Hello All,
Situation: 4 story, multi-residential, typical “stacked” bathrooms (common 4″cast waste stacks), no obvious cleanouts visible in suites, (4), 3pc baths in total on that stack with no drainage/toilet issues except as follows….
Symptom: 3rd floor ensuite toilet bowl water level drops by 1/2″ when 4th floor toilet is flushed, but not every time, until toilet trap becomes empty
Remedy: (my approach, too busy/not being equipped to clean long runs)…”call a plumber/drain cleaning co, explain the situation and they will send someone; you might try “
Plumbing”…..one week later I get another call …”
Plumbing was out, put a closet auger down the 3rd floor toilet (5 minutes) and says we don’t clean drains but here’s a bill for 207.00!!! (got refund after nasty call to the serv mgr)
Sequel: I snaked and flushed&
#160;the stack down to 1st floor with my 3/8″ snake and pulled out some hairballs and other lovelys but overall encountered little resistance. Flushed toilet, can hear and feel air intake from roof level…symptom still occurring but not as severe…repeated cleaning 6 times.
One week later, seems to be better but not 100%….any suggestions?? Pull the toilet to access? Bigger snake? Camera down the line?
Thanks
TN
Replies
You got a bald eagle nesting on the vent stack.
ed. Opps, I see you got to the roof already! Maybe he flew away.
Edited 5/10/2008 10:51 am ET by peteshlagor
Did you snake out the vent stack, or just the waste pipe? Sometimes for inexplicable reasons, foreign objects get lodged in vent pipes. I've seen or heard of 'pinkie' rubber balls (kids playing on the roof), chunks of mortar (fell off an adjoining chimney cap), dead birdies (self-explanatory) and once a whonking big clam (which we figure was dropped by a seagull but will never know for sure...).
Sounds to me like there's not enough air getting through the vent when that toilet is flushed. If there was, it wouldn't siphon out the water in the toilet below it. Just because you can hear/feel air intake at the roof doesn't mean there's enough air getting pulled in.
Dinosaur
How now, Mighty Sauron, that thou art not brought
low by this? For thine evil pales before that which
foolish men call Justice....
Edited 5/10/2008 11:17 am ET by Dinosaur
Dino,
Vent stack I assume; accessed/snaked from the roof down. The only one in the vicinity and lines up with the baths below.
Yes, I assumed plugged vent (had been re-roofed recently) was the causing the siphon but seemed to be clear
TN
The only one in the vicinity and lines up with the baths below.
Sounds logical but it is not necessarily a sure indicator; the vent could exit anywhere.
I assumed plugged vent (had been re-roofed recently)
Is there any possibility the roofers roofed right over the vent? What kind of roof is this?
Dinosaur
http://forums.taunton.com/n/mb/message.asp?webtag=tp-breaktime&msg=104375.1
Dinosaur
How now, Mighty Sauron, that thou art not broughtlow by this? For thine evil pales before that whichfoolish men call Justice....
Dino,
Sounds logical but it is not necessarily a sure indicator; the vent could exit anywhere.
OK...true but there are 2 others on the front half of the roof. I can vaguely hear toilet flush in these but the one that I cleaned is right above the bath, can hear/feel it vent instantly and can hear the snake come down the wall behind the baths in all suites below...guess I should try the others to make sure.
Is there any possibility the roofers roofed right over the vent? What kind of roof is this?
Original roof - flat, tar & gravel New roof - 2ply torch-on membrane.....yes but I would think there would be others siphoning/symptoms in other suites if they had roofed over the vent...not that they couldn't have "this pipes in our way...lets cut it off"!!!
Thanks for your replies
TN
2 others on the front half of the roof. I can vaguely hear toilet flush in these
Yeah, check those ones. If you can hear the flush through them, they're connected somehow to that waste stack and if one of them has some roofing crud in it, that reduction in air-supply could be what's causing the problem.
Dinosaur
How now, Mighty Sauron, that thou art not broughtlow by this? For thine evil pales before that whichfoolish men call Justice....
Ok will do....could there be any other explanation in your experience...something in the line or at a junction/"y"/"t" that would allow waste out with no problem yet siphon only 3rd floor toilet with no effect on one above and two below?
TN
If it's really siphoning that is causing the water to disappear from the trap, no.
But if there was a hairline crack in the bottom loop of the S trap in the toilet, that could allow the water to weep or drip out of the trap slowly into the waste pipe so you'd never see it. That's a bit far-fetched, but possible. Your hint would be if the toilet trap empties slowly even when no one is flushing the one above it.
Another WAG that occurs to me is this: does the tenant in the 3rd floor have a cat or a large dog? Cats and dogs have been known to drink out of toilets.
Dinosaur
How now, Mighty Sauron, that thou art not broughtlow by this? For thine evil pales before that whichfoolish men call Justice....
No neither the case here....I witnessed the actual event before cleaning..4th floor flushed 3rd floor toilet bowl water "sloshes" and drops after the flush. Apparently this continues till siphoning enough to drain the trap (over several flushes if the 3rd floor isn't used ie. bowl refilled).
Kinda puzzled on this one...thanks for your advice.
TN
Good luck. Let us know how it turns out.
Dinosaur
How now, Mighty Sauron, that thou art not broughtlow by this? For thine evil pales before that whichfoolish men call Justice....
I am directing this to Plumb Bill as he does plumbing on high rises.I am not sure of the details of how this is done.But you most likely have a main stack that end up at the sewer line on the bottom and the vent at the top.Then at each floor the toilet T's in.Parallel to this you have a vent line that T's in the main stack above the top toilet.And at each floor the vent line connects to the toilet line "someplace".Sounds like the vent connection at this floor is not working correctly.Don't have any idea of suggesting where it connects or how to clean it out or check it..
.
A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
Thanks Bill,
I envisioned what you described as the layout but am unsure what to do next. I have clean/unclogged others with good results but this one has me stumped. Hopefully Plumbbill can advise.
TN
I'm attaching a very rough riser diagram of a went vent stack & a standard system.
The water closet on 4 is forcing positive pressure on the waste stack, that will make the water closet on 3 fluctuate if not properly vented. When the water passes the water closet on 3, it then creates a negative pressure sucking water out of the bowl.
If it is a went vent stack you can use a larger auger as DanH said to help clear any blockage.
If it's a standard system & one of the "re-vents" is clogged that can be a bit more difficult in clearing without opening a wall.
“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
Bill & Dan....first thanks for your replies, taking the time to attach detail and intro to drainage 101 (always learning!!)
Bill....After seeing the "ugly riser diagram" it reminded me of layout examples I'd seen in the plumbing code. Looked it up and and I think the green line in your right hand drawing would be what our code refers to as "branch venting" or separate vent stack tying in above the last bath and how venting requirements change over 3 stories etc...your left hand sketch is basically what I had envisioned (read: rookie!!).
Question: if the vent (green) becomes obstructed (given the layout, I assume this would be rare), there would be no way to access this short of opening walls and augerring the soil stack would not help: correct?
Also, if you could briefly explain the two systems and reasoning as to why/where they would be applied...just curious.
Thanks
TN
Question: if the vent (green) becomes obstructed (given the layout, I assume this would be rare), there would be no way to access this short of opening walls and augerring the soil stack would not help: correct?
Correct, pretty much would have to open the walls to access the vents.
Also, if you could briefly explain the two systems and reasoning as to why/where they would be applied...just curious.
The left drawing is the old standard way of plumbing multi levels.
As codes became more updated systems changed to where every fixture had to have it's own vent, except "wet venting", but that code changed to only allow it on 1 & 2 unit fixtures & they had to be on the same floor----- example would be using the vent of a toilet to drain a lav, which is very common highrise residential construction.
“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
Thanks Bill, interesting....would you recommend first attempting another cleaning with the blade-style auger from the roof down in hopes dislodging the obstruction (if it happen to be conveniently in the vent/soil stack "Y"!!!) ....or skip that and get the "pipe finder" (sawzall) out???
TN
or back to my original response - "I'm really to busy/not equipped to do this...you should contact a drain cleaning Co."
I'd go for the bigger blade auger first, for that is the easiest & cheapest.
Make sure you're on the right stack by having someone flush while you listen to the pipe.
I wouldn't call a drain cleaning co, for they will just do what I said in the first sentance.
How big is the pipe on the roof?
“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
Shouldn't he also pull that toilet and auger that path?.
.
A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
Good point, as a restriction would cause less air flow creating a vacuum.
“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
Bill,
OK I'll try the auger and also pull the toilet.
Stack at roof is 2" cast.
TN
That's a mighty small vent for a soil stack, especially when you consider that code in the US for snow country is that the vent above the roof should be one size larger than inside.
What is wanted is not the will to believe, but the will to find out, which is the exact opposite. --Bertrand Russell
Think you might be jumping the gun a bit. Shouldn't you check to see if it's even a vent problem first? It's quick and easy as I mentioned before.
Is there only one 2" vent for this stack of bathrooms?
If so, then I hope there more vents for other bathrooms & kitchens.
I don't have snow load in my part of the country, but in most jurisdictions the vents must equal the waste going out (cross sectional area)------ in other words if you have a 4" waste leaving the building all the vents combined must equal the cross sectional are of that 4" waste.
Mike makes a good point about shop vacuuming the lav vent.
“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
Sounds like a venting problem. Remove the trap from the lav on the 3rd floor bathroom or, take a shop vac and suck the water out of it. Try flushing now, if it works, it's a vent.
I suspect you have an unvented stack ("wet vent"). Yeah, there's a vent on the roof, but it only really vents the top floor.
It might help to run a rooter type auger through from the roof, to scrape clean the stack all the way down.
Dan,
Not sure I follow, it only vents the 4th floor??? "Wet vent" below that?
It might help to run a rooter type auger through from the roof, to scrape clean the stack all the way down
I believe I have done that unless in the wall or floor there is a cross-over/"t" that"s diverting my auger.
TN
A rooter type auger expands to the size of the pipe and scrapes the walls clean. Your standard auger just punches a hole through the gunk.A "wet vent" is a stack that serves as both vent and drain. Has to be sized larger than a regular stack (or is supposed to be, at least). Probably no longer legal in most areas, especially for a soil stack.If you don't have a wet vent then I'd agree with others that a vent line off to the side is clogged.This is one situation where a leaky toilet would be helpful. I wonder if anyone makes a trap filler for toilets?
What is wanted is not the will to believe, but the will to find out, which is the exact opposite. --Bertrand Russell
Dan,
Yes, after seeing it drawn it makes sense... I 've seen it roughed-in/inside walls during renos like this but never really thought about it.
This is one situation where a leaky toilet would be helpful. I wonder if anyone makes a trap filler for toilets?
Yes, a trap primer for the biffy!!! I was thinking maybe a pin hole placed in the tank flapper or just an 25yr old, cracked AMSTD flush actuator that leaks and "automatically" fills the bowl!!!
TN