How it works
- A mainline backwater valve sits in the building drain inside the basement, usually near the front wall. Normally the flap is open and waste flows out. If sewage starts flowing the wrong way, the flap lifts and seals.
- The catch is that while the flap is closed, nothing from upstairs can leave either. While the street sewer is surcharged, the household should use as little water as possible until the sewer subsides.
Installation
- The basement slab is cut and broken out over the main drain, the pipe is exposed, and a section is removed. The valve is set dead level with its arrow pointing to the street, and a flush access lid goes in so the flap can be checked and cleaned. The slab is then patched.
- A plumbing permit is typically required for a backwater valve. We arrange it and the inspection. Some York Region municipalities, including Richmond Hill at various times, have offered subsidies for backwater valves and related flood protection; check the town's current program before work starts, since some require pre-approval.
Signs you need this
- The floor drain has flooded your basement in the past
- Others on your street have had sewage come up
- You are finishing your basement
- Your home is on a low section of the street
- Your insurer has asked about backflow protection
Maintenance
- A backwater valve needs looking at once or twice a year. Lift the lid, check that the flap moves freely and that nothing is caught under it. Grease and debris can hold it open or stuck. We show you how on the day we install.
- If your home has a sump pump or a weeping tile connected to the sanitary line, the backwater valve location must be planned so those connections still drain correctly. We look at that during the assessment.
How the job runs
- 1
The main drain is located and checked on camera.
- 2
A permit is arranged and the slab is opened.
- 3
The valve is installed with an access lid and the slab is patched.
- 4
The inspection is completed and you are shown how to maintain it.
Richmond Hill note: most houses here sit on York Region municipal water with fairly hard supply, and many basements have a floor drain tied to the sanitary lateral. Mention both on the phone; it changes what goes on the truck.
Want a second opinion on your own pipes first? Dial (365) 363-1575; the person answering holds the wrench.