Just about 2 months ago, we renovated our kitchen below our bathroom. We used to opportunity to replace the old galvanized drain pipes and old barrel p trap for our bathtub with pvc. This was done by the plumber sub my contractor uses. Everything went pretty smoothly except for starting a few weeks after I now notice a smell from our shower overflow. The overflow and drain are pvc replaced 12 years ago. I attached some pictures of the pipe layout. We have one big old main vent line. The tub connects to the sink which now connects to the toilet. I’ve cleaned the drains with bleach and it helps but only temporarily. I’m not sure if it’s sewer gas but when I get up on the overflow , it’s got a musty earthy smell. I called my plumber and they didn’t smell anything they said and recommended cleaning my drain. It’s all new drain lines i don’t get it. I’m concerned my p trap is being siphoned. I don’t even know how we’d correct that. Sorry this is a bit of a ramble but any help is appreciated!
Musty smell from shower overflow
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Your photo of the area under the tub (img_5856), shot from above, is not so useful. I can't tell if there is a trap there or not. It looks like there is a trap under the big white frog-looking glare, but I cannot be sure.
Also, how do the two photos relate to each other?
Also, how do the two photos relate to each other?
photo 5856 is the two drains shower( left side of photo) and sink (right side) converging and going into the toilet drain which is in the middle with the waste pipe and vent stack behind.
There is a trap for sure under the tub. The blurry picture is of the trap from behind the tub area. I unfortunately didn’t take a ton of photos during that time because I didn’t expect anything to come of it.
I will see if I can find another of the trap.
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I am not sure there is a proper vent for your trap's trap arm. That can cause siphoning. The maximum trap arm distance for a 1.5 inch pipe under IPC is 6 ft. https://codes.iccsafe.org/s/IPC2018/chapter-9-vents/IPC2018-Ch09-Sec909.1
And that presumes the pipe is properly sloped. The trap arm length is the length of pipe+fittings from the output of the trap U to the wye.
In your new 6866 photo, I presume that the far pipe coming in from the right is the lavatory waste. That would be the source of the wet venting. I think that should be 2 inch pipe.
In the lower left of your photo, where you join the PVC to cast iron, that looks odd.
Do you have septic or sewer.
As a temporary workaround, after a shower, wait a minute, and dribble maybe 2 cups of water down the drain to refill the potentially siphoned-out trap.
If that trap refilling does not stop the odor, for cleaning, try pulling the cover from the overflow, and spray a bleach solution into the overflow pipe. If sewer, you can make it really strong. If septic, you can still do the spraying, but limit the amount of bleach to about 1/4 cup mixed with some water.
To add a vent,
And that presumes the pipe is properly sloped. The trap arm length is the length of pipe+fittings from the output of the trap U to the wye.
In your new 6866 photo, I presume that the far pipe coming in from the right is the lavatory waste. That would be the source of the wet venting. I think that should be 2 inch pipe.
In the lower left of your photo, where you join the PVC to cast iron, that looks odd.
Do you have septic or sewer.
As a temporary workaround, after a shower, wait a minute, and dribble maybe 2 cups of water down the drain to refill the potentially siphoned-out trap.
If that trap refilling does not stop the odor, for cleaning, try pulling the cover from the overflow, and spray a bleach solution into the overflow pipe. If sewer, you can make it really strong. If septic, you can still do the spraying, but limit the amount of bleach to about 1/4 cup mixed with some water.
To add a vent,
We live in the city and have a sewer. There is a big cast iron vent stack and that goes to the waste pipe. The toilet always connected that way they just added a new drain pipe for the toilet but the old galvanized pipes came in on each side of the toilet pipe. Of course I don’t have before pictures.
Not sure pipe sizing. Would an AAV valve behind tub trap help?
WorthFlorida
Clinical Trail 5th session completed 4/24/24.
Measuring developed length and fixture units
I'm converting from a tub/shower to a large (72" x 72") roll-in shower with 2 shower valves and heads -- one standup and one at a bench. The tub used a 1 1/2" drain, and the shower requires 2". But the existing tub drain to the stack can be easily replaced with 2" using the same routing. Two...
terrylove.com
You may be right that the trap is being siphoned. Where it the vent for the tub? Picture 6866?
See if that refilling helps. If it does, that would indicate that the trap was being siphoned.
What does "behind" mean to you? If it means downstream by 3 or more inches, then it would prevent trap siphoning. If behind means upstream, then no.
What does "behind" mean to you? If it means downstream by 3 or more inches, then it would prevent trap siphoning. If behind means upstream, then no.
No vent for tub and no easy way to install. There never was though. It was galvanized pipes and the tub had a drum trap.Measuring developed length and fixture units
I'm converting from a tub/shower to a large (72" x 72") roll-in shower with 2 shower valves and heads -- one standup and one at a bench. The tub used a 1 1/2" drain, and the shower requires 2". But the existing tub drain to the stack can be easily replaced with 2" using the same routing. Two...
You may be right that the trap is being siphoned. Where it the vent for the tub? Picture 6866?
Wondering if AAV would work here?
Sorry behind meant behind tub which is where drain and trap are. The AAV would have to go after the trap correct?
Yes, downstream of the trap.
The pipe from the lavatory may be serving as wet vent.
https://www.iccsafe.org/wp-content/uploads/20-18927_GR_2021_Plumbing_Venting_Brochure.pdf shows venting for IPC, and the picture at the bottom of page 12 is superset of most setups. The distance from the lavatory to the wye is not limited, if I understand correctly.
https://www.homedepot.com/p/ZEP-32-oz-Bleach-Resistant-Sprayer-Bottle-2-0-ZUPRO2/317117997 is a sprayer that claims to be more bleach-resistant than most. So maybe make a bleach solution that is 75% water and 25% bleach. Spray that.
If you don't want to be pulling the cover off of the overflow, you can probably figure out a squeeze bottle with a tube that will fit thru the overflow openings.
The pipe from the lavatory may be serving as wet vent.
https://www.iccsafe.org/wp-content/uploads/20-18927_GR_2021_Plumbing_Venting_Brochure.pdf shows venting for IPC, and the picture at the bottom of page 12 is superset of most setups. The distance from the lavatory to the wye is not limited, if I understand correctly.
https://www.homedepot.com/p/ZEP-32-oz-Bleach-Resistant-Sprayer-Bottle-2-0-ZUPRO2/317117997 is a sprayer that claims to be more bleach-resistant than most. So maybe make a bleach solution that is 75% water and 25% bleach. Spray that.
If you don't want to be pulling the cover off of the overflow, you can probably figure out a squeeze bottle with a tube that will fit thru the overflow openings.
WorthFlorida
Clinical Trail 5th session completed 4/24/24.
Does this tub have a built in overflow?
See post #3.
terrylove.com
See post #3.
Venting a drum trap
If The contractor is doing a kitchen remodel and there's no walls opened up. Me as the plumber come in to hook up the drain and water connections and realize there's a drum trap but obviously not visible vent do I need to open walls or is the drum trap good enough?
terrylove.com
Last edited:
Does this tub have a built in overflow?
See post #3.
Venting a drum trap
If The contractor is doing a kitchen remodel and there's no walls opened up. Me as the plumber come in to hook up the drain and water connections and realize there's a drum trap but obviously not visible vent do I need to open walls or is the drum trap good enough?
Me look at post three?Does this tub have a built in overflow?
See post #3.
Venting a drum trap
If The contractor is doing a kitchen remodel and there's no walls opened up. Me as the plumber come in to hook up the drain and water connections and realize there's a drum trap but obviously not visible vent do I need to open walls or is the drum trap good enough?
Drum trap is gone. That’s what was there for last 70+ years. Tub overflow is in tub. It’s an old cast iron tub. Probably 70+ years old.
A few observations-
I closed the pop up drain overnight and no smell. I opened it about 30 minutes ago and it now smells. It’s odd because when I put my nose to the drain itself it doesn’t seem to smell strongest there (but at the overflow) however, closing the drain seems to contain the smell.
A family member took a bath last night. I also ran water down a few minutes after the last time the toilet was flushed before bed. Then closed the drain. It didn’t seem to help as the smell was there this morning once i opened the drain again .
I ordered some green gobbler enzyme drain cleaner to try incase this is biofilm or bacteria. I also ordered a small endoscopic camera to see if I can see into the p trap .
The plumber who installed is coming tomorrow. Not my typical plumber but at least maybe they can check it out.
My concern is the solution to this. My kitchen is about 95% done and I can’t rip the ceiling and wall open again.
The back of the tub is a closet with an access panel. The p trap connects to the waste pipe in a small visible area there. I’m not sure if I can fit an AAV there or what. I read about a trap primer?
What would be my options for fixing this if it siphons?
I closed the pop up drain overnight and no smell. I opened it about 30 minutes ago and it now smells. It’s odd because when I put my nose to the drain itself it doesn’t seem to smell strongest there (but at the overflow) however, closing the drain seems to contain the smell.
A family member took a bath last night. I also ran water down a few minutes after the last time the toilet was flushed before bed. Then closed the drain. It didn’t seem to help as the smell was there this morning once i opened the drain again .
I ordered some green gobbler enzyme drain cleaner to try incase this is biofilm or bacteria. I also ordered a small endoscopic camera to see if I can see into the p trap .
The plumber who installed is coming tomorrow. Not my typical plumber but at least maybe they can check it out.
My concern is the solution to this. My kitchen is about 95% done and I can’t rip the ceiling and wall open again.
The back of the tub is a closet with an access panel. The p trap connects to the waste pipe in a small visible area there. I’m not sure if I can fit an AAV there or what. I read about a trap primer?
What would be my options for fixing this if it siphons?
Interesting. With the drain open, maybe the overflow riser acts like a chimney allowing flow, and closing the drain stops that air flow.
Did you try spraying bleach solution into the overflow, and have it spread around inside as well as you can?
Have you pulled the linkage out of the overflow and cleaned?
There are two common types if you have a trip lever.
Did you try spraying bleach solution into the overflow, and have it spread around inside as well as you can?
Have you pulled the linkage out of the overflow and cleaned?
There are two common types if you have a trip lever.
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