"There's a sewage smell and we can't find where it's coming from" might be the most common non-emergency text we get — often within the first month of moving in. The good news: the usual cause costs nothing to fix. The catch: you need to know which cause you have.
The floor drain nobody warned you about
Korean bathrooms are wet rooms: the whole floor drains through a grated hole, and that drain connects to the sewer. What blocks sewer gas is a small water seal (a trap) inside it. If a drain goes unused — a second bathroom, a balcony drain, the floor drain in a laundry room — that water evaporates in a week or two, and the sewer now vents straight into your home.
The test costs one cup of water: pour it into every floor drain in the house, wait a few hours. If the smell fades, mystery solved — make it a routine for drains you rarely use. Long trips are why so many people come home from leave to a smelly apartment.
When the cup of water does not fix it
If the smell survives the trap test, the usual suspects are: a washing machine hose sitting loosely in its standpipe (gas escapes around it), a failed seal under the toilet, or a grease-coated kitchen line that smells even when it still drains. Each has a different fix, and guessing is how people end up paying for the wrong one.
We locate the actual source — smoke-testing drains, checking the toilet seal, scoping the line if needed — and show you. If it is the building stack rather than your unit, that is the management office's problem, and we will help you make that case.
Do this now
- Pour a cup of water into every floor drain, including ones you never use
- Check the washing machine hose sits snugly in its standpipe
- Note WHERE and WHEN it smells worst — mornings? after laundry? one room?
- Still smelly after the trap test? Text us the details
Sounds like your house? Photos beat descriptions — send what you're seeing.