Over 698,000 strictly plumbing related posts
Plumbing education, information, advice, help and suggestions are provided by some of the most experienced plumbers who wish to "give back" to society. Since 1996 we have been the best online (strictly) PLUMBING advice site. If you have questions about plumbing, toilets, sinks, faucets, drains, sewers, water filters, venting, water heating, showers, pumps, and other strictly PLUMBING related issues then you've come to the right place. Please refrain from asking or discussing legal questions, or pricing, or where to purchase products, or any business issues, or for contractor referrals, or any other questions or issues not specifically related to plumbing. Keep all posts positive and absolutely no advertising. Our site is completely free, without ads or pop-ups and we don't tract you. We absolutely do not sell your personal information. We are made possible by:
Author:
new2plum (NY)
Hi everybody: I posted this query a few weeks ago and from the searching here it appeared most of thee leaks come from the flashing area, well I can now tell you that my old 1930s vent stack itself is to blame!
Just to give a little background, I have a brownstone one family and there are 3 cast iron/ lead vent stacks protruding through roof. One above the upstairs toilet, one above the upstairs shower and sink and one for the downstairs kitchen/ basement toilet/ sink. The leak is coming from the upstairs vent stack. Please correct and guide me along. all 3 vent stacks appear perfectly vertical without bends.
So I went up again on my flat roof and poured some water inside of the vent stack and the leak appeared on the first floor directly below. The flashing around is 100% fine because I tarred it over before thinking this was the cause and I also put water there to double check- bone dry..
So the vent stack is 4.5 inch diameter. About 2 feet down the pipe gets narrower, then more narrow another half foot down. These two transition points are corroded and one or both are where the leak is.
My question is, is it acceptable to fit a candy cane shaped or half moon plastic or rubber fitting over the top of the vent pipe so that the air will be drawn in facing down or possibly sideways so rain or snow cant get in and leak more? I would be hesitant to do this over the toilet vent stack because i read here that sewer gases can enter the house. I am unclear as to the ramifications of doing this over the shower vent. I doubt a sleeve could be inserted b/c its too tight to access for that. I really dont want to break the walls or roof to replace the pipes if it could be avoided.
I would be very grateful to hear opinions, advice and experiences from all. Thank you so much in advance
Edited 1 times.
|
Post Reply
|
Author:
steve (CA)
If the water leaks out of the pipe in the attic area, then sewer gas can exit the pipe in the attic area. The pipe needs to repaired. If the attic is not accessible and opening the roof or ceiling is not desired, maybe the upper pipe sections can be lined from the roof down?
|
Post Reply
|
Author:
new2plum (NY)
Lining sounds like a great idea.. any advuce how to secure the lining??. Will sheet metal work? I dont smell sewer gases. Does the vent stack for shower meet up with toilet vent stack done the line? They both are totally vertical. Lastly what is the purpose of the shower vent stack. Thank u
Edited 1 times.
|
Post Reply
|
Author:
packy (MA)
one (not so common) problem with vent stacks in cold climates is 'frosting over'. the moist air condenses on the wall of the vent and freezes. eventually leading to a complete closing off of the vent pipe.
one way of curing this is to increase the size of the pipe just before it goes thru the roof.
this is how your stack is piped. to function as a vent the larger size is not needed.
so, you may be able to stick a piece of (2 inch ?) the same size smaller pipe down until it reaches the fitting that increases it in size.
use PVC, taper the bottom and put some silicone caulking on the bottom to get a seal. then you can deal with the pipe inside a pipe at the top of the stack. maybe one of the many fernco rubber 'donut' gaskets will help seal the top
|
Post Reply
|
Author:
new2plum (NY)
This sounds really good!! Im just hesitant to put pvc in the skinny pipe b/c it might create pressure and a smaller diameter to vent. Possibly a few inches of sheet metal at the link, then caulk. What do u guys think
|
Post Reply
|
Author:
bernabeu (SC)
TEMPORARY fix until vent is REPLACED
your idea of a 'return bend' above roof WILL WORK and was often done in NYC tenement buildings to prevent vandalism (broomsticks down vent)
in attic: use some of the 'seals everything' aerosols copiously on the cleaned and dried pipe to eliminate/minimize sewer gas
==============================================
"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638
|
Post Reply
|
Author:
new2plum (NY)
Will the return bend allow enough air into the vent.. why would i need to replace the whole pipe. I just cant justify that amount of work for a vent
|
Post Reply
|
Author:
packy (MA)
a return bend will work.. you do not insert a pipe smaller than the vent pipe. you insert a pvc pipe the SAME size as the vent before the vent increases in size just below the roofline.
|
Post Reply
|
Author:
new2plum (NY)
Thank u Packy. Last question.. will a 180 degree return bend work, or a 90 degree. If 180, does that need to be vented? Would a rain cap be a better choice?
Edited 1 times.
|
Post Reply
|
Author:
johnnybgood (NH)
Had same problem here , went to HD bought a vent cap for stove pipe, problem solved
|
Post Reply
|
Author:
packy (MA)
yeah, that will solve the problem of the rain getting in but not solve the problem of sewer gases getting out.
my solution may not be 100% perfect but it should get the person by...
|
Post Reply
|
Author:
new2plum (NY)
Thanks Packy,
Old post.
I ended up putting a "Master Flow adjustable versa cap" from Home Depot over the shower vent. This stoped the rain leak. As a reminder, I have 3 vents, all approximately 5 inches diameter at roofline, and this vent exclusively serves the shower, sink and tub NOT the toilet. This vent transitions into what looks like a 2" just before the bathroom ceiling. I have no attic.
I do still get a slowly running drain from soap and hair clogs that I now tackle by running hot water after every shower and give it a quick plunge every month and use a hair strainer. I don't remember if it drains slower now after I added the rain cap but I want to say probably not.
My questions are,
1.Would sewer gas leak through this vent even though its not serving the toilet? Do multiple standalone vent stacks intersect or not?
2. I don't smell any sewer gases, does this mean I have "nothing" to worry about? Is there a test for sewer gas levels.
3. in your or anyone's else expert opinion, do you think that the below posted link, adjustable vent cap, will allow adequate airflow into the vent? Other than a fairly slow drain, would there be any other symptoms of inadequate vent flow to a shower only pipe? Ive had this on for a few years now but am debating if I should consider a return bend instead. Am I overthinking this, or should I just leave the rain cap on and be happy? I believe another member put on a rain/stove cap and called it a day.
Also, your idea of a "pipe within a pipe" was brilliant, Im just not sure if the leak is below the 2" transition.
I think it may have been caused by rusting away and or snaking that went up the vent by mistake. I couldn't see anything obvious with the naked eye but when i poured a cup of water directly in the pipe, it immediately pouring out straight down on the first floor just below the exposed p trap (I ended up replacing the tub drain before the p trap) years back due to a leak from the previous owners probably using Drano on a Full clog.
Many thanks
[www.homedepot.com]
|
Post Reply
|
Please note:
- Inappropriate messages or blatant advertising will be deleted. We cannot be held responsible for bad or inadequate advice.
- Plbg.com has no control over external content that may be linked to from messages posted here. Please follow external links with caution.
- Plbg.com is strictly for the exchange of plumbing related advice and NOT to ask about pricing/costs, nor where to find a product (try Google), nor how to operate or promote a business, nor for ethics (law) and the like questions.
- Plbg.com is also not a place to ask radiant heating (try HeatingHelp.com), electrical or even general construction type questions. We are exclusively for plumbing questions.
Search for plumbing parts on our sponsor's site:
Special thanks to our sponsor:
|