The bathtub drain smells sour. My teenagers complain that it smells even when the water is running. Here's my investigation so far...

1) Removed a ton of hair from the drain (gross!)
2) Flushed drain with bleach -- smell returned the next day
3) Used baking soda and vinegar -- smell returned the next day
4) Used drano per directions -- smell returned the next day
5) Checked overflow - water runs freely down to main drain.
6) Pulled the drain cover again. There is no P/J trap visible, the drain makes an immediate 90-degree turn. There is no visible water. (And, after all the cleaners, the PVC bend is pristine!)

The home is 10 years old, the bathroom in question is on the second floor. No other drains in the house emit this odor. We have been noticing this odor (sometimes stronger) but fairly steadily for several months. It is not overwhelming, but persistent.

I pulled the chrome ring around the handle, shone a flashlight and sniffed -- it smelled like the brown paper on the drywall, and there was no evidence of mold. (What a relief!) I am pretty confident that there is not a leak.

When purchased last fall, the home had been vacant for a year. My inspector pointed out that the vent stack coming out of the roof was still capped. On his recommendation, we sawed off the vent cap. We are not sure whether the previous owner had any suction or drainage issues due to the still-sealed vent system. We also don't know if having that capped, because it CREATED suction, kept water high enough in the tub exit path to block sewer gasses - that is anyone's guess.

So now finally the question...

A) If there is no J-trap or P-trap to block the sewage smell, what are my alternatives?

B) If my solution was to close the tub-drain after each shower, is there a way to block/close the overflow drain? Closing the bottom drain still allows the smell to come up out of the overflow.

C) Is replacing the drain with a P or J trap something that a homeowner with some power tools can manage? Does it require inspection?

D) And the biggie - once a plumber destroys my kitchen ceiling to access the plumbing, are we talking a 2-hour, or 2-day project?

Finally, if you've had the patience to read all the details, thanks! I'm a single-mom who's not afraid of power tools (built garage shelving, replaced shower valves, run the pressure washer, added electircal outlets/circuts back to the breaker box -- under the supervision of friends who wanted me to learn, but did the work myself). I should be able to answer questions that you experienced plumbers might ask to sort this out.

Hey Suzen,

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A) If there is no J-trap or P-trap to block the sewage smell, what are my alternatives?

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There are few options here. You MUST install a "P" trap on the tub. As it stands now you have a direct connection between your house and the city sewer allowing sewer gas to enter your home. Sewer gas's a health hazard to your family and the methane content makes it explosive.

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B) If my solution was to close the tub-drain after each shower, is there a way to block/close the overflow drain? Closing the bottom drain still allows the smell to come up out of the overflow.

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You could duct tape or block off the inlets located at the bottom of the chrome trip lever plate,(see image). That would close off the overflow and closing the tub drain after you shower will close off the tub drain. But that's just temporary until you can get a trap installed.

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C) Is replacing the drain with a P or J trap something that a homeowner with some power tools can manage? Does it require inspection?

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it won't require that a permit be pulled or a inspection called but you would have to have plumbing skills and tools to cut out the elbo and replace with a "P" trap. Without knowing the material the pipes are made of I can't answer your question.

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D) And the biggie - once a plumber destroys my kitchen ceiling to access the plumbing, are we talking a 2-hour, or 2-day project?

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In my area we are mandated by code to place a access panel behind the drainage so it can be serviced. If you have one the ceiling won't have to come down and if you don't have one one can be cut in. Unless the plumber runs into difficulties the job shouldn't take more the 3 or 4 hours.

I'm both bothered and concerned that the owner capped off the main vent. By doing so he converted every "P" trap in the house to illegal "S" traps. Have the plumber check the vent system and let me kinow what he says. Good luck, Tom

Suzan:

Speedball has answered your questions... I am just wondering about that ptrap...

I want you to flush the toilet and then tell me if you can hear the flushed water through the tub waste pipe..

Further, run the sink in another room... or flush a toilet from another room. IF no ptrap, you should hear the waste flowing down drain line through the tub waste pipe. If tub has ptrap, you should not hear anything... test that, then get back to us.

Certainly sounds like ptrap missing as odor has been such an issue.. but still.. I want you to test and confirm before going further... Mark

Tom, Mark -

Your diagnostic skills are impressive.

I had the kids both flush the nearby toilet, and then the toilet and sink in the adjacent bathroom. Even after multiple flushes, no gurgles or splashes were audible in this tub. I could hear the input lines in the wall refilling the toilet-tank, but nothing that sounded like a gurgle or flush from the tub drain.

My visit to Home Depot netted me a good look at a bathtub drain kit -- with the diagram right on the plastic packet. It looks JUST like what I see. The associate there said that the p-trap would be out 'past' the end of the tub, and not directly under the drain. But, he didn't know how I could find out for sure. Would the trap being too high or too low cause it to fail to hold water, and therefore let the odor back?

By the way -- these same posts on Yahoo answers only generated a bunch of teenagers saying 'I dunno', and 'Use Drano'. It is so nice to know that there are adults and professionals who can describe what they are talking about. Thank you both! ~~ Sue

Hi Sue:

Seems to me that you must have some kind of trap installed... or you would have heard sounds. So that is good thing.

Home depot guy was not exactly right though. The ptrap should be directly under the tub waste and overflow assembly attached to tub (see pic1... no trap attaced in pic (see pic.#2), but should be straight out from under it (if not would be an s-trap (illegal))).

I wonder what state you are in... some states allow drum traps, still (see pic.#3).. these can be a distance away from tub drain and can really collect junk to stink up drain?

Anyway, have you tried to remove the tub waste and overflow assembly yet... see what is on end of that.. (see pic.#4)

My guess at this point is to call in plumber and have him access drain from closet (access panel behind tub??) or ceiling and see what he says here...

Let us know your thoughts... Mark

Simple answer as to whether a trap's installed? Cut a access panel behind the tub waste and see for yourself. Noise, gurgle, or whatever, I still think sewer gas is getting into the tub waste. Let's find out for sure and then we can move on to a repair. Have a great week end, Tom

The home warranty company (American Home Shield) is sending a plumber out 'some time' this week. I pay a $55 service charge, and they call in the estimate to see what (if anything) is covered.

I'm willing to bet that it ends up being a faulty installation, and therefore not covered, and I'll be footing the entire bill myself. BUT, I'm less likely to be suckered if I know a little about what they're talking about -- and you gentlemen have gotten me far ahead of where I was. I'll post an update after the plumber shows up.

In terms of the assembly -- there is no hardware in the overflow line -- the tub stopper is one of the twist-and-drop styles. I removed the cover and poured water down that hole, (5) in my original post. Tried it again, and it just sounds like running water. It doesn't back up into the visible section in the tub drain, either.

Oh, and I'm in Ohio, near Cincinnati.

Have a wonderful weekend, and thanks again. I'll be back on when I have new info.

Something to try while you wait on the plumber and might provide some additional information for you. Pour about 3 cups of water down the drain, no more. Pour slowly. If the odor is abated, that would indicate that you have a trap but have a venting problem.

Guys -
The plumber showed today. He cut an access panel in the next room, and we took a look. There IS a P-trap. It is 'below' the level of the floor -- between the joists. He was surprised that it was glued together, rather than screwed.

There are no leaks -- no evidence of water on the pipe, or in the cavity. They snaked the drain, and pulled out a fairly small wad of stuff -- nowhere close to what I had cleaned out of the top of the drain.

AND, the smell seems to have not changed.

I tried the 3-cup solution (Harold's). The smell did abate with a small amount of water. When the nearby toilet flushed, I *think* the smell came back. (I tried this again after the plumber left with no conclusion.)

If the toilet flush 'suctions' the water out of the P-trap, what would be the cause? Have you ever heard of this?

It's the lowest trap on the upper level, and isn't very 'deep'. What's the solution there? A 'deeper' P-trap? More like a letter 'U'?

Recap --

Upstairs bathtub has sour smell from drain -- after chemical clog-removers, AND snaking the drain, the smell is worse.

There IS a p-trap, located below the tub (between the floor joists). It is dry, no leaks.

We 'think' that the trap is being sucked dry by nearby toilets flushing - possibly due to a clog in the vent stack, or possibly an issue with the placement of the p-trap. One possible solution the plumber made was adding a 'manual vent' -- my online research called it a 'sure-vent'. I also saw some discussion about where to install it.

SO, if I have access to the tub plumbing -- access hole sawn through the wall in the next room, can I safely install a sure-vent in that wall cavity? There is a lot of space, so I think there will be enough air available to allow the vent to pull in air (not like in a small space between two studs.)

OR, can I install a sure-vent under a nearby sink so that it can equalize the system from there? Hmmm, but the sewer smell is NOT coming from the sink, it's only from the tub itself.

My warranty company, because of the way the plumber described the problem, denied coverage. I had expected him to describe a clog, in which case they'd cover at least snaking out the roof vent. But, nope. The plumber reported it as 'unidentified', and the warranty has no coverage for 'investigating'.

I have all PVC piping under the sinks and tub, so sawing into and inserting a sure-vent is a project I am confident that I can handle (I glued a re-routed A/C drain line successfully).

Feedback, please? ~ Sue

Let's find out vif the tub trap gets sucked dry. Give the potty a couple of flushes and listen at the chrome trip lever overflow plate. If you're venting through the trap and it has water in it you will hear a gurgle. If the trap has no water in it you will hear the water from the toilet go down the drain. Your plumber should know this without being told but if the vent through the roof were clogged then adding a AAV,(air admittance vent) to the tub won't help the other fixtures that are being vented by it. If that's the case,( and I'm not too sure the plumber wasn't simply blowing you off) then snaking the vent's the answer, not adding a AAV. Let me know, Tom

Mark, The "real issue" as I se it is that the smell's still there. If she has a typical bath rough then the tub's wet vented through the lavatory roof vent. If that vent's blocked as they seem to think then do you propose to vent the entire bathroom group by adding a AAV to the tub trap? Just wondering, Regards, Tom

Nope... that is why I deleted my post... ;)

Sounds like they need to unclog the vent to me as well.

OK, so sounds like the AAV is not the answer. I wondered myself where he planned to put it. His next suggestion was to tear out the entire wall, and 'look around some more'...

Oh, and the flushed toilet doesn't gurgle, it runs on down. I can't distinguish a specific gurgle sound, but will check it again when I reach home. ** Checked at home, there is NO sound from the adjacent toilet coming up the tub drain. ** When I close the tub-stopper, put some water in the tub and let it trickle down to fill the trap, the smell stops. **

How close to the tub drain SHOULD the vent stack be connected? I followed the drain line past the p-trap and then horizontal as far as I could reach without locating a connection either up or down.

Next step? Having been on the roof myself with power tools, is clearing the vent (or at least checking for clogs) something I can do myself? I have a 15-year-old son who climbs like a monkey, and would be happy to scramble up there for me. Would the single roof vent stack (almost directly over the tub in question) likely be 'straight' down? What if the clog or mess is off on a side-track? How would I (or the trained and expert plumber) find it?

And, once it was located, how would it be cleared?

If all you have is a single roof vent then we have a problem. A single roof vent tells us that all the vents are tied together in the attic aqnd run out in one stack vent. This means the plumber will have to go up in the attic, locate the correct vent, cut it open and snake from the attic. After he will have to reconnect the vent. There's more labor involved in doing it this way so expect a higher labor charge. Good luck, Tom

Tom.
If Susan has a venting problem and the toilet is sucking the tub trap dry, won't the venting problem be in the main stack of the toilet?

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Harold, Go back and read my last post. If all the vents are revented back into a single roof vent then the correct vent will have to be located and cut into b efore she can snake.

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If we've narrowed the advice down to 'snake the right vent'...

Is this something that a DIY'er could do him/herself? Because the vent isn't carrying water, I'm not scared to get up there and cut a section out. I've got the tools and glue to cut a section, and then replace it (adding in connectors). But for the snaking itself...

Would a 'regular' pipe snake do the job, or do I need something more specific?

It's not about being too cheap to call a plumber :-) I find that I really like to do the tasks myself -- when I've got the right tools and instructions.

Since I've already got the wall open... does adding an AAV make any sense in the long run?

Yes, it's something a DIYer can do but you have to be careful. A power snake can hurt you and you can get it stuck in the pipe. Up on the roof is another danger. It depends on the highth of the roof (you said two stories didn't you) and the pitch of the roof. Cutting in through the attic might be a better option safety wise and shouldn't need to snake as far. Just be sure not to step through ceiling. You could even start with a manual snake since this toilet is on the second floor. Describe the pipe lay out in the attic.

Guys -
I've snaked the vent from the roof. We ran 25' of pipe snake down the vent (it made a right turn about 3 feet in, and then we don't know). All 25' went in without hitting a clog. When we cranked it, it turned easily. Pulled it out, and it was still clean, so it never ran into any really yucky stuff.

My next step is to get into the attic and see if I can track which vent it has. The roof vent is over the wall between two upstairs bathrooms -- but it still means that a distant powder room, laundry and kitchen sink all meet up there somewhere.

I haven't yet torn out more of the wall to investigate.

I know it's a strange question but you don't have a furnace in the attic do you?