Vent pipe leaking

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New Member
Sep 20, 2021
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Hi folks, I'm new to this forum and appreciate any feedback you may have.

I purchased a house in North Port, FL last December and I recently noticed, what I deem to be, a vent pipe leak. The house was built in 2016, so is relatively new.

I have a crawl space on the second floor of our 4 bedroom house that sits directly above the master bedroom, downstairs. In this crawlspace sits HVAC ductwork and some other things as well as (what I assume to be) a plumbing vent pipe for the upstairs and downstairs bathroom. The 2" PVC pipe runs from the floor into the crawlspace a few feet and makes a 90-degree turn and heads to the roof.

During heavy rains, which are common in this neck of the woods, that pipe "leaks." The last time we had such a deluge, water was dripping from this pipe in the crawlspace and consequently though my ceiling into the master bedroom. It wasn't big enough to create any real damage but I will need to replace/repair part of the ceiling. I jumped into the crawlspace and there was no visible water leaking from the top of the pipe (as it makes its way outside) and the area around the top of the pipe where it connects to the roof sheathing was dry. Checked the 90-degree elbow and the bottom of this elbow was wet. I did also check the outside and there don't seem to be any obvious water intrusion spots on the roof ( I could be wrong.)
So, like most DIY'ers I took my happy butt to Home Depot purchased a new elbow, cut, and reglued everything back. Truth be told the PVC cement I had was gummy so I wasn't sure whether or not it would hold but I did use the primer and quite a bit of the cement and it seemed to hold.

Fast Fwd another few weeks and after another downpour the master bedrooms ceiling is wet again in the same exact spot as before.

A couple of scenarios that come to mind:
1. The roof vent has a flap that lets air out, not in, so unlikely that much water is making its way into the vent to create a leak.
2. I could get some tar and recaulk the outside of the vent and possibly plug up any potential leak coming from the top of the roof? The first time I checked, however, there wasn't any visible moisture on the vertical pipe coming from the roof and the roof sheathing was dry.
3. The vent could be clogged and backing up to that elbow and leaking from where that gummy cement didn't seal properly.
4. The gummy cement didn't seal properly and during serious downpours, water makes its way inside the pipe and hits that poorly glued elbow and leaks.
5. The Vent Pipe is clogged and the water sits in the pipe and leaks at the elbow?
5. or??

So, I'm not about to call a plumber who will charge me an arm and a leg for something I can potentially fix myself so, any thoughts from our resident plumbing experts would be greatly appreciated




Feb 9, 2021
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United states
Inspect while it’s raining.

Put a water hose in the pipe on the roof and then inspect for leaks


Well-Known Member
Aug 9, 2020
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Is it possible that condensate is occuring inside the pipe? The dampers that don't let air back in are not perfect seals.

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