One of the PVC vent pipes in my home’s wall vibrates inside the wall when it gets windy (I live on a mountian in Colorado and it DOES get windy!). This makes a tremendous racket with the sheetrock wall sounding like a drum beating.
I thought of just running some screws into it through the wall but then thought they might just vibrate loose and would also have the drywall repair hassle.
Then I thought of just cutting the pipe shorter on the roof. Then I thought – ask the experts first so here I am.
Thanks in advance – Rick
Replies
How about shooting some foam into the wall cavity, carefully?
Maybe you could try something simple (i.e., not involving opening up the wall or blindly screwing things) first, like changing the shape of the vent stack pipe (scallops?) or adding some sort of terminator (90* bend or a coupler section to take the top to the next size up?) to alter the aerodynamics of the top of the stack. Just a thought.
Mike Hennessy is on the right track. They make a vent cap that has the air come in or out below the top, that keeps the wind from creating a suction at the top of the vent. Plumbing supply houses should have them, give them the size of vent and the material its made of. [Size is I.D.]. Hope that this does some good. Lots of luck.
I'm not sure the wind blowing across the stack is the problem. When the wind gets going around35 - 40 mph gusts the whole pipe is shaking in the wall - it was put in the wall wrong so that its resting against the sheetrock in the instead of being suspended in between. But I'll call around and look for that cap to try, can't cost much.
If the whole pipe is shaking, that's not going to be good for the seal and flashing where it goes thru the roof. I'd try getting it well secured in the attic, near roof level, and again at the top of the wall. Look carefully, it might be leaking already.
-- J.S.
I thought that you had a bad installation, I was trying to come up with a simple fix. With a wind of up to 40 mph you have a major venturi effect on that pipe, the cap will negate most of those forces.. How high is the vent through the roof? [where I live the min. above the roof is 6 in.] if you are high you are getting side forces also. The spray foam that on of the other posts recomended I am iffy on that, without seeing what it is doing it has the potential to bulge your walls, [Your call], thats the best that I can do. You know what you have to do if none of the ideas on the forum work. May the force be with you.
Yeah I know - cut open the wall. The pipe is about a foot off roof level I guess. 40 mph is where it starts to shake but we get up to 100 mph gusts in January.
Its running through a cathedral ceiling so no attic to get at it unfortunately. THANKS TO ALL FOR YOUR ADVICE.
RTW
One other idea, has anything changed? Have you always had this problem? If not that gives you a clue of what to look for, something pertaining to the change. Lots of luck.