Roof penetrations ...

[Bob White]

The photo below shows the roof penetration where four bath exhaust fan ducts terminate.

Download Attachment: venting.jpg

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This concerns me for a few reasons:

First, due to weather yesterday, I was unable to climb a ladder, get on the roof (it was WAY too steep anyway), or even get a view of this penetration from the outside of the house even from a distance with binocs.

Second, I have never seen this before. Upon close examination, you can see that this Wye fitting is either screwed or neiled or boltd to the underside of the roof sheathing. Then it is covered (sealed?) by the same type of mastic that the HVAC guys use to seal their ductwork at the evap.

So, if the flashing up topside goes bad, it may be a very long time before anyone in the house notices the leak, resulting in some roof decking and shingle replacement along with the simple flashing boot replacement.

My Questions: What is the proper name of that wye apparatus?

Is this installation as wrong as I think it is?

Bob

[hausdok]

Hi,

It's a vent wye. That's about all you need to call it. It's getting 100% of the air to the outside, that's all you need to be concerned with. Look at the underside, look at the topside. If it looks like it's flashed normally and that's all you can see, you've done all you can do.

You aren't expected to have X-ray vision or be a swammi and capable of predicting the future.

ONE TEAM - ONE FIGHT!!!

Mike

[Jim Katen]

Originally posted by Bob White

. . . First, due to weather yesterday, I was unable to climb a ladder, get on the roof (it was WAY too steep anyway), or even get a view of this penetration from the outside of the house even from a distance with binocs.

Just for fun, I'll mention that I once got a neighbor to allow me to view a roof from her upstairs bedroom window. She was very nice about it.

Second, I have never seen this before. Upon close examination, you can see that this Wye fitting is either screwed or neiled or boltd to the underside of the roof sheathing. Then it is covered (sealed?) by the same type of mastic that the HVAC guys use to seal their ductwork at the evap.

So, if the flashing up topside goes bad, it may be a very long time before anyone in the house notices the leak, resulting in some roof decking and shingle replacement along with the simple flashing boot replacement.

Nah. If the flashing leaks, that duct mastic won't do squat.

My Questions: What is the proper name of that wye apparatus?

It's just called a wye.

Is this installation as wrong as I think it is?

Bob

I don't believe it is. The worst thing I can think of is that, if the vent becomes clogged after the wye, the exhaust from one bathroom will blow back into the other bathroom. (Well, as much of it as can get by the fan's integral damper.) That doesn't seem like much of a problem to me.

- Jim in Oregon

[Bob White]

OK,

Thanks much for the information guys ...

[DonTx]

We've been seeing this for about the last 18 months down here. I much prefer this over running them over to a soffit.

The only ones I've seen fail are where the roof jack is not installed properly. But beware, many builders seem to think you can do the dryer vent that way also (running them into roof jacks). Dryer vents are required by the IRC to have backdraft dampers.

Good Luck,