |
| Backwater valve | Required in many new builds and retrofits | Open the lid, clean the flap, test the gate |
Signs it is time to call
- All the fixtures go sluggish together
- Water comes up the floor drain when you do laundry
- Toilet bubbles while a sink drains
- Soggy dip in the grass above where the lateral runs
- Roots pulled back on the cable last time
On the truck for this one
- Sectional machine with root cutter
- Hydro-jetter with sewer nozzles
- Push camera with locator sonde
- Receiver to mark depth on the lawn
- Test plugs and ball
Quick answers
Will it stop groundwater flooding?
No; groundwater is a separate problem. The valve just stops sewage returning. Groundwater is handled by weeping tile and a sump pump.
How long does it take?
Most installs are done in a day, but the inspection timing can add a wait before the floor is closed.