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vanishingson 04-02-2011 01:05 AM

Wrong roof vent for bathroom exhaust?
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Hello all,

This is my first post in the Forum so I'm hoping someone can give me some insight. Please excuse me if it is a bit long.

I recently noticed a growing rusty water stain and bubbling drywall on my main floor wall. It is in the corner where the 2 walls meet the ceiling. I have also noticed water dripping from the door frame just below the water stain.

Even though there is a bathroom directly above on the second floor, through a series of observations and measurements I've ruled out any interior plumbing leaks. The stain grows, the water drips, and the drywall gets moist, ONLY after heavy rain.

I will be cutting open a piece of the drywall to have a look inside. I have 2 suspicions as to where the water is entering. Both of which are vent related:

1. I have a clothes dryer on the main floor that vents out to the side of the house directly above where the water stain and drips are occurring. (The vent looks similar to the first pic I attached.) I have tried to seal around the vent but that didn't seem to help. I do have a small crack/hole on one of the vent flaps. Is this enough to cause noticable water stains and dripping in a short period of time?

2. I had a bathroom exhaust fan installed a year ago on the second floor bathroom (as mentioned before it is directly above the area of the stain). The contractor that installed it, vented the fan out through the roof. Instead of installing a typical exhaust vent cap on the roof exterior (which should look more like a box or a hood) he used what looks like a sewer pipe vent. (Similar to the second pic I attached). I don't think there is anything covering the pipe opening. Shouldn't this at least have a rain/vermin cap of some sort? Is the water that gets in there during a rain enough to cause the staining and dripping?

I suspect that it is one of these or a combination of both that is causing my problems. Since I'm not made of money and can't hire someone to go on a hunting expedition, I'm trying my best to eliminate these as probable causes one by one. So I can figure out exactly what needs to be fixed, attempt to fix it or hire a professional if its beyond my capabilities.

If I was unclear or not detailed enough, please ask me questions. Any insights you may have is greatly appreciated.

OldNBroken 04-02-2011 09:12 AM

If that is your exhaust pipe that is okay but it is not complete. Easiest fix for it is a gooseneck on top so it's pointing downward (two 90degree elbows) with a 1/4" or 3/8" mesh screen capping the gooseneck. However the exhaust you have needs to have a bathroom exhaust fan adequate enough to push the air that far properly. Most standard bath fans are designed to adequately push air horizontally for a short distance. You are going two stories vertically and your fan may be too weak to vent properly with your setup.
Even then, I don't see how that would cause a leak like you describe. It sounds like, if it is this vent leaking , it is improperly flashed to the roof. Could not tell you how it is improper without seeing a closeup picture of it though.

tinner666 04-02-2011 03:43 PM

I had a leak like that a year or so ago. In that case, the wall vent wasn't flashed or caulked along it's top side, nor 3" down each side.
Water was getting in and following the duct work and leaking about 14' inside the house.

As for the vent on the roof, it looks OK from where you took the pic from, but the rubber may have split. You need to get up close and presonal to see if that's the case.

vanishingson 04-02-2011 04:21 PM

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Thanks ONB and tinner. The bathroom is on the Second floor and the connection does run horizontally about 3 ft. to meet the pipe. I've attached an actual pic of the exhaust. (The first one was just for reference) It's as close as I can get for now. I did go in the attic to see if there are any water damage or stains inside. I did not find any.

I also attached a the pic of water stain/damage I was referring to on the Mainfloor. And directly outside that is the wall vent. (pic also attached) You can see where I've tried to caulk around the top and right of wall vent, as well as the crack/hole in one of the flaps.

If the water is not coming from the roof and travelling down to show up on the main floor, this wall vent is next on my list of possible causes. There are no signs of water leaking on the second floor at all. What do you guys think? Am I targeting the right things? Or are there other places I should be looking? Tinner666, how did you trace the leak source from 14' inside the house to the wall vent?

I'm cutting a whole in the drywall today where the larger damage is and see what's in the walls. But without any rain forecasted for the next 2 days. I don't now if I will see anything at this point.

kwikfishron 04-02-2011 04:28 PM

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Can you post a picture standing back showing the outside wall of siding from the top of the door to the roofline?

vanishingson 04-02-2011 06:48 PM

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here you go kwikfishron...

Notice that the pipe vent in question on the roof is a couple of feet to the left of the wall vent. If the source was the pipe vent, water would have to travel the lateral distance as well.

Where as the wall vent is directly on the other side and just above of the interior water stain/damage.

I know the obvious may not always be the cause... :(

kwikfishron 04-02-2011 07:34 PM

199 Attachment(s)
Thanks for the pictures.

Here’s a little more homework for you.

How about a couple of shots showing the flashing detail around the chimney, about as close as your second picture of the roof vent.

I’ll put money on the roof vent your suspecting isn’t the culprit.

OldNBroken 04-02-2011 10:43 PM

I agree.

First, that is your plumbing vent, not bath exhaust coming through the roof so basically ignore everything I posted about that. Second, never knew about the chimney until you posted that pic. I'm putting my money on the chimney leaking. Is the leak anywhere near it?

Gary in WA 04-02-2011 10:51 PM

Before you cut the drywall, check to see the flappers on the dryer vent termination open fully. The duct pipe could have dis-connected in the attic, check there second. If that is the dryer vent (I don't see any sign of lint on the siding).


vanishingson 04-03-2011 09:36 AM

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ONB... it is the bathroom exhaust. My contractor just used the wrong vent termination. I went in the attick and confirmed it. the bath exhaust does infact connect to this pipe. My sewer exhaust pipe is in a different location (behind the chimney actually).

Having said that, I think I can now confirm that this pipe is NOT the source of the leak. Should I bother putting a rain cap on it anyway?

KWIKFISHRON...The big news of the day is... I did my homework as you asked. Bright and early this morning I went up on a ladder armed with my camera. Pics attached of what I found. All of this was behind the chimney and was hidden from view. Not until I went up for a closer look did I notice some debris. I reached as far around as I could with the camera and couldn't get right to the back of it. But safe to say... this shouldn't be like this! And yes ONB the leak is definitely in the exact vicinity of the chimney!

So can I declare "mystery solved"?!? What could have caused this? It looks like an animal has torn it apart. I checked the attic again to make sure I didn't have uninvited guests and there was none. Is it just normal wear and tear or weathering? Was there something I could've done to have prevented this from happening?

kwikfishron 04-03-2011 10:34 AM

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Be careful, your roof went from easy to walk from your first picís to donít try this at home by the last.

Looks like Raccoon damage to me, could be wrong though. Iíve seen them get under the eves of dormers thrashing the roofing up in the process.

Hire a reputable roofer to fix that mess, not just some guy willing to get on your roof.

Although the exposed plywood is defiantly a leak I see other things that could be problems too. Everything, window, siding, etc. all terminating into the brick is never an ideal situation since your relying on just caulking to keep the water out.

Get the roof fixed but if you still have any problems Iíd get the hose out and slowly work from the bottom up spraying where the house meets the brick, youíll find the leak.

The best way to keep those kind of critters off the roof is to give them no access. Might be time for some tree pruning.

OldNBroken 04-03-2011 10:39 AM

Congrats, you win! Well, sort of... Anyways, . Did anyone remove any snow or a big chunk of ice behind the chimney recently? Don't know your location but it looks like the roofing could have got imbedded in ice and it broke free or was broken free by someone. Either way now you have something else to fix. Never seems to end does it.

vanishingson 04-03-2011 12:11 PM

Yes it is now a significantly more involved repair. And yes I will be going to a professional at this point. But I am extremely happy that with your help, I managed to find the source and now I have a more definite plan of attack. As opposed to going on a blind expedition. Knowing is half the battle! :)

And yes, I will keep a close eye on this from now on.

I can't thank you guys enough for all your advise and help. This is my first home and the more I know about the way things work, the better equipped I am to deal with the joys of home ownership. Once again, my hat's off to you!

Ron6519 04-03-2011 03:56 PM

While you're up there, you can repoint the chimney.

rossfingal 04-03-2011 04:33 PM

Yes "tuck-point" the chimney -
get a pro to do it - check the "chimney cap".

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