Signs you should consider one
- A storm has pushed water up through your floor drain, or a neighbour's.
- Your street has had sewer surcharges in past heavy rain.
- You have a finished basement or plan to finish one.
- Your insurer has asked about backflow protection.
Why it matters here
Mississauga saw serious basement flooding in the July 2013 storm and in later heavy rains. During extreme events, the sanitary main fills quicker than it empties, and the overflow hunts for the lowest opening. Very often that opening is the drain in your basement slab.
How we install it
- We locate the main sewer line inside the basement, typically near the front wall.
- Permits are obtained; the city inspects backwater valve installations.
- The floor is cut, the line exposed and a section replaced with the valve body.
- An access cover is set flush with the floor for future cleaning.
- The floor is patched and the valve is tested before handover.
What moves the bill
How deep the pipe runs, what covers the floor, and how easy it is to reach all count. If the valve sits under a finished room, carpet and subfloor must be lifted. Sump systems connected to the same line may need changes. The city has offered a subsidy toward flood protection work at times; check the current terms on our subsidy note before you plan.
Worth asking
Ask where the access cover will be and how to inspect the flap. Ask what happens to fixtures upstream of the valve during a backup, since you should not run water while it is closed.
What callers want to know
Is there upkeep on the valve?
A little. Lift the cover twice a year and clear anything caught near the flap.
May I run taps while the flap is down?
Avoid it. With the flap down, your own waste water is trapped inside too.