11 guides
Sewage and drain backups
What to do when sewage comes back up into the house: what is safe to stay in, what has to be thrown away, who is responsible for the pipe, and what insurance calls it.
It is backing up right now
Stop using water everywhere, and stay out of what came up.
- Is it safe to stay? Close the door on the affected area and keep everyone out of it. Whether you can stay depends on three things: how far it spread, whether it reached the heating system, and whether anyone in the house is immune compromised.
- Backing up into the shower Stop using water. Waste appearing in a fixture you did not flush means the blockage is in the main line leaving the house, not in the toilet, and every drain you run makes it worse.
- A sewer smell, no backup Run water into every drain you rarely use, including the floor drain and the spare bathroom. A dried out trap is the most common cause by a wide margin, and it costs nothing to rule out.
- Septic backing up Stop using water in the house entirely, then call a septic contractor rather than a drain cleaner. A tank that is full or a drain field that has failed pushes everything back inside until someone pumps it.
- Sewage in a crawl space Stay out of it, stop using water, and switch off any ductwork running under the floor. A crawl space does not drain and does not dry, so this is a pump and removal job rather than something that resolves on its own.
It has stopped and the house is contaminated
What comes out, what can be cleaned, and why the pipe still needs fixing.
- What has to be thrown away Porous material that absorbed it goes: carpet and pad, drywall above the line, insulation, particleboard, mattresses, upholstery. Hard non-porous surfaces can be cleaned. The test is whether it can be scrubbed, not whether it looks dirty.
- Cleaning it up safely A small spill on a hard floor, cleaned within hours with the right protection, is a reasonable job to do yourself. Anything that reached carpet, drywall, or more than about ten square feet is not.
- Tree roots in the line Roots do not break a sound pipe. They find a joint or a crack that is already leaking and grow into it, which is why clearing them without fixing the pipe puts you on an annual schedule.
Insurance, and who owns the pipe
What the endorsement covers, where your responsibility ends, and what cleanup costs.
- Who owns the sewer line? In most places the homeowner owns the lateral from the house to the sewer main, including the part under the street, and the city owns the main. Call the sewer authority before you dig, because the boundary genuinely varies.
- Does insurance cover backup? Usually only if you bought the water backup endorsement, which is not in a standard policy and is normally capped well below your dwelling limit. Check your declarations page for the words water backup.
- What cleanup costs Ask for it as two estimates, not one: the cleanup and removal, then the rebuild of what came out. On a sewage job most of the first number is demolition and disposal, which is what makes it cost more than the same volume of clean water.