When the City sewer surcharges during a major storm, water can back up out of the main and push into the lowest fixtures on your property. On most Vancouver houses that is the basement floor drain. Without a valve on the lateral, that flow keeps coming until the storm passes.

A backwater valve is a one way device cut into the main sewer lateral. Waste flows out normally in everyday use. If the City main surcharges, the valve closes on its own and stops reverse flow. The basement stays dry while the storm does what it is going to do.

Most Vancouver homeowners find out about backwater valves the hard way, after the first backup. That event is a cleanup, sewage decontamination, contents replacement, an insurance deductible, and a disclosed incident that follows the property to the next sale. Fitting the valve beforehand is a fraction of that on every one of those lines.

Much of Vancouver’s older housing stock sits on a combined sewer, where storm and sanitary flow share the same pipe. That is why a surcharge event during an atmospheric river can reach any low lying basement rather than only the ones near a creek. Properties in Strathcona, Hastings-Sunrise and the lower parts of Mount Pleasant carry the most risk.

Sewer backup coverage is a separate rider on a home insurance policy, not part of the standard package. Most BC insurers want a valve installed and certified before they will add it. The valve plus the rider together still costs a fraction of one uninsured backup.

What the install actually involves. The standard job is a mainline gate style valve cut into the main sewer lateral between the house and the property line. Mainline placement is the point: it protects the basement floor drain, the basement bathroom, the laundry standpipe and every other fixture downstream in one move, instead of one fixture at a time. We put a sonde on the sewer camera to find the lateral under the yard or driveway, mark the position where it stays reachable for maintenance, and open an access pit over it. Vancouver residential laterals usually sit 4 to 7 feet down. A 24 inch section comes out of the existing pipe, the CSA certified valve goes in with shielded couplings on both sides, and a precast riser brings the maintenance lid up to grade so nobody has to dig to check it again.

Then it gets tested. A water test proves the valve seats and reopens, the City of Vancouver plumbing inspector witnesses it and signs off the permit, and we photograph the install for the property file. Drain rock goes around the valve, native soil goes back in compacted lifts, and the surface gets restored. The permit is in the quote and the stamped certificate of work is emailed at completion. We will send it straight to your broker on request, because most policies want the documentation before they will add the endorsement.

The insurance side. Sewer backup is one of the most common home insurance claims in BC during an atmospheric river, and a standard policy does not cover it. The endorsement is a separate rider, and insurers generally want the same four things before adding it: a certified valve with the City permit and inspection, a documented annual inspection schedule, a working sump pump if the property has one, and no unresolved prior backup claims. Our install package is built for that file. We have worked with adjusters and underwriters at Aviva, Intact, BCAA, Wawanesa, Square One and TD Insurance.