Key points
- Most backups come from a blocked or damaged sewer line — roots, grease, sagging or broken pipe.
- A backwater valve lets sewage leave the house but blocks it from flowing back in; ask a licensed plumber whether your home suits one.
- A camera inspection shows the condition of your line before it fails.
- Standard homeowner policies usually exclude sewer backup unless an endorsement was added.
Why sewer lines back up
- Tree roots grow into joints in older clay and cast-iron lines. See cast iron drain pipe failure.
- Grease, wipes and debris build up until the line closes.
- Sagging or broken sections collect waste and slow the flow.
- Municipal line problems can push sewage back toward the lowest drain in the house — usually a basement floor drain.
Ways to lower the risk
Backwater valve
A backwater valve is installed in the main sewer line and closes when sewage tries to flow back into the house. Whether one suits your home depends on the plumbing layout and local code — ask a licensed plumber.
Camera inspection and line maintenance
A camera inspection shows roots, cracks and sags before they cause a backup. Vault does sewer line work in-house under the same license: snaking, hydro-jetting, camera inspection, and repair or replacement of damaged sections. See sewer line camera inspection and sewer line services.
What goes down the drain
Keep grease, wipes and paper towels out of drains — they are the most common causes of a blocked line.
Insurance: check for the endorsement
Standard homeowner policies usually exclude sewer backup unless an endorsement was added. The endorsement typically costs $50–$200 a year, with typical limits of $5,000–$25,000. Read more in does homeowners insurance cover sewer backup. General information, not insurance advice.
If it already backed up
Stay out of the water, keep children and pets away, and follow what to do after a sewer backup. In Provo, see sewage cleanup in Provo.
Common questions
Does a backwater valve need maintenance?
Yes. Debris can hold the flap open, so the valve should be checked and cleaned periodically through its access cover, following the manufacturer’s instructions.
Do I need a permit to install one?
Installing a backwater valve on the main sewer line usually needs a plumbing permit. Ask a licensed plumber or your city’s building department.
Does a backwater valve stop every backup?
It protects the drains connected after the valve from sewage flowing back in from the city side. While it is closed, your own wastewater cannot leave either, so avoid running water in the house during a backup. It does nothing about a blockage in your own line, which is why a camera inspection is worth doing.
Sewer line worry or backup?
Call (385) 250-2825 — answered live 24/7 by the Vault crew.