Vent Pipe
SO, this is weird, but I have this old vent pipe that runs up to the roof. I have no idea what it’s for. My issue is that there must be some sort of crack in the pipe somewhere, which is causing a small amount of water to run down my bedroom wall. I thought…
SO, this is weird, but I have this old vent pipe that runs up to the roof. I have no idea what it’s for. My issue is that there must be some sort of crack in the pipe somewhere, which is causing a small amount of water to run down my bedroom wall.
I thought about having someone weld some sort of “hat” on it to let it vent, but keep the water out, but from what I remember, it is recessed into the roof..
Anyone else have similar issue??
I have to admit that I am having a hard time digesting this technical stuff, but I do appreciate your info. It is definitely an iron pipe, no pitch pan, flat roof, 3 stories, leak seen on 2nd floor wall (don’t remember if water is coming from the 3rd floor run of the pipe because I had a different leak up there, albeit in the same corner). I’ve had this issue for years, so it isn’t from the bad weather we had this winter; and I’ve had my roof done twice, so I think there is something going on with the pipe. Pics coming soon!
And if anyone can tell me why my dishwasher makes a ridiculously loud noise until I grasp the hot water pipe under my kitchen sink, and why food/drinks on the top shelf in my fridge gets frozen all my prayers would be answered………
Got it. We need more info. My solution was premature.
Of course if the pipe is not moving much in relation to the roof, a seal to both is best. If it is moving, maybe just diverting the water away would help, not a complete seal. This is non-standard and meant for places where the problem keeps returning. I withdraw my suggestion to do it just as an extra precaution. I can see if it allows water to accumulate at the clamp and rust, it could even weaken a pipe. Strong wind, ice dams, etc. would not be stopped my an unsealed skirt.
Bpie weighed in, maybe it is a drain, or maybe it is a really old stack, which rusted through or cracked at the roof line.
Got it. We need more info. My solution was premature.
Of course if the pipe is not moving much in relation to the roof, a seal to both is best. If it is moving, maybe just diverting the water away would help, not a complete seal. This is non-standard and meant for places where the problem keeps returning. I withdraw my suggestion to do it just as an extra precaution. I can see if it allows water to accumulate at the clamp and rust, it could even weaken a pipe. Strong wind, ice dams, etc. would not be stopped my an unsealed skirt.
Bpie weighed in, maybe it is a drain, or maybe it is a really old stack, which rusted through or cracked at the roof line.
Because with the skirt, which is the preferred method on an all rubber membrane roof, it’s not going to stick to traditional roofing material surfaces. So unless the original poster has a rubber membrane roof already in place (which is pretty rare in Brooklyn on older roofs) he or she is just going to end up with the leak in another place, under the edge of the skirt.
And yes, ideally a pitch pan does attach to the roof sheathing, which is why I said that it’s a less than ideal solution, but in this case unless you want to start chopping holes into the roofing material, you would have to put it over the existing roofing material. Not the best scenario, but not the worst either and probably the best bet IMO to solve the problem.
The fact that there is a leak at the roof line doesn’t mean that the pipe expanded too much. The roofing cement may have dried out and cracked, there might have been too wide of a space between the roof and pipe and the mastic just oozed down into the hole, the roof could be saggin, there are just too many variables to say why the bond failed, but expansion or contraction of a cast iron pipe would be low on my list of suspects and a pitch pan will address most of the potential causes.
That being said, I didn’t spend enough time reading the post and glossed over the “recessed” part of it. As Steve and DIBS point out, we may be talking about a roof drain, in which case all bets are off. Pics please!
Bpie, you got a plastic or iron pipe? Did I miss something? I assumed iron. Bond, I admit a 3″ relative movement is a stretch, but Bpie’s leak may be due to much less. I wonder how much her roof sagged relative to the stack under the weight of last winter’s snow fall?
I do see roofing tar rubbed off of stacks at the roof line, and a similar problem to Bpie’s did occur, for instance at 245 Henry, Brooklyn, not a very tall building, but tall enough.
Bpie can google “Pitch Pan” and see that it attaches to the roof, not the pipe. Can you make like Onassis and wear your dark sunglasses and let us know if you even have a pitch pan? What floor do you live on, and How many floors does your building have anyway? Is it a flat roof?
Why not try belting a skirt on to a pipe instead or in addition? Why not try something new when many applications of glop, goop and goo either don’t work or stop working after they drip out in the heat of summer, or harden and crack in the cold of winter?
If it permanently sticks good, but not every bond is an agent.
Thanks to all of you for your comments. I need to go up on the roof and look at this again and take pictures. I mentioned it to my plumber (a family member, you know how that goes, he’s very good but I can’t be too demanding) and he didn’t seem too interested). It is a pipe that runs on the opposite wall of the chimney, in the corner at the back of the house. It may be a vent pipe for the ground floor crapper. I don’t know but the pipe is OLD. There is subtle water streaking on my bedroom wall (below the top floor). I had issues in that area on the top floor as well, but I think that was a leak in the roof. I’m thinking the water coming into my bedroom is from a crack in the pipe between floors.
This is not a pipe I would like to replace. I also need to go through the whole house to see the length of it and how invasive it is. I will look on the roof and take your suggestions. Thanks.
Well Green Mt.,. gotta disagree. Cast iron expands about 1/16 of an inch over a ten foot run as oppossed to 1/2 of an inch for PVC, which is why code requires expansion joints in long runs of PVC. While cast iron pipe and the building are both going to expand at different rates, they are both going to be expanding or contracting in the same direction, so on a 4 story house you’re talking maybe an 1/8 of an inch difference if that? You would have to be talking about one talllll building to see a three inch difference in expansion.
There’s a reason why large scale construction uses pitch pans.
This is one of the best questions I have ever seen on this forum. Answering it is as fun for me as finding an Indian-head penny in a wall cavity. Bond alluded to the problem, but tar and roofing cement are not nearly flexible enough. To the others: hats and caps won’t fix Bpie’s leak. What s/he needs is more like a visor or a tonsure, or a skirt.
I comment on similar problems I see in bathrooms and kitchens (my specialties), especially on upper floors of buildings with flat roofs. I have never seen or heard it even acknowledged by a plumber, roofer, super, coop board or building manager. Without seeing it, or at least pictures, I can not be sure in this case, but…
Stacks, start in the basement or cellar and expand and contract upward with changes in temperature. The rate of expansion of a cast iron stack is greater than the rate for the rest of the building. Where they are taller (more segments of pipe are stacked to reach upper stories) they expand more. You would not see the difference in expansion rates on a short building, but on the roof of a four story building, or greater, yup. On roofs of taller apartment buildings stacks and roofs slide up and down in relation to each other an inch or two or three or more.
I’ve seen the resulting gaps and cracks repeatedly filled with black glop, and where roofing cement is rubbed off of pipes, they are repeatedly coated with black gook, and the whole area is coated again with silver goo. Each peal of peeling paint from the rooms below, is answered by glop, gook and goo. Bpie’s recess is probably the contracting pipe pulling the whole mess downward. It became a funnel for rain water.
Rates of expansion of plastic pipe don’t matter, they are not allowed in tall buildings in NYC anyway. Vents for bath and kitchen fixtures move up and down when the stacks they are branched off of do too, but what I see is wet plaster and paint damage from irregular movement between roofs and stacks.
Bpie: the fix is easy and cheap. You need a flexible, sheet of roofing membrane about 1 x 2′ (uv resistant rubbery sheet) and a pipe or hose clamp big enough for your stack. Oh, and you need sunglasses. Wrap the membrane loosely around your pipe a few inches above the roof line so the bottom of the membrane rests on the roof and spreads out wider than the gap. Clamp it to the pipe at the top of the rubber. As long as your little, rubber, wrap-around skirt deflects most of the rain drops, snow and ice melt, away from the hole in your roof, it will work. What you will have is not a seal or a hat, but a “movement joint,” also called an “expansion joint.”
Movement joints are common in construction where materials expand and contract naturally. I don’t know why they are not installed routinely by roofers in situations like yours. I can only hope some landlords and coop board members reading this will insist their roofers install them where leaks are reported or at every stack regardless. The cost would be insignificant and the savings would be great. Best of all, building owners should keep people like Bpie from using their sunglasses to work on roofs. This is not safe, and it is not their job.
What master plumber said – it is not just sucks fresh air in. It also vents out water vapor and gases. If it leaks sewage gasses into the room you can get mild poisoning and headache.