A sewage or rotten-egg smell inside the house means septic gas is getting in where it should be sealed out. Normally those gases vent up and out through the roof. A smell near one drain usually means a dried-out trap or a bad seal at that fixture. A smell through the whole house usually means the system is not flowing, because the tank is full or a line is blocked, and the gas is backing up indoors.
A rotten-egg smell drifting through the house is worth tracking down rather than covering up. Septic gas is supposed to travel up a vent pipe and out through the roof, well above anyone’s nose. When you smell it indoors, that gas has found another way in. Here is how to narrow it down.
The quick way to tell
- Smell near one drain only? Often a dried-out trap in a guest bath or a floor drain that rarely runs. Pour a bucket of water down it. If the smell fades, that was it.
- Smell through the whole house? The system is not venting, usually a full tank or a blocked line pushing gas back indoors.
- Worse after running a lot of water, or with slow or gurgling drains? That points at the tank, not a seal.
- Water in the traps and it still smells everywhere? Time to have the system looked at.
What we do
We find the source instead of guessing. An inspection tells us whether it is a dry trap, a vent, a full tank, or a line problem, and we fix the actual cause so the smell does not come back.
If your house smells of sewage, book an inspection.