Sewer Smell in the House? Brisbane Diagnostic Guide
A sewer smell inside your home is never normal. In Brisbane's climate, humidity makes it worse fast. Here's how we diagnose it in a typical service call.
1. Dry Floor Waste Trap
Rarely used floor wastes (spare bathrooms, laundries) evaporate their water seal in Brisbane's dry seasons. Pour a cup of water down each to reseal.
2. Failed Wax Ring
Under a toilet — you'll notice it worst in the bathroom. Toilet needs to be lifted and re-set.
3. Missing/Broken AAV
Air-admittance valves under sinks fail after 10+ years, letting sewer gas back into the room.
4. Broken Vent on the Roof
Bird nest or crack in the sewer vent pushes gas back into the house instead of releasing above the roofline.
5. Cracked Sewer Under Slab
Rare but serious. Confirmed with smoke or dye testing.
6. Overflowing Boundary Gully
Outside near the front — if the gully is blocked, gas backs up through every fixture.
Frequently Asked Questions
Is sewer gas dangerous?
Mostly it's just methane + hydrogen sulphide — unpleasant but low risk in ventilated homes. Long-term exposure can cause headaches and nausea.