Plumbing and Piping - Vent Pipe Leak! Help!

Hi,

Over the last few weeks, we have had periods of heavy winds (the house was creaking) and wild temperature fluctuations (30 one day, and 60 the next). I'm not sure if this is what caused this, but my plumbing vent pipe starting leaking at an elbow in the attic. There was nothing leaking from the flashing. It's PVC piping, dry fit, no sealant. Anyway, I sealed up that elbow, and now I noticed yesterday (after heavy rain) that it's leaking again from a pipe running in between the 1st and 2nd floor. There's about 5 drip stains about a foot apart about the size of a baseball running in a straight line across my kitchen ceiling. I don't want to have to cut drywall only for this to happen somewhere else.

My vent pipe is uncovered, should I just cover (not cap) the vent to keep the rain water out?

Thanks for everyone's help!

It's PVC piping, dry fit, no sealant. Anyway, I sealed up that elbow...

Can you elaborate on what you mean by "dry fit"?

The PVC pipe sections and fittings should have been cleaned and then glued together, one installed they should not require any additional sealant.

Hi,

Thanks for the reply. By "dryfitting", I mean that the elbow joint wasn't glued, screwed in, or sealed. It was simply slid up as tight as they could get it. Unfortunately, other than the main joint (not sure of the technical name) just below where the vent pipe exits the roof, none of the elbow joints are glued; they're simply dryfitted.

Hi,

Thanks for the reply. By "dryfitting", I mean that the elbow joint wasn't glued, screwed in, or sealed. It was simply slid up as tight as they could get it. Unfortunately, other than the main joint (not sure of the technical name) just below where the vent pipe exits the roof, none of the elbow joints are glued; they're simply dryfitted.

That's COMPLETELY wrong, and whoever "they" are, "they" need to come out an fix it, or pay for someone else to do it - and I shudder to think what else might have been done wrong... did the same people do any wiring?

Well...the townhome is 10 years old, and the work was originally done by the builder. I guess I should be happy it lasted this long. The builder did the electrical work too, but I'd imagine it was done by a different subcontractor. Anyway, I thought that was strange when I went up there in the attic and was able to slide it out without much effort. I figured it wasn't pressurized, so that's why they didn't glue it or seal it.

So now I'm thinking the whole vent system may be compromised (obviously, with 2 separate leaks!). It only took 10 years of sagging to do the trick. So, I guess the only inexpensive solution is to cover the vent (not cap it) so no rain water gets it. What do you think?

What I would tell my home inspection clients in this case is:

"Sounds like somebody dry fitted the top portion of the vent stack and then forgot to go to glue it together, and then the AHJ took the plumber's word that it had been pressure tested instead of observing the actual test.

The question is now: how far down is that stack only pressure fitted together?

If all the portions of the stack that are "wet" were properly glued together than the worst that can happen is the vent stack sections above disconnect, and you have sewer gas entering the building from inside the attic or perhaps inside a wall. That can be highly annoying, it's potentially a health hazard, and also potentially a fire and explosion risk.

If any portion of the stack that's "wet" (that is, below the highest level at which plumbing fixtures drain into it) was not glued, and works itself loose; then you're going to have water, and potentially water contaminated with human waste, flowing into the structure from the leak in the pipe.

What you need to do is to start by properly joining (or have a plumber join) all the accessible portions of the stack, including opening ceilings and walls to reach any portions which are currently leaking.

Once you've done that, have a plumber pressure test the DWV plumbing (harder to do once fixtures of the installed, but necessary) to ensure that everything else is properly glued together.

If it's not, then you will have to open up the structure as required to locate and repair "dry fitted" connections.

That's potentially a lot of work, but the only the way you can be certain that you're not going to wake up smelling sewer gas and/or having water contaminated by human waste leaking into the house."

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If they asked me if they had to do all that, I would tell them that I'm legally obligated to recommend whatever steps are required to achieve a safe environment within the house and that while they could certainly fix the apparent problems and "wait to see what happens", or kludge up some sort of device to keep rainwater from entering the stack from the exterior, that's a course of action I'm not legally allowed to recommend. I would also point out that was my house I would prefer to know that it was fixed right rather than run the risk of unpleasant surprises later.

YMMV.

Wow...I never considered any of that!

Thanks so much for your help!

In 25 years of plumbing, I have never read a story like this one. I have seen some pretty weird things in the plumbing field, but never a whole vent system not glued. Obviously, the inspector was on the take or something.