Services · Protection
Backwater Valve Installation for Homes Across the GTA
A mainline backwater valve is a flap inside your sewer line that lets waste out and closes when the city sewer surges back. It is the single best defence against sewer backup.
- Water poured through to prove it works
- Pointers on municipal flood-protection programs
- Pit, pump, float and check valve tested together
Diagnosis first, tested after
- Licensed & insured: ask us
- Camera before cutting
- Water-tested repairs
- Booked by phone
Signs it is time to call
If your basement has flooded from a floor drain during heavy rain, if your street has had backups, or if you are finishing a basement, a backwater valve deserves serious thought. Many GTA municipalities have offered subsidies for installing one, often requiring a permit and a licensed plumber. Check the current terms with your city before work starts.
The valve is small. What it keeps out of the basement is not.
On the job, step by step
- Camera the lateral to confirm it is sound and find the right location.
- Pull the permit.
- Break the basement floor over the main drain, usually near the front wall.
- Cut in a normally-open mainline backwater valve with an accessible cleanout lid, set level.
- Pass inspection, then pour concrete and finish flush with an access cover.
We show you how to open the lid, check the flap and clean it once a year.
GTA houses and what they change
The valve must sit downstream of all basement fixtures but some homes have plumbing on both sides of the ideal spot, which changes the layout. Where foundation drains feed the sanitary pipe, that valve may also block that water during a storm, so a sump pump may be needed. Older homes with running traps often have them removed at the same time.
- Do not run water heavily during a storm with the valve closed
- Keep the access lid clear of stored boxes
- Inspect the flap each spring
Before you pick up the phone
Ask whether the quote includes the permit and inspection, whether the valve is a normally-open type, and whether it will qualify for your city’s subsidy. Call (365) 387-8531.
Signs you need this
- 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
What is included
- Check valve and union fittingsStop discharge water falling back into the pit
- Bucket and garden hoseFill the pit to watch the float, switch and discharge
- Typical cause
- Overwhelmed sewers, failed pumps, open laterals
- Access point
- Sump pit, main drain under the floor
- Proof of fix
- Water poured through, valve flap seen closing
Common questions
Will I hear the valve close?
Usually not. It closes silently when water pushes back. That is why it is worth checking the flap periodically.