I posted this question over at terrylove and thought I’d post it here to see if anyone has other ideas.
I’m finishing up my bathroom remodel. I have two baths back to back. They share a wall where most of the plumbing is located. The same plumber (licensed) has worked on both. Both bathrooms were gutted down to the studs. Bathroom #1 was finished two years ago. Bathroom #2 is a work in progress.
Shortly after the rough plumbing was finished in bathroom #2 I started to smell sewer gas from the sink in bathroom #1. It wasn’t a constant smell. It was infrequent, never lasting more than several minutes. The plumber came and checked everything. He couldn’t find anything wrong. He cleaned some “gunk” out of the drain in bathroom #1. I assumed that would take care of the smell. Well, it came back. I posted this info and a picture of the plumbing on terrylove. Turns out that the sink in bathroom #1 is hooked up to a “S” trap, siphoning the water out of the trap. I don’t know how the plumber missed this. I don’t know if he laid out this line or if he hooked the sink up to the existing line.
My problem now is trying to correct it doing the least amount of damage.
The first picture shows the entire wall. Picture #2 shows a closeup of the section in question. Ideally I’d cut the pipe where it joins the fitting by the copper supply line, put a coupling on and go from there. The problem is that the supply line is pressed tight against the pipe making it impossible to slip a coupling onto the pipe. The two solutions suggested so far are, remove the supply line to fix the line or remove the entire section of the drain line starting with the bend coming through the wall. This would require enlarging the hole that the fitting passes through. This wall is a tiled mud wall so I’m trying to avoid doing that. Does anyone see another way to do this?
Thanks,
Matt
Edited 4/16/2008 1:14 pm ET by mattt19
Replies
Don't know if this will work, but the first thing I would try is fabricating a slightly "taller" P-trap under the sink. Instead if connecting the U-shaped part of the trap directly to the elbow part, try to get a couple inches of straight pipe between them. The extra depth/height might prevent the dogleg in your trap arm (inside the wall) from siphoning your trap. You would also need a longer tailpiece. If it works, a half-hour of tinkering might save an ugly open-wall repair.
Try davidmeiland's fix. It could be all you need to do.
However, it looks to me that you could cut just to the left of the supply pipe to fit in a coupling for a straight shot to a new tee into the drain.
Maybe I misread, but I thought the wall was completely closed now....
The wall is still open in bathroom #2 (pictured).
If I cut just to the left of the supply line I still don't see how I could fit a coupling past the pipe. A coupling (the only one I know of) is 2 1/4" wide. The space between the pipe and the wall is 1 1/2". I can't see how it would fit. The coupling is 1 1/2" deep. To fit it between the supply line and the fitting I'd need to cut the pipe at the 90 degree fitting coming through the wall. But then I'd have nothing to attach the coupling to.
I haven't smelled anything for two weeks. With Daves "fix" I might never know if it was fixed. It might be weeks before the smell comes back.
Is their anyway to remove the fitting just to the right of the supply line? Is there any way to remove the pipe from the 90 degree fitting coming through the wall?
If the wall is open, piece o' cake. It would take Plumbill about 15 minutes.
You don't need a coupling in the trap arm. Have a plumber fix it. They may need to cut the copper out of the way, maybe not. Then, use a Pipe Shredder to ream out the hub on the 90 that comes thru the wall, the leftmost fitting in the pic. That will allow them to connect a new piece of straight pipe that runs almost level to the stack. They need to remove the tee in the stack and install a new one higher up.
Que es un "Pipe Shredder"?
http://www.rectorseal.com/index.php?site_id=1&product_id=145
It reams out a previously glued fitting so you can reuse it, which can be a lifesaver. We recently needed to remove a toilet flange from a closet bend under the floor, and install a new one (offset). It was very easy to do it from above with this tool.
Unfortunately $480 for the kit.
What is wanted is not the will to believe, but the will to find out, which is the exact opposite. --Bertrand Russell
Though I see the Pasco Rambit tools are much cheaper.
What is wanted is not the will to believe, but the will to find out, which is the exact opposite. --Bertrand Russell
You've got more than one problem here.
In the first place, if one sink is siphoning the trap of the other dry, your plumber didn't vent things properly. An inspector would probably downcheck this and order a complete re-do if he saw it, but if you're not at that point, there is a less invasive mechanical solution which you can probably do yourself.
The other problem is that you have what looks an awful lot like a cold solder joint on the bottom of the union in this photo:
View Image
That being the case, I think you might as well cut the supply line and re-do it after you've installed a mechanical air-vent on that 1½" line. You'll need a 1½x1½x1½ ABS T-Y fitting and a glue-to-threaded nipple (probably 1½x1¼, but it depends on the size of the mechanical vent), plus the mechanical air vent itself. This is an inexpensive, spring-loaded, one-way air valve which admits air to the drain lines. I don't like them in general, but for an application like this, they can be a lifesaver.
PS--from the look of the work this plumber has done so far, you might want to think about changing plumbers.
Dinosaur
How now, Mighty Sauron, that thou art not brought
low by this? For thine evil pales before that which
foolish men call Justice....
I don't read anything in the original post about one sink siphoning the other. Also, the copper fitting in the pic is a coupling, not a union, and if the lines are pressurized now there would be a leak already if the joint weren't fully soldered. The pic does not seem clear enough to me to say that the soldering is faulty.
All of the fixtures appear to have venting. If the vent above the level of the photo is blocked then the tub or shower could be contributing to the problem, but I still think that replumbing the goofy looking lateral section would be quick and easy, and likely solve it.
the copper fitting in the pic is a coupling, not a union,
Duh, yeah I knew that, sort of, LOL. Sorry David; you have to remember I don't know the English names of half the crâp I have in stock--in French, that dingus is called a 'bague'...which, literally translated means 'ring'.
Oy-vey!
Dinosaur
How now, Mighty Sauron, that thou art not broughtlow by this? For thine evil pales before that whichfoolish men call Justice....
I think your right on. My first thought was a blockage in the existing vent system.Another good thing, since the wall is completely open now, someone can come in and repair the plumber damage to the existing wall stud by sistering on some 2x6 studs to the old 2x4 studs. Another plumber story in the making, they're all over the place, in every state and city. Might also be worth while to find out what holds the sink in place, certainly not the cut wall studs or missing blocking in the wall.
Edited 5/2/2008 2:34 pm by woodway
2 by 4s would be a luxury. All of my interior walls are 2 by 3. There's no room to add wider studs unfortunately. I've beefed up the adjacent studs where I could.
The sink is screwed directly into the mud wall (I have the feeling you're going to tell me this is a problem). The mud wall is 1 1/4 " thick so he told me to skip the blocking.
It depends, if you just want to look at the sink or photograph it then it's probably OK. If you decide to fill the sink with water and maybe lean on it while shaving, then no, it's going to need some stronger support. The wall is compromised as it is cause the "licensed" plumber cut one of your studs to install the drain and furring out the back side of the wall is easy while it's exposed. If you really want a challenge, you could finish the other bath, hang another sink on that wall with the cut stud and then try to fix the studs after one or both sinks fall. Now that's a challenge!
The people at terrylove weren't impressed with the work either (could someone tell me what's wrong with it it?). In his defense, not all of the work is his. The supply lines were existing as was the vent/drain line. I don't know if he hooked up the section in question or merely tied into it. The bathroom was gutted down to the studs so he has no excuse for missing it.
The sink and the shower vent (far right) were using this line prior to the start of renovation in bathroom #2. He tied the bathtub vent (far left) into this line. The toilet has its own vent. I think that the sink on the opposite wall connects to this line somewhere in the ceiling (I'm not at home so I can't check). None of the fixtures have been installed yet. If was after he finished with the rough plumbing in this bathroom that I noticed the smell. The smell only comes from the sink. The sink in bathroom #1 was installed almost two years ago. Prior to this there was never a smell.What's wrong with the amount of solder on the joint? I thought mechanical air joints had to be accessible so they can be repaired if needed. Both walls will be covered with mud and tile. There will be no way (well no easy way) to access the valve if it fails.Any plumber recommendations for Los Angeles?
Edited 4/16/2008 7:03 pm ET by mattt19
Are you saying that there is no sink in use on the other side of the wall in your photo?
Yes there is a sink. It's the one pictured in post #5. There is a sink and a shower in bathroom #1 (finished) that are in use and connected to this vent.
In bathroom #2 (not finished) a tub and sink have been added to this vent. Neither the tub nor sink for bathroom #2 has been connected at this time.
The people at terrylove weren't impressed with the work either (could someone tell me what's wrong with it it?).
In general, it's sloppy and shows a lack of forethought and/or experience. That goofy-looking lateral run is an example. Used three fittings where two would have done the job. Of course, maybe he ran out of the fittings he needed so he just used what he had in the truck....
More specifically, he used a vent stack as a drain. That is possibly the source of your problem right there. That 2" vent stack is handling the air requirements of the tub, the shower, and the sink, as well as trying to drain the sink. Not good. Probably not code, either, for whatever that's worth....
What's wrong with the amount of solder on the joint?
It's not so much the amount--there's too much visible, but that happens sometimes when you're trying to sweat uphill--as the color and texture. It looks dull and crystalised, the usual look of a cold joint. Good sweated joints show a thin rim of bright, shiny solder right at the fitting, with possibly a drool down a vertical pipe. But all the visible solder should be shiny, indicating it was melted completely by a sufficiently heated pipe--and not by the torch flame!-- and then cooled without being disturbed.
I thought mechanical air joints had to be accessible so they can be repaired if needed. Both walls will be covered with mud and tile. There will be no way (well no easy way) to access the valve if it fails.
You're right; they should be accessible. Simplest way is to build an access panel into the wall when you finish it. This can be a tile-covered 'invisible' panel, held in place by magnetic catches or velcro or whatever, or a hinged, wood-panel door, as you prefer. Lots of nice ways to do that....
But I'm getting confused a bit here. You wrote: Turns out that the sink in bathroom #1 is hooked up to a "S" trap, siphoning the water out of the trap. I thought at first you meant to say one sink was siphoning the trap of the other sink dry, but on second look I'm no longer sure.
Where is this S-trap? The sink on the finished side drains through a chromed P-trap, and that goes through the wall into that goofy lateral run over to the 2". Is it the P-trap that is being siphoned dry?
Any plumber recommendations for Los Angeles?
Sorry, no idea. I'm kinda at the other end of the continent....
Dinosaur
How now, Mighty Sauron, that thou art not broughtlow by this? For thine evil pales before that whichfoolish men call Justice....
Dino, there's nothing horribly wrong with the venting, although it might oughta be 2", but I dunno unless I get out a fixture unit table. In any case it's not bad enough to cause the problem unless it's plugged uphill somewhere. There is no wet venting that I can see. I'm not sure if there are fixtures upstairs using the vent riser as a drain, which WOULD be wet venting.
David, I'll defer to you on the venting capacity; you've got the tables and I don't. But don't you think a popper vent stuck in there between the trap and the suction source would prevent that P-trap from siphoning dry? Takes a lot less vaccuum to open an air-valve than to suck 10 cu.in. of water uphill....
Dinosaur
How now, Mighty Sauron, that thou art not broughtlow by this? For thine evil pales before that whichfoolish men call Justice....
I just don't think it's a venting issue. The high water line inside the trap is higher than the bottom of the horizontal piping where it hits the tee. Classic siphon. I also don't think there's a S trap or trap of any kind in the pic, it's just a dogleg.
edit: never used an AAV yet. I don't think it would help in this situation.
Plumbill should be off work by now and home. Dereliction of duty!!
Edited 4/16/2008 10:06 pm by davidmeiland
I constructed a bathroom last fall where the plumber used not one, but two studor vents (air vents) buried in the wall. To comply with code, when I drywalled over the vents, I cut out a square section of DW to expose the vents. The plumbers then installed HVAC louvered metal vent/grill. Didn't look that great, but the BI was happy.
"I am the master of my fate, I am the captain of my soul." Invictus, by Henley.
I've been following this thread and I must admit I'm perplexed. I'm sure some of the responders have more plumbing savvy than I, but I'd be real surprised if just having that short dogleg would cause that trap to siphon. (I wouldn't call that an "S Trap". A trap is formed to hold water at a low point, and that length of pipe won't -- it slopes consistently downwards.) It just isn't long enough, and there wouldn't ordinarily be enough water in it to suck out a whole trap, IMHO. I'd be doing some additional detective work, like trying to see what's going on when the trap is actually siphoning. Shower running? Toilet flushing? Or just sink running? You may just be undervented. Also, have you checked to make sure the vent isn't plugged and is able to move air properly?
Another thought: I've seen cases where hair or some similar stringy material got into a trap and ran over the top and down into the drain causing water to slowly siphon out of the trap just by capillary action. Have you dismantled the trap to make sure it's clean?
Somethin' just don't seem right here.
Mike Hennessy
Pittsburgh, PA
PS: As for the cold joint issue, I can't tell if it's just flux corrosion or a cold joint. Hit it with some emery cloth to see if the solder is smooth and solid. If so, no problem. But if it's pocked and crystalized looking, you may wanna re-do it while the wall is opened up.
I live in Los Angeles and I've used a plumbing company called John K. Keefe Plumbing. 310 274-9888. They always seem to know what they're doing.
Thanks. I'll give them a call
According to the plumbers over at terrylove.com it's an "S" trap. I think a traditional S trap looks more like a sideways S. What makes it a S trap is the angle of the slope connected to the sanitary tee. Section P3105.1 of the IRC covers trap requirements. The slope should only be 1/4" for the distance it travels. I'm not a plumber. I don't know if my explanation makes sense or if it's correct but that's my understanding of what's going on.I checked the trap and it's clean.
I think the leg into the wye at the main stack should be 2" and the vent stack should be 2" as well. The donward line from the trap should be 1.5" and the trap should be 1.25. UBC calls out an increase of one pipe size for the dogleg and its fittings.... I think.A La Carte Government funding... the real democracy.
The "trap arm" is an important part of a drain system. The code-allowed length of the trap arm is based on the diameter of the pipe, sloped at 1/4" per foot. The length must be short enough to allow air to pass from the vent to the trap, with the water passing beneath. If you look at the trap arm length tables, you can see how this works. From the trap 'weir' (the high point) to the vertical drop will not exceed the pipe diameter x 1/4" per foot, if you see what I mean. The 'dogleg' in your situation will cause the trap to siphon, because the drop is greater that 1/4" per foot, to simplify. Imagine a sinkfull of water dumping down that drain- the air from the vent won't make it to the trap weir.I don't see why you couldn't even replace the 90 if you had to. Not a big deal for a plumber or skilled DIY'er.Bill
The plumber came out to look at the trap arm. He says there's nothing wrong with it. He claims that the trap isn't siphoning and the smell isn't from that. I showed him the codes I found. He dismissed them (yes he's a licensed plumber, and he wasn't cheap). He'll fix it if I insist but he thinks I'm crazy. According to him there are several potential problems fixing the pipe. He'll need to cut the sanitary tee out. He'll need to cut several inches of the drain below the tee off. If you look at the picture you'll notice blocking an inch below the tee. The blocking is for the shower pan in the adjacent bathroom. He'll need to remove a portion of the blocking and he's afraid the pan might be damaged. The walls are mud walls. They extend into the stud cavity slightly, conforming to the shape of the pipes. He's concerned that when he runs the new trap arm the mud wall will push it out of alignment with the drain, making it hard to connect. There's also the problem of the supply line limiting access to the trap arm. Neither he nor another plumber I spoke with want to ream out the existing 90 and reuse it.
The trap does not siphon dry. I've tried to make it siphon without any luck. The last two times the sink smelled I removed the trap and checked it. Both times it was full of water. The original plumber (who I won't be using) cleaned a bunch of "gunk" out of the drain the first time he came out. The smell disappeared for two weeks. I smell it now only when I run the water. Someone suggested that soap, hair etc. might have built up in the overflow. I filled the sink with bleach and turned the water on allowing the sink to drain through the overflow hole. It's only been a day but I no longer smell anything when I use the sink. This bathroom is two years old. Prior to construction on the adjacent bathroom, there was never a smell. The bathroom was sparingly used.
Here's my question - given the potential obstacles in replacing the trap arm would you replace it or leave it? I know it's plumbed wrong but I can't get the trap to siphon dry so I'm having doubts that's what's causing the smell.
Thanks for the advice (sorry for the long post)
Matt check to make sure the vent does not back pitch somewhere above the ceiling, if it is backpitched enough it could collect condensation or rain water and create a trap. Effectively eliminating your vent.
Do you still have access to the piping as shown in the first pic?
I didn't read all the posts-------- yes it is an "S" trap as the vent opening is below the top of the trap arm.
“The world is a dangerous place, not because of those who do evil, but because of those who look on and do nothing.” —Albert Einstein
Yes I do. The entire wall is open (bathroom #2).
As Dave suggested use a rambit¯ or whatever brand he linked to---- a drill bit that is designed to remove pipe from fittings.
Then run a new trap arm to a new san-tee that you install at the correct height.
“The world is a dangerous place, not because of those who do evil, but because of those who look on and do nothing.” —Albert Einstein
I'm going out on a limb here because the NSPC isn't my area of expertise. However, judging from the apparent width of the studs the vent piping is all 1 1/2" diameter when 2" is required (?) for two bathroom groups.
2006 NSPC -
12.10.2 Double Bathtubs and Lavatories
Two lavatories and two bathtubs or showers back-to-back may be installed on the same horizontal branch with a common vent for the lavatories and with no back vent for the bathtubs or shower stalls provided the wet vent is 2” in size and the lengths of the tub/shower drains conform to Table 12.8.1
(if I am misreading/misapplying this please correct me!)
Jeff
Before you go any further, eliminate the obvious.
- are all the fitting properly glued and not just "dry-fit" ?
(seen this too many times)
- is the Fernco type coupling properly sealed and tight?
- is it possible that during the renovation of the first bathroom the
DWV pipes were damaged? An errant screw or swing of the hammer may
have damaged the pipe enough to let sewer gas escape. I would give
the area around the shower blocking a very close look.
toolman65
I've checked all the joints and they've been glued and the coupling appears to be sealed correctly.the smell comes (came) only through the sink drain in bathroom number one, nowhere else. And now that the "gunk" is gone and I've poured bleach down the vent holes there hasn't been a smell in two weeks.
The lack of smell and my inability to get the trap arm to siphon make me believe that the illegal drain isn't the culprit.