Bathroom vent piping to "Near Exterior"?

[Steven C. Waskewicz]

Because of the dry climate where we are, I usually don't make an issue out of this type of plumbing vent run for bathroom fans.
I thought I'd post this recent inspection shot that I did, to see what others think about this?

I believe the perfect solution should be a vent, directly to the exterior.

(And in the imperfect world we live in, it sure looks like this would solve any possible moisture problems,
at least here in low-humidity-colorado.)

Opinions welcome.

[Billy Boerner]

Originally Posted by swaskewicz

Because of the dry climate where we are, I usually don't make an issue out of this type of plumbing vent run for bathroom fans.
I thought I'd post this recent inspection shot that I did, to see what others think about this?

I believe the perfect solution should be a vent, directly to the exterior.

(And in the imperfect world we live in, it sure looks like this would solve any possible moisture problems,
at least here in low-humidity-colorado.)

Opinions welcome.

I agree vent directly outside however since it's legal simply venting them to the gable vent without having to cut holes in the roof is the preferred method to save money for builders.

[Bob Elliott]

I would be more concerned if it was a dryer vent ,but in a cold climate such as yours , is there not a possibility of freezing up the opening and cutting off attic ventilation.

[mnahrgang]

For new construction around here, the AHJ's (St. Charles) want the vents 18 inches above the insulation. To a gable, to a soffit, or to the exterior is ok too. We've got pretty humid summers, and I've not seen much issues with this. The only issues I've found is rusted nails from winter condensation/thawing/dripping and that was an older home. Relatively speaking, you almost never see bathrooms vented to the exterior here.

[Dave Bush]

Mark, same thing here, as long as it is 18" above the insulation, it is considered sufficient here.

[Marcel R. Cyr]

Originally Posted by swaskewicz

Because of the dry climate where we are, I usually don't make an issue out of this type of plumbing vent run for bathroom fans.
I thought I'd post this recent inspection shot that I did, to see what others think about this?

I believe the perfect solution should be a vent, directly to the exterior.

(And in the imperfect world we live in, it sure looks like this would solve any possible moisture problems,
at least here in low-humidity-colorado.)

Opinions welcome.

Steven, is that two bathroom vents and one dryer vent in the smooth duct.?

Makes to much sense to just vent up through the roof with a $5 vent cap?

Hate to see what happens with a prevailing wind, and no ridge vent.

Why is the felt paper directly on the truss framing.?

I know, I know, I ask to many questions right.?

[Bob Elliott]

So you guys in Missouri have no problem with intentionally soaking the underside of roof sheathing that creates mold. ?

We are talking warm ,humid air.
OK.

In that case i guess blocking the Gable vent is fine and dandy.

[mnahrgang]

Originally Posted by belliott

So you guys in Missouri have no problem with intentionally soaking the underside of roof sheathing that creates mold. ?

We are talking warm ,humid air.
OK.

In that case i guess blocking the Gable vent is fine and dandy.

That's just it... The humid bathrooms venting to the attic apparently cause no harm. My own home for example has the vent directly into the insulation. There is no ducting at all. Zero, and I say again, zero moisture problem in the attic. Apparently the natural ventilation of the attics around here is sufficient. I've only found one older home that had any problems at all, and that was the rusty nails and winter condensation.

[Bob Elliott]

Mark you do know that simply because for some reason you never had a problem that it is still a issue?

[Buck Hartley, CMI]

In the Kansas City Metro it is not a requirement. But I always write it.

[Steven C. Waskewicz]

Thanks guys, you all are thinking the same as I am.

I did in fact, mention it in my report, but not in an alarming way, but more
of an informational statement.

[Steven C. Waskewicz]

"Steven, is that two bathroom vents and one dryer vent in the smooth duct.?"
Hi Marcel, I believe its two bathroom vents and one dryer vent.

Makes to much sense to just vent up through the roof with a $5 vent cap?
I hear you, I guess the builders are content with just up into the attic...

"Hate to see what happens with a prevailing wind, and no ridge vent. "
We have some incredibly high winds out here on the front range,
I've personally seen gusts as high as 90 - 100 mph, and anything thats not nailed down is blown south...
Very few homes actually have full ridge vents, more than likely (like this home) the soffit vents and gable vents suffice for breathing the attic.

"Why is the felt paper directly on the truss framing.?"
That is actually the back side of the fiberous type sheathing applied as the skin to this building.

"I know, I know, I ask to many questions right.?"
No problem, glad to chat...

[Marcel R. Cyr]

Steven, thanks for the reply, and what I meant by prevailing winds, and you just enforsed it with the wind speed you get, won't this wind just blow in the exhaust ducts and force it in a reverse motion in the house when they are being used?
Just curious.

[Joe Funderburk, CMI]

You have to keep in mind that most bathroom vents are simply fart fans.

[Joe Funderburk, CMI]

Originally Posted by mcyr

Steven, thanks for the reply, and what I meant by prevailing winds, and you just enforsed it with the wind speed you get, won't this wind just blow in the exhaust ducts and force it in a reverse motion in the house when they are being used?
Just curious.

Most exhaust fans have a back-draft damper.