We live in a 125-year-old
two-story brick house. In the fall and in the spring we notice a
constant odor. It isn't extremely unpleasant but it pungent. When
you walk into our second floor apartment you are struck by it
immediately. Everyone thinks it smells like something different:
toast, feet, a sweet, ripe fruit. I think I notice it more when it
rains. This smell cannot be found anywhere else is in the building,
only in the apartment we live in. I have done a lot of work on the
apartment. I moved the bathrooms from one room to another. In
doing so, I plugged the old drain for the old toilet. Also, I put in
a space heater that I ran the ventilation pipes up through a chimney
flue. I put down vinyl tile in the kitchen and I put a bathroom
ceiling vent in. What could be causing this unpleasant odor?-anon,
New York
Unwanted odors are
probably one of the most common indoor air quality complaints.
Readers play detective with me. What are the facts or more
importantly what are the clues that will allow us (and the apartment
owner) to solve this odor problem?
We
know that it is a very old house. That in of itself is an important
clue in that older houses have a high probability of having had
things done to them and probably multiple times. Old houses have a
checkered history of renovation and maintenance. Renovations may
have been done professionally or by an owner “handyman” with the
latter being more common. As such some type of renovation that was
not up to professional standards somewhere along the way is highly
likely. Plumbing comes to mind. Maintenance is also, in the main, a
homeowner responsibility.
We
know that the odor has been characterized as something like toast,
feet (ugh) or sweet ripe fruit. Note that sulfury or sewer gas was
not used suggesting that it is not a sewer gas problem. Reinforcing
this is the fact that that the bathroom was moved and the toilet
connection was plugged (of course we do not know whether this
occurred before or after the odor became noticeable).
The
very different characterizations of the odor have something in
common. What is it? Are they chemical in nature? Are they
biological? Are they possibly both? What causes the smell of feet?
It has to be biological, since the odor of feet is caused by
bacteria. Toast is biological but not microbial. Ripe sweet fruit is
biological but again not microbial. Could they be smelling something
emanating from a garbage disposal? The sweet smell, could it be
caused by some type of fragrance, associated with soap or fabric
softener? The answer could be, of course yes to both. If this is the
case, one would expect that the source was plumbing in some way.
Another clue is the fact that the owner seems to notice it more
often when it rains. If that is the case, plumbing has to be a
strong suspect. Why is that the case? When it rains gases in sewer
lines can become compressed whether one is on a city sewer or on a
septic tank. When such gases are compressed they are forced to flow
along the path of least resistance. This path is often into the
house through an open trap, uncapped sewer connection or leaking
sewer gas vent line.
Note
that this problem seems to be restricted to the fall and spring.
What is unique about that? Similar outside pressure conditions
maybe? Less frequent activation of the furnace fan and thus pressure
conditions are different from those in summer or winter?
Sounds
like a sewer gas problem without the odor of sewer gas. Can this be
the case? The answer is of course yes. It is commonly the case that
sewer gases associated with laundry areas do not smell sulfury or
septic. They often smell like a combination of somewhat microbial
and sweet (like the fragrance in soaps and fabric softeners).
The answer is?
In order to
identify and remediate the problem one now has to?
October 14, 2005
