" . . . exhausted directly to the outdoors?'

[Tom Cissell]

When the code says "exhaust air from bathrooms . . . must be exhausted directly to the outdoors" I am assuming this isn't quite directly enough. You guys agree?

[Rick Cantrell]

You are correct, must vent to outside,
That is not outside.
Can cause damage, mold, rot, smells.

[Tom Cissell]

You are correct, must vent to outside,
That is not outside.
Can cause damage, mold, rot, smells.


Thanks Rick.

[Larry Morrison]

I see this alot where I am even in brand new homes. Since I am in a desert climate with very mild winters, I will very seldom call it out and I have yet to see a problem with moisture in attics here (from venting). If I was a "code inspector", I would be calling it out however, our code inspectors around here are allowing it so calling this out on 90% of the homes is not the hill I want to die on...or build a reputation of being a pain in the rear.

In a colder or more humid climate...I'd be all over this! because the exhaust vents shown are terminating at probably the coldest (and most prone to condensation) than any place else in the attic (cold metal roof vent next to wood). That termination point is by far, worse than a vent terminating away from the roof deck in the middle of an open attic.

[Jerry Peck]

I see this alot where I am even in brand new homes. Since I am in a desert climate with very mild winters, I will very seldom call it out and I have yet to see a problem with moisture in attics here (from venting). If I was a "code inspector", I would be calling it out however, our code inspectors around here are allowing it so calling this out on 90% of the homes is not the hill I want to die on...or build a reputation of being a pain in the rear.

In a colder or more humid climate...I'd be all over this! because the exhaust vents shown are terminating at probably the coldest (and most prone to condensation) than any place else in the attic (cold metal roof vent next to wood). That termination point is by far, worse than a vent terminating away from the roof deck in the middle of an open attic.

You have stated that it is wrong ... yet then stated that you do not call it out ... I am stumped - if you know it is wrong then you decide for yourself as to 'how wrong it is' before you call it out?

ESPECIALLY with new homes where you said you see it "alot" - if you started calling it out on those homes you would eventually lead to the practice being discontinued and the bathroom exhausts being properly vented. Sure, it takes time, but it is worth it and it is about the only way you will make a difference to the practice has a reason to be abandoned by contractors.

(If I haven't shamed you enough into start calling it out ... let me know ... I tried. ;) )

[Mike Lamb]

I live in the Chicago area and if we are talking strictly bathroom exhaust termination, I have to say I have never seen a termination like this causing interior attic moisture problems. Unless there is something I don't see in this pic, I would never consider mentioning it.

[Lon Henderson]

I too, frequently see this done. Code inspectors around here rarely consider it worthy of correction. But, I write it up.

[Charles Wilson]

I see it frequently here down in Georgia. Yes I call it out. Yes I have seen moisture staining and mold as a result of it. As my mother would always tell me. Just because everyone else is jumping off the bridge doesn't make it right and doesn't mean you have to do it.

[Mike Lamb]

Yes I have seen moisture staining and mold as a result of it.

Do you have any pictures?


As my mother would always tell me. Just because everyone else is jumping off the bridge doesn't make it right and doesn't mean you have to do it.

No, it doesn't, but I'd advise you to find out why everyone is jumping off that bridge.

[Charles Wilson]

In the first photo Mike you can directly see the vent and the effect it is having. The second photo shows the exhaust line coming up and photo three shows the effect it is having. The first picture home was 12 years old. The home in the second set of pictures in less than 10 years old and the bathroom that vent was servicing was not the primary bathroom. Or so I was told.

[Mike Lamb]

Thanks, Charles. My comments were concerning the OP which looks like a roof louver vent job. Your pics look like somebody's real bad attempt at soffit venting which is a different animal and certainly worth writing up.

[John Kogel]

Here's some, how many do you need? :biggrin:

[Mike Lamb]

Here's some, how many do you need? :biggrin:

Hmm. 3 and 4 would seem to refute my experience; insulated ducts very close to or in a roof louver yet there is still mold/moisture problems. I want to say there is something more here than meets the eye. Those are not or were not blocked vents?

In your experience, you don't find this strange?

[Lon Henderson]

My unproven thesis is that we rarely see problems with this vent configuration in the Denver area, because of our very low average humidity. The only times that I've seen mold issues that might be ascribed to bath vents were in situations where the vents terminated far from any roof vents.

[Ted Menelly]

In the first photo Mike you can directly see the vent and the effect it is having. The second photo shows the exhaust line coming up and photo three shows the effect it is having. The first picture home was 12 years old. The home in the second set of pictures in less than 10 years old and the bathroom that vent was servicing was not the primary bathroom. Or so I was told.

Hate to contradict and you are more then likely right as you were there, but the first picture looks, to me, like a problem from above, not the bath vent blowing in to the soffit area.

[John Kogel]

Hmm. 3 and 4 would seem to refute my experience; insulated ducts very close to or in a roof louver yet there is still mold/moisture problems. I want to say there is something more here than meets the eye. Those are not or were not blocked vents?

In your experience, you don't find this strange?No, not so strange. It is never a surprise to see OSB go black in this climate. OSB absorbs moisture from the air and refuses to dry out. In pics 3 and 4, the roof vents were open, but the prevailing wind off the Juan de Fuca Strait may have been preventing the exhaust from getting out.

I see this same configuration in other houses with no sign of blowback, so results will vary, for sure. Roofers should put the roof vents on the lee side of the roof, but they tend to chose the side opposite the street for looks. I like the look of a row of vents myself. :D

Here's an example of cheap plastic duct tape letting loose. This attic had black streaks at the soffit baffles, but the big black smear with white spots were in this bay with the vent. I remember this place because the owner was meticulous and the house was near perfect from the ceiling down.

[Joe Funderburk]

The exact wording:

"M1507.2 Recirculation of air. Exhaust air from bathrooms
and toilet rooms shall not be recirculated within a residence
or to another dwelling unit and shall be exhausted directly to
the outdoors. Exhaust air from bathrooms and toilet rooms
shall not discharge into an attic, crawl space or other areas
inside the building."

[Rick Bunzel]

When the code says "exhaust air from bathrooms . . . must be exhausted directly to the outdoors" I am assuming this isn't quite directly enough. You guys agree?

When was the house built? Did the home meet the code at the time the home was built? If this is recent construction then it doesn't meet code. However based on the sheathing I suspect that this house is thirty years or more old. Most likely this venting was acceptable at that point in time.

//Rick

[Joe Funderburk]

When was the house built? Did the home meet the code at the time the home was built? If this is recent construction then it doesn't meet code. However based on the sheathing I suspect that this house is thirty years or more old. Most likely this venting was acceptable at that point in time.//Rick

100 years ago, many houses didn't have indoor plumbing. If I see that today in a 100 year old house, I'm writing it up. They don't have to take my recommendations.

[Tom Cissell]

When was the house built? Did the home meet the code at the time the home was built? If this is recent construction then it doesn't meet code. However based on the sheathing I suspect that this house is thirty years or more old. Most likely this venting was acceptable at that point in time.

//Rick


It is a condo built in 1968 but gutted in 2008. The exhaust vents were installed at that time.

[Jerry Peck]

When was the house built? Did the home meet the code at the time the home was built? If this is recent construction then it doesn't meet code. However based on the sheathing I suspect that this house is thirty years or more old. Most likely this venting was acceptable at that point in time.

I am not aware of any time in which the code allowed venting to anyplace other than the 'outdoors'.

The reason the wording is now ... so clearly stated ... is that AHJ could not wrap their head around the common sense wording of shall be 'vented to the outdoors' and said to the effect of 'well, the attic air *is* outdoor air, so, sure, vent to the attic' ... and because the intent of the code was *not* to allow that, the failure to get the various AHJ to understand 'vent to the outdoors', the code had to *specifically* state "shall not discharge into an attic, crawl space or other areas inside the building.", and even now some still say/ask 'does that mean it needs to be sealed to the discharge so it does not go into the attic?' ... Duh! Yeah, that is what it means. ... I guess the code may eventually need to state 'shall not discharge into an attic, crawl space or other areas inside the building AND SHALL BE SEALED TO THE DISCHARGE TO ENSURE that the air does not discharge into an attic, crawlspace or other areas inside the building.'

One would think that common sense would lead one to realize that is the intent, but some AHJ seem to be lacking that common sense.

[Michael Thomas]

People are endlessly creative...from this afternoon's report... total 12 bath vents into one attic:

[Billy Stephens]

People are endlessly creative...from this afternoon's report... total 12 bath vents into one attic:

Possible Drug Activity. :(

[Jerry Peck]

People are endlessly creative...from this afternoon's report... total 12 bath vents into one attic:

I doubt that white vinyl slinky tubing is an approved "air duct" anyway. There there is the supporting and securing part that they did not consider either.

The key part of the requirements is where the exhaust is not allowed to be recirculated and, as shown, there is nothing there which would prevent "recirculation" of the toilet room exhaust.

[Trent Tarter]

I find that quite often, some times routed near gable vents as well. I call it out every time, they should be connected proper vent caps so that all moisture is vented to exterior.

[Michael Thomas]

Possible Drug Activity. :(

Naw... just multiple condos below that attic.