Mystery Odor in Bathroom

[philippo]

Hello, all-

A common problem, I'm sure -- I hope it might have a common solution!

We have an odor showing up in our bathroom, it doesn't smell like sewage but more like the smell one gets when you remove the sink trap for some reason. It pretty well isn't present when one first walks into the bathroom but shows up after we turn on the exhaust fan (whether or not the toilet is used and/or flushed).

I suspect the fan is drawing the odor in from somewhere but I'm not sure. Here are the clues:
1) The bathroom is in a one story part of the house with two 3 outside walls.
2) It is in the very end process of a remodel and the baseboards are not yet in.
3) The crawlspace under it both looks and smells fine.

And perhaps the most telling clue: at the time of the remodel our contractor said the drains (sink, shower, and bathtub) could be vented inside the wall with a studor vent. Being pretty "old school" (used to vents through the roof) I was a bit suspicious but when I crawl underneath it appears that is what he did -- the 3 above drains feed into a single pipe (with appropriate traps in each). "Upstream" from these connections the pipe runs to an outside wall and I can see the bottom of what looks like a 90º elbow turning up just inside the bottom wall plate so it goes through the floor. At this point the vertical pipe is behind a tiled-in pedestal bathtub, where it then is routed into the 2X4 wall and straight up.

I just spoke with my contractor who said he's done this many times with no problem.

Any ideas about where this odor might be coming from?

Thanks!
Philip

 

[CT18]

I my area if a AAV is used it must be accessible for replacement.

 

[KULTULZ]

Hello, all-

And perhaps the most telling clue: at the time of the remodel our contractor said the drains (sink, shower, and bathtub) could be vented inside the wall with a studor vent. Being pretty "old school" (used to vents through the roof) I was a bit suspicious but when I crawl underneath it appears that is what he did -- the 3 above drains feed into a single pipe (with appropriate traps in each). "Upstream" from these connections the pipe runs to an outside wall and I can see the bottom of what looks like a 90º elbow turning up just inside the bottom wall plate so it goes through the floor. At this point the vertical pipe is behind a tiled-in pedestal bathtub, where it then is routed into the 2X4 wall and straight up.

I just spoke with my contractor who said he's done this many times with no problem.

Was the plumbing done to code and was a permit and inspection performed?

At least you know the fan is sized correctly and is drawing...

Click Here- http://www.oatey.com/products/air-admittance-valves/wall-boxes/sure-vent-wall-box

 

[frodo]

code is it SHALL be accessable

shall is one of the words in the code that means the inspector will red tag you in a heart beat if you do not do it

shall means it WILL be done

I would be burning up the phone, calling the builder.

using words like

non code compliant
facebook
angies list
better business bureau
lawyer

but that is just me

 

[phishfood]

Working from just what you have told us, I don't think that the drainage and venting is installed to code.

Was it permitted and inspected?

 

[Mr_David]

Hello, all-


And perhaps the most telling clue: at the time of the remodel our contractor said the drains (sink, shower, and bathtub) could be vented inside the wall with a studor vent. BIG RED FLAGBeing pretty "old school" (used to vents through the roof) I was a bit suspicious but when I crawl underneath it appears that is what he did -- the 3 above drains feed into a single pipe (with appropriate traps in each).You can see the traps in the Crawl. Another RED FLAG "Upstream" from these connections the pipe runs to an outside wall and I can see the bottom of what looks like a 90º elbow turning up just inside the bottom wall plate so it goes through the floor. At this point the vertical pipe is behind a tiled-in pedestal bathtub, where it then is routed into the 2X4 wall and straight up.Start up to where? The roof or an AAV inside the wall.

I just spoke with my contractor who said he's done this many times with no problem. ANOTHER RED FLAG. Licensed contractor??

Any ideas about where this odor might be coming from?

Thanks!
Philip

YOU said you used to have vents through the roof? What happened to those?

Can you post any pictures?

 

[philippo]

I'm curious about a couple of things Mr_David said:

... could be vented inside the wall with a studor vent. BIG RED FLAG
why is this a red flag?

...You can see the traps in the Crawl.
Another RED FLAG
and why is this a red flag?

...where it then is routed into the 2X4 wall and straight up.

Start up to where? The roof or an AAV inside the wall.
"straight" up to an AAV vent inside the wall

...he's done this many times with no problem.
ANOTHER RED FLAG. Licensed contractor??
yes, he is a licensed contractor

YOU said you used to have vents through the roof? What happened to those?
well, they were in a former house (and might even still be there...)

As most of you surmised, my situation is not quite code -- the most unfortunate aspect being that the suspect vent is inside a wall.
If it becomes necessary I could access it from outside, but not easily (I know, I know...)

However, nobody has yet mentioned if a failing AAV vent might even be the source of my problem or how to tell.

And no one has offered any other ideas as to what else it might be...

How about suggestions for a way forward? (rather than my spending all my energy screaming and ranting at everybody else involved...)
Philip

 

[Matt30]

A bad wax seal on your toilet can give you the same smell. Get your sniffer to the base of the toilet and try that. If you get a smell, change the seal.

 

[Mr_David]

Each trap should have it's own vent, not just one at the end.
The vent on each trap is what prevents the trap seal from siphoning out when you run water on the drain.

Originally Posted by Mr_David View Post
... could be vented inside the wall with a studor vent. BIG RED FLAG
why is this a red flag? Studor vent in wall means your contractor does not know how to plumb properly

...You can see the traps in the Crawl.
Another RED FLAG
and why is this a red flag?
What traps are below the floor?
Maybe not a problem if they are only for the tub and or shower.Should only be tub and shower drain traps and maybe a floor drain below floor.

...where it then is routed into the 2X4 wall and straight up.

Start up to where? The roof or an AAV inside the wall.
"straight" up to an AAV vent inside the wall

...he's done this many times with no problem. Is That what he told you? It must be Okay then.
ANOTHER RED FLAG. Licensed contractor??
yes, he is a licensed contractor.
Call your local building department and ask them if it's okay to install an AAV inside the wall. You have a licence #? Ask them if it's valid.

Take some pictures and we might be able to tell you what else is wrong with his work.


YOU said you used to have vents through the roof? What happened to those?
well, they were in a former house (and might even still be there...)
Oh, So this is an all new bathroom with all new plumbingI presume.

 

[frodo]

well, mr Phillip.
You said

"However, nobody has yet mentioned if a failing AAV vent might even be the source of my problem or how to tell.

And no one has offered any other ideas as to what else it might be...

How about suggestions for a way forward? (rather than my spending all my energy screaming and ranting at everybody else involved...)
Philip""



to figure out your problem we need more information.
the red flag about p traps in the crawl space, means that you MIGHT have drains with out vents
but to be sure, we need pictures of what you have.
if no vent on traps. the water seal can be compromised by negative pressure in the plumbing system
caused when the toilet is flushed.
we call it back siphon age.
also studor vents with out access are illegal, they can and will fail.

again, without more information I can not give you an answer as to where stank is coming from

 

[stan96]

Mabey the scum line in the trap?

 

[philippo]

To answer some questions; The traps visible in the crawlspace are from the shower and the bathtub, both these drains are at floor level. These drains are also around 30" apart so wouldn't a single vent suffice for both? (That's IF it were properly installed, and I'm beginning to have my doubts...) If and when I get under the house again I will take a camera, though it won't be easy to get any good pictures, the crawelspace is only about 12-14 " under the bathroom.

About the contractor, his major fault was not overseeing his subs sufficiently -- at the time we wanted this job done he could not schedule his regular plumber so he was trying untested plumbers and told us that. The first one was not very good, and after I pointed out that he'd left trash in the crawlspace and a rats-nest of dangling PEX pipes, he was let go. Plumber #2 cleaned up that mess and seemed fine.

When I was in the crawlspace the other day I noticed another thing that looked wrong -- the P-trap for the bathtub was actually installed at about a 45º angle (the trap was pivoted so the pipes that form the "sides" of the U are about 45º from vertical). I cannot begin to fathom why...?. Anyway, the result is that the bottom of the trap is only about 1.5 inches below the horizontal drainpipe, which can't be a sufficient waterseal. I suspect that the first plumber might be the culprit but it should have been noticed and made right at the time. (I know, this is even hard for ME to picture in my mind, and I LOOKED at it just a couple of days ago).

SO, here are my thoughts: I suspect that the above-mentioned P-trap could be one of the problems, improper vents may be another aspect (Studor or other), and yet another may be a failing toilet gasket -- I temporarily sealed around the base of the toilet with electrical tape and the odor decreased pretty substantially - but not altogether. (BTW, I installed the toilet).
Whether or not the AAV vent is failing I will have to access it at some point, which will require a bit of surgery from outside the house.

Though I would still appreciate any thoughts or ideas, at this point (with so many variables), I'm going to call in a plumber and see if I can get back to my own trade, which is cabinetmaking.

Philip

 

[Mr_David]

I hate generals contractors who try to blame sub par contractors for crappy work. Anyway can't see it from here but I hope you get it straighten out.
Good luck. looking forward to a picture or 2.

I used to dabble with some woodworking but my hobbies seem to change a bit over time.
a couple of my creations

 

[frodo]

Nice woodwork David, I see I am not the only person who likes knotty pine

phillip, according to code. each fixture shall have its own vent

their are exceptions. i dont know if yours is or not

sounds like your problem could be the toilet, pull and reset

 

[Titaniumplumber]

AAV's shall be readily accessible. Also if you are going to vent a bathroom group through AAV's the home needs at least one 3" vtr

 

[frodo]

on a 2nd look at this here thread.


wonder if the idiot tied the fart fan into a vent.