Re: Sewer gas smell from crawl space?
Posted by More on May 01, 2002 at 20:49:08:
In response to Re: Sewer gas smell from crawl space?
You don't mention where you live and whether the condo is built in the County or the City and if there is a homeowners association , and if the condo is a private community. The Building Code as it relates to the plumbing system and DWV (Drain Waste Vent) system establishes adequate pipe size and height to prevent mechanical faulting and failure in the pipe as a result of vacuum pressure or siphonong of wter from traps as a result of falling water down three stories from multiple flushes. It is accepted practice in single family dwellings for the DWV soil stack to penetrate the roof, and vent its sewer gas out into the atmosphere. Yes.....the odor you are smelling is sewer gas, and yes it is required to be vented as written in the code book. What you are seeing is the difference in the RESIDENTIAL Code application and the COMMERCIAL Code. You live in a Condo which was built under a Commercial Code because one owner built multiple dwelling units. That owner may have been Partner or owner in the Homeowner Association, or may have been pressured by a Housing Tract Beautification program which chose to not allow unsightly roof vents to penetrate the roofline. Anyway what you have is a community venting of sewer gas into the attic from the pvc, and then additional mushroom shaped vents that are more eye appealing. Usually this ins't an odor problem because the gas is usually lighter than air, and dissipates in the atmosphere. When there is a high pressure front or inversion layer, or humidity, the sewer gas attaches to water molecules and gets heavier and falls into your living space, and offends your nose.

What to do now? Call your City Health Department and ask for an inspector to assess the apparent health hazard, take air samples, and examine the building Permit for Code Violations, assess the indoor air in your dwelling on a normal day and on humid days, and give you a written report that the builder has not constructed a condo that is hazardous to your health..


: There is a sewer gas smell in my house. It seems to come from the crawl space on the 3rd floor. It's worst when we open the door to the roof on the 4th floor; it seems like the pressure changes and causes the bad smell to come out of the plenum vents and the vents in the 3rd floor bathroom.

: We cut a hole in the ceiling of the 3rd floor and had a look around. Sewer gas smell definitely comes out of this hole! Husband noticed that the sewer vent pipe ends in the attic, just stops, no cap, and it's not piped to the outside. There is a mushroom vent that goes to the roof, but the two are not connected.

: I should mention that I'm in a condo, and there are three other units attached to ours-- you can see across them all from the crawl space and all of them have the same setup with the pvc pipe that leads to nowhere.

: This alarmed us, so we had a plumber come take a look. He said the open pipe was legal and to code, and also that what we were smelling wasn't sewer gas.

: I think he's nuts. Unless there is some other name for the gas that comes out of the hole in the floor before you put a toilet on it, or the gas that comes out of a sink drain hole before you put the sink in...it's definitely the same smell.

: The plumber told us we should call pest control. Again, I think he's nuts--the crawl space is right above our bedroom, we have cats and sharp hearing and I really think we would have noticed critters up there. Besides, the smell has been there for at least a year now. We just really started noticing it again when the weather got nice and we opened up that roof door. Wouldn't a dead animal of some kind stop smelling after a while? or smell worse?

: Can anyone offer any advice as to what to do next? DH is patching up the hole in the bedroom ceiling but we can still get up there if we have to.

: Thanks for any advice you can give.




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