Unvented old bathroom woes

Hi all! I bought a 1840s farmhouse that was added onto in the 1980s. It has 2 newer bathrooms downstairs and 1 old (but recently refinished) bathroom upstairs. For a while we didn't use the upstairs bath at all, but more recently it has become a Grandma suite and there's frequently a bad, bad septic smell. Running water makes the smell go away, so I assume that trap water is being siphoned off somehow. But then, on further investigation I realized that the upstairs drain is not vented to the roof at all (!) I know both downstairs bathrooms are, however, because I can see the pipes sticking out of the roof. Would this setup normally/possibly be enough to keep a vacuum from developing? Why would they not vent the upstairs bathroom? Were the previous owners possibly smell-impaired? Possibly Informative Tidbits: I have yet to inspect either roof vent to see if they are clogged. The house was largely neglected for at least a decade after kids fled the nest. Question Part B: If this is a condition I need to fix, would an AAV possibly be a good solution to avoid having to add a roof vent. Advice appreciated before I go tearing into walls! (I can post pics as well, but might not help much in this case.) Cheers, GG submitted by /u/greasegum [link] [comments]

Hi all!

I bought a 1840s farmhouse that was added onto in the 1980s. It has 2 newer bathrooms downstairs and 1 old (but recently refinished) bathroom upstairs. For a while we didn't use the upstairs bath at all, but more recently it has become a Grandma suite and there's frequently a bad, bad septic smell.

Running water makes the smell go away, so I assume that trap water is being siphoned off somehow. But then, on further investigation I realized that the upstairs drain is not vented to the roof at all (!) I know both downstairs bathrooms are, however, because I can see the pipes sticking out of the roof.

Would this setup normally/possibly be enough to keep a vacuum from developing?
Why would they not vent the upstairs bathroom?
Were the previous owners possibly smell-impaired?

Possibly Informative Tidbits:

  • I have yet to inspect either roof vent to see if they are clogged.
  • The house was largely neglected for at least a decade after kids fled the nest.

Question Part B:

If this is a condition I need to fix, would an AAV possibly be a good solution to avoid having to add a roof vent.

Advice appreciated before I go tearing into walls! (I can post pics as well, but might not help much in this case.)

Cheers,

GG

submitted by /u/greasegum
[link] [comments]