A sewer smell inside the house usually means sewer gas is escaping through a dry drain trap, a failed toilet wax ring, a loose or cracked vent pipe, a broken drain line under the floor, or a fixture installed without a proper trap. Start by running water in every drain; if the smell stays, a smoke test or camera inspection finds the source.
Every drain in your house has a trap, a curved section of pipe that holds water and blocks sewer gas from coming up. The vent pipes on your roof let that gas escape safely outside. When a trap dries out, a seal fails or a pipe cracks, the gas finds its way into the house instead.
What Are the Seven Most Common Causes?
Dry traps
Guest bathrooms, floor drains and unused sinks lose their water seal over time.
Failed wax ring
The seal under a toilet breaks down, often when the toilet rocks.
Vent problems
A cracked or disconnected vent pipe in a wall or attic, or a blocked roof vent.
Broken drain under the floor
Cracked cast iron or a separated joint under a slab or crawlspace.
Missing trap
Laundry standpipes or remodel work done without a proper trap.
Buildup in a drain
Hair, soap and sludge in a sink drain can smell like sewage.
Main line problem
A partial blockage or backup pushing gas up through the lowest drains.
What Can You Check Yourself?
- Run water for 30 seconds in every sink, tub, shower and floor drain, especially unused ones.
- Gently rock each toilet. Movement suggests a failed wax ring.
- Check under sinks for loose connections or missing traps.
- Note when and where the smell is strongest: after showers, on windy days, near one room.
How Do Pros Find a Hidden Source?
A sewer smoke test pushes harmless smoke through the drain and vent system; wherever it appears is where gas escapes. A camera inspection finds cracks and breaks in drain lines. In slab homes, a pressure test confirms leaks under the floor.
Is Sewer Gas Dangerous?
Low levels are mostly unpleasant, but sewer gas can contain hydrogen sulfide and methane. A strong or constant smell should be fixed promptly. If anyone feels dizzy, nauseous or gets a headache, open windows, get outside and call. If it could be natural gas rather than sewer gas, leave and call the gas company first.
What Is Common in Pine Bluff Homes?
In the 1950s and 1960s ranch homes common here, cracked cast iron under the slab is a frequent source, often strongest in a hallway or near a bathroom. In older homes near downtown, vent pipes altered during remodels and never reconnected properly show up often. Both are easy to spot with a smoke test.
Why Does the Smell Come and Go?
Wind blowing across roof vents can pull or push air through the drain system. Changes in air pressure, running exhaust fans and heavy water use all affect how much gas escapes at a given moment. That is why a smell you noticed yesterday may vanish today and return tomorrow. Intermittent smells usually point to a vent, a slow trap leak or a small crack rather than a large break.
See our sewer smell and gas repair service, or read why you smell sewer outside your house. Finding the true source first is how we approach all sewer line repair in Pine Bluff.
Call and my crew will track it down with a smoke test or camera and price the fix before any work. 24/7.
FAQ
Why does my bathroom smell like sewage?
Most often a dry shower or floor drain trap, or a failed toilet wax ring.
Can a sewer smell make me sick?
Low levels usually just smell bad, but strong or ongoing exposure should be avoided and fixed promptly.
Does sewer gas smell like rotten eggs?
Often yes, from hydrogen sulfide. Natural gas also has an added rotten egg odor, so if unsure, treat it as a gas leak.