This is probably a strange question but I am having a difficult time finding the correct information.

I am wanting to install a ventallation fan in one of our bathrooms that does not currently have one in it. The other bathrooms in my house have the fans but they are not vented out through the roof. Currently they are just venting directly into the attic.

From what I have read, the bathroom fan must be vented through the attic and out the roof area to prevent mold and moisture building up in the attic.

I don't particularly like the idea of cutting a hole in the roof to put in a vent because the roof is really steep on my house and the other bathroom vents are vented directly into the attic,, but I don't want to install the fan improperly and have problems later as this new fan will be in a room that has a shower/tub directly in it.

Does anyone have any experience or ideas with this issue?

The code requirement to exhaust to the outside is relatively new. Within the last 10 years give or take. Before that we just it just went to the attic. If you don't want to go through the roof I've seen them run into a soffit and go through the plywood with a dryer type vent.

Ya that is a fairly new code. You can vent it through the roof and they make some kits for that (http://www.homedepot.com/p/Broan-Roof-Vent-Kit-RVK1A/100344509). I believe you are not supposed to vent through the soffit.

It isn't a particularly hard job to do but I think a handyman could get it done for a couple hundred bucks.

This video is what people pointed me towards: https://www.youtube.com/watch?v=PqrZWd_CQIE

You definitely don't want to vent into the attic. Venting through the Soffit is not recommended because that's where air comes into the attic so that humid air may end back up in the attic.

I have a newer house, less than 10 years, and mine are vented into the attic. Attic itself is vented in multiple locations, soffit, roof, so I don't see why it would need anymore than that.

I have a newer house, less than 10 years, and mine are vented into the attic. Attic itself is vented in multiple locations, soffit, roof, so I don't see why it would need anymore than that.

My house was built in 1998. I guess that explains why none of the other existing fans were vented through the roof.

The attic area is vented through the soffit and out the roof. The attic area is very large due to the steep roof.

I guess my concern is that since the new fan will be going inside a room that has a shower in it, there would be more of a change of moisture getting sucked into the attic and causing issues.

I have also read that you're not supposed to run the vent to the soffit since the hot humid air could be sucked back into the attic area.

My house was built in 1998. I guess that explains why none of the other existing fans were vented through the roof.

The attic area is vented through the soffit and out the roof. The attic area is very large due to the steep roof.

I guess my concern is that since the new fan will be going inside a room that has a shower in it, there would be more of a change of moisture getting sucked into the attic and causing issues.

I have also read that you're not supposed to run the vent to the soffit since the hot humid air could be sucked back into the attic area.

I guess I'm more concerned that since my house is so new, why they weren't vented that way if it's code. My attic too is very large due to steep roof and mine are in both bathrooms. Honestly I don't use them most of the time, so I suppose it's kind of a non issue for me. I'm always interested to find out what new codes there are. Seems like that stuff always changes.

This is purely anecdotal, but......

Our house was built in the 60's and the bathrooms and even the clothes dryer vented into the attic.

We bought the house in 2012. So, for about 47 years the previous occupants vented into the attic that whole time. Guess what? Zero mold or other damage in the attic. Now, it's a BIG attic with lots of venting built into it, so that probably had a lot to do with it.

We initially tried to vent through the roof (extended the pipe that previously ended in the attic). However, our dryer kept throwing a warning light telling us the 'vent is obstructed.' We were told the dryer (brand new and expensive) could not effectively push the air from the first floor, past the second floor and out the roof - too long of a path and too narrow of a pipe. So, we vented straight through the exterior wall to the outside. I'm guessing it wasn't originally built this way because the washer and dryer are not on the exterior walls (we ran the vent along the wall to the exterior wall and then cased it all in).

As for the bathrooms; 3 vent straight into the attic. The 4th has a bedroom directly above so it uses a nice ventless bath fan. The ventless seems to work well at keeping the room from fogging up.

Is ventless an option for you? (FYI - there are all kinds and some work well and others seem to do nothing at all)

Zuplar, probably because it may not have been code 10 years ago. Here's a rundown on the issue and it looks like having just an operable window or a vent fan to *somewhere* was okay until 2009.

http://thehtrc.com/2013/getting-details-right-bathroom-exhaust-venting

None of this may have applied, of course, there were various codes around published by different entities that municipalities used or didn't use as they saw fit. Some cities, OKC included, would lag behind in adopting the current code(s), because it takes awhile for the new code to be reviewed and passed into law at the local level. That changed somewhat with the formation of the Uniform Building Code Commission in 2009 who now sets the minimum code standards for the state. https://www.ok.gov/oubcc/

The cities can still add on more stringent requirements, and they sometimes do. So if you want to know what actually applies you have to look at the minimum the state requires and then see if the city you live in requires something more stringent. Simple, huh?

I figured as much, although my house is still in that range. Like BBates alluded too, it's probably not something to overly concern yourself with if your attic is well ventilated, which mine is.

I figured as much, although my house is still in that range. Like BBates alluded too, it's probably not something to overly concern yourself with if your attic is well ventilated, which mine is.

My house was built in the 50s, has two fans vented into the attic and no mold issues in the attic. The attic is vented fairly well though. I have one bathroom that really needs better air circulation. Mold tries to grow on the shower tile and it's always humid. The other bathroom has a supply vent near the tub and does much better. I was just thinking about changing out that fan to a larger one after scrubbing all the grout this weekend. Both had new tile in the last remodel a few years ago.

My house was built in the 50s, has two fans vented into the attic and no mold issues in the attic. The attic is vented fairly well though. I have one bathroom that really needs better air circulation. Mold tries to grow on the shower tile and it's always humid. The other bathroom has a supply vent near the tub and does much better. I was just thinking about changing out that fan to a larger one after scrubbing all the grout this weekend. Both had new tile in the last remodel a few years ago.

After you clean that grout nice and good, let it dry and put some sealer on it if you haven't. If you have and it's been awhile you can still put another coat on. This won't eliminate the need for the fan, but helps with the mold issues.

After you clean that grout nice and good, let it dry and put some sealer on it if you haven't. If you have and it's been awhile you can still put another coat on. This won't eliminate the need for the fan, but helps with the mold issues.

I was thinking about doing that again. I sealed it when it was new.

According to these guys, it's OK to run it out a soffit:

https://www.nachi.org/forum/f16/soffit-bath-fan-ventilation-49741/

When bathroom vents were first ducted to somewhere they would run dryer duct from the fan and just drop in in a soffit. This was how it was done for a short time when bathroom exhaust first had to be ducted. That's not good and that's what they mean by not running the vent to a soffit. Running it out the bottom of the soffit into outside airflow is fine.

Do you think that mold growth/moisture issue in an attic isn't such a big deal here in Oklahoma since most of the time the humidity levels in Oklahoma tend to be on the low side?

I could see it being a bigger issue in more humid/tropical states.

I installed the fan tonight but have not vented it outside yet. Double checked again that the other fans in all of the other barrooms are venting directly into the attic.

Also, wouldn't a home inspector catch this and possibly flag it or at least bring it up on the inspection report before we purchased the house?

Do you think that mold growth/moisture issue in an attic isn't such a big deal here in Oklahoma since most of the time the humidity levels in Oklahoma tend to be on the low side?

I could see it being a bigger issue in more humid/tropical states.

I installed the fan tonight but have not vented it outside yet. Double checked again that the other fans in all of the other barrooms are venting directly into the attic.

Also, wouldn't a home inspector catch this and possibly flag it or at least bring it up on the inspection report before we purchased the house?


Can't speak much to the point of humidity -- we certainly get quite moist in the summer, but nothing like in the southeast where moisture condenses on windows all day every day in the summer.

As to the inspection -- It depends. Some are better than others.. not all of them are trained to the same standards. Sadly, some only exist to help speed along the process of a home sale, while others do it as a science and will scrutinize something as simple as the location of a supply vent in a room.

I'm not sure about this. Really just saying how I think home inspectors are expected to work. If a piece of equipment is in good working order and is up to the code for the time the home was built I'm not sure there's anything to report.
For instance. If an inspector wrote that a house built in say 1990 had to be brought up to current code there would be some major changes. Arc fault breakers, breakfast room outlets on a GFI circuit, foundation steel bonded to the grounding system, outside lighting wired with underground listed wire, etc., etc. Would get pretty expensive.

Our current home is 30 years old. 2 full baths with fans venting into the attic. Low roof profile, You can only stand up straight at the peak. Good attic ventilation and no moisture or mold issues. If adding a fan my self, I wouldn't have a problem of installing another one that vents into the attic. It's not like it would be running for hours at a time pumping large quantities of moisture up there.

As for dryer vents exiting out of the roof, our last house had a nice convenient laundry room in the middle of the house. But the dryer vent hood on the roof would catch lint blow by in the bird screen, causing poor exhaust flow and the dryer to over heat. On 2 different occasions, I had to get up on the roof and pull the cover apart to clean lint out of it. So for that reason, I'll don't like roof top dryer vents.

Can't speak much to the point of humidity -- we certainly get quite moist in the summer, but nothing like in the southeast where moisture condenses on windows all day every day in the summer.

As to the inspection -- It depends. Some are better than others.. not all of them are trained to the same standards. Sadly, some only exist to help speed along the process of a home sale, while others do it as a science and will scrutinize something as simple as the location of a supply vent in a room.

Bought our house built in 1950 in August last year, had "A to Z" do our home inspection - the 2 inspectors took 3 hours to do the inspection (looked at *everything*) and came back with an incredible list of things that they found, categorized by "bad - really really should fix, not too bad - should fix, OK - doesn't need fixing, but might in the future, OK - for the foreseeable future", basically. One (or both, can't remember, will have to look through the 30 page report) of our bathroom fans was vented to the attic and was marked as "should fix", he said basically the same thing - vents to the attic, should really vent through the roof - but didn't say it *needed* to be fixed.