There’s water damage, and then there’s sewage. A burst supply line puts clean water on your floor. A sewer backup puts bacteria, viruses, and parasites on it. The cleanup rules are completely different, and the biggest mistakes happen in the first hour — usually because someone treats sewage like ordinary water and starts mopping.
Here’s what you’re actually dealing with, what to do right now, and what proper cleanup looks like.
Why sewage is a different problem
The restoration industry classifies water by contamination. Category 1 is clean water from a clean source. Category 2 — gray water from washing machines or tub drains — carries some contamination. Category 3 is grossly contaminated water: sewer backups, septic failures, and any floodwater that’s entered from outside, which picks up soil pathogens and runoff on the way in.
Sewage carries the organisms you’d expect — E. coli, salmonella, hepatitis A, norovirus, giardia among them — and they cause gastrointestinal illness, respiratory infection, and skin infection. Exposure doesn’t require drinking it. Contact with broken skin, hand-to-mouth transfer, and droplets in the air during cleanup are all routes in. Kids and pets, who are lower to the ground and less careful about touching things, are at the most risk.
One detail that catches people out: clean-looking water can be Category 3. Gray water that sits for about 48 hours becomes sewage-level contaminated as bacteria multiply. And floodwater in your basement after a hard PNW rain is Category 3 by definition, no matter how clear it looks.
The mistakes that make it worse
Running a shop vac through it. A household wet-vac isn’t sealed for biohazard. It aerosolizes contaminated water and blows fine droplets through the room you’re standing in, then keeps a contaminated tank and hose in your garage afterward.
Fans. Airflow across contaminated water spreads droplets to clean surfaces. Drying comes later, after decontamination — not before.
Mopping and bleaching a porous floor. Bleach on the surface doesn’t reach contamination that’s soaked into carpet pad, drywall, or particleboard. The material looks clean and stays contaminated.
Waiting. Pathogens multiply, contamination wicks further up walls and deeper into flooring, and the cleanup zone grows by the hour. Sewage sitting in a crawl space — common in older Clark County homes — is one of the worst versions, because the confined space and bare soil make everything harder.
What to do right now
Keep everyone out of the affected area, especially kids and pets. Close the door if there is one. If the backup is coming from a floor drain or toilet, stop running water anywhere in the house — every flush and every load of laundry feeds the backup. If sewage is near outlets or appliances, cut power to that area at the breaker, provided you can reach the panel dry. Then make two calls: a sewage cleanup company, and your insurance carrier.
If you must enter briefly — to grab something essential — gloves, boots, and washing thoroughly afterward are the minimum. Anything porous the sewage touched, treat as contaminated until a professional says otherwise.
How professional cleanup actually works
Sewage work follows tighter protocols than ordinary water damage — IICRC S540 biohazard standards layered on top of the S500 water standard. Here’s the sequence we run:
Containment before cleanup
Crews arrive in full protective equipment and seal the affected area with plastic barriers before touching anything. The point is simple: contamination stays where it is instead of tracking through the house.
Extraction and removal
Contaminated water gets extracted with dedicated equipment that’s decontaminated between jobs. Then comes the part homeowners find hardest to hear: porous materials that contacted sewage — carpet and pad, drywall typically up to 24 inches above the contamination line, insulation, particleboard — can’t be sanitized to safe levels and have to go. They’re double-bagged and disposed of as regulated waste. Non-porous surfaces like sealed concrete, tile, and finished wood can be properly disinfected and kept.
Disinfection, drying, verification
Remaining surfaces get cleaned and treated with hospital-grade antimicrobial, with repeat applications and proper dwell times. Then the structure is dried to IICRC standards with the air continuously HEPA-filtered, and the work can be verified with surface testing — documented for your carrier. Skipping steps here is how a room ends up smelling fine in March and making someone sick in June.
Rebuild
What came out goes back: drywall, insulation, flooring, paint. We handle reconstruction ourselves, so the same company that decontaminated the space is the one that rebuilds it.
What insurance covers
Many homeowners policies cover sewer backups only if you carry a sewer backup endorsement — an add-on worth checking for before you ever need it. Coverage also depends on the source, which is why documenting it matters: a city main backing up, a failed septic line, and rain-driven flooding are treated differently by carriers. We document the source and scope from the first hour, submit to your carrier, and bill them directly on covered claims — your out-of-pocket is typically your deductible.
The bottom line
Sewage in your home is a health event. Keep people out, stop adding water, and don’t start cleanup with household equipment. Call TIK Construction at (360) 938-4601 — a real person answers 24/7, and our crews handle Category 3 work under full biohazard protocols throughout Vancouver, Clark County, and the Portland metro.