Swamp Gas Odor in the basement Half bathroom

[HYIU]

Good morning.
Hope all is doing well. I just join the group to find some help regarding swamp gas odor in my basement bathroom.
I'm no plumber. So any advice is appreciated.
Little back info:
I live in a townhouse in Queens NYC. House was fully gut renovated 5 years ago. otherwise the complex is about 40 years old. I have a half bath in the basement. Recently, I've notice there is a built up of swamp gas like odor accumulating inside this basement half bath. I've done all the DIY in regards to cleaning the drain in the sink once to twice a week for about a month. I use house up mixture to homedepot drainer. Nothing seems to work. I did some more digging and notice that the smell isnt really coming up from the drain of the sink or even the toilet.
Its actually coming from the floor. Hmmm. the floor is ceramic tile. I'm not sure if this coming from the seams where my toilet meets the floor or the wall seams where the wall behind the toilet meets the floor. There is no ventilation in this bathroom. So far the smell seems to isolated only in the half bath. But it does seems to be getting worst.
Anyone have any insite as to where this smell might be coming from and how to remedy this problem? I thank you in advance.

 

[HYIU]

Another question, Does swamp gas usually rise up or sinks down?

 

[Jeff Handy]

The smell could easily be from somewhere else in the basement, like a floor drain or laundry sink with a dry trap.

Or a sump pump or ejector pump pit.

Or the sewer line under the floor is broken, and leaking crap water under the slab.

Or the vent behind the wall by the toilet or sink was never finished, a fitting might be missing or not glued.

 

[Twowaxhack]

Reset the toilet.

 

[Geofd]

Two waxhack maybe on to something

 

[frodo]

WINTER, this time of year on this forum we get this question a lot

Find your AC/heating unit. During hot months the AC drips condensate into the ptrap
During cold months the AC is not running and the trap dries out.
short term solution, pour water into the trap
long term. install a trap primer

 

[PerplexedPlumber]

In the winter or during a summer drought, any open drain (including floor drains or underused sinks and toilets will benefit from some added water. You don't need to wait for the sewer gas odor to occur, just do it on a maintenance basis.

 

[Twowaxhack]

In the winter or during a summer drought, any open drain (including floor drains or underused sinks and toilets will benefit from some added water. You don't need to wait for the sewer gas odor to occur, just do it on a maintenance basis.

What about during spring and fall ?

 

[PerplexedPlumber]

OK, so to those who are in AL, maybe there is no difference year-long, but to those of us where the weather changes, we like spring and fall, and we have to pay more attention to humidity and humidity control year-long. Or are you suggesting that toilets and sink drains need to be flushed more often than 3 months for sanitary reasons? I would agree with that; was responding about the cause of leaking sewer gas from drains that no longer have a water seal at a trap. In some parts of the world during dry weather, there isn't enough humidity to keep the water from evaporating at a fast rate, the dryer, the faster.

 

[Jeff Handy]

WINTER, this time of year on this forum we get this question a lot

Find your AC/heating unit. During hot months the AC drips condensate into the ptrap

During winter, maybe the high efficiency furnace drips or pumps condensate water into the same trap.
Or the furnace humidifier creates significant drain water.

 

[Twowaxhack]

The human condition is to forget. So I instruct my customers to develop a routine year round.

I was just pretending to be a customer, that’s the questions would get.

Hence why I say develop a routine year round.

 

[PerplexedPlumber]

Wouldn't it be nice if someone handed you an owners manual when you purchased a house that included information on the drain and vent system and the electrical system, so you didn't have to guess? Maybe I'll get around to that for this house. It is among my best of intentions . . .

 

[Twowaxhack]

Most of our condensate drains extend to the outside. It’s not put into the drainage system.

So the only traps we are concerned with is unused bathrooms and floor drains.

Not many floor drains in homes here. Very few basements. The basements have a sump and a pump and the water goes outside.

A trap will dry out in less than three months here and we have a subtropical climate. AC’s running all day in the summer will dry them quicker. It only has to evaporate enough to break the seal, not go dry.,

So that’s that.

 

[Twowaxhack]

Wouldn't it be nice if someone handed you an owners manual when you purchased a house that included information on the drain and vent system and the electrical system, so you didn't have to guess? Maybe I'll get around to that for this house. It is among my best of intentions . . .

Contractors should be required to submit an as built plan.