# Bathroom Exhaust Fan Venting into Attic



## koz123 (Jan 17, 2011)

Hello everybody, I'm new to the site so hopefully this is posted in the correct spot.

I had small water marks (mold?) on my bathroom ceiling that were very small and probably not caused by a leak. I also had an issue with a wall mounted artwork (paint chipping) in the same bathroom so I figured I wasn't getting proper ventilation from the exhaust fan. I went up in the attic and didn't find any leaks but the vents are only about 3 feet long and aren't leaving the house, instead just moving air directly into the attic. I'm guessing this isn't adequate?

If not, what's the best path forward?

Thanks in advance for any replies.


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## gregzoll (Dec 25, 2006)

Confused. Are you asking about the attic vents, or how the exhaust fan is vented out of the bathroom. It should not vent into the attic space, it should exit through a sidewall, or the soffit in the attic.


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## koz123 (Jan 17, 2011)

gregzoll said:


> Confused. Are you asking about the attic vents, or how the exhaust fan is vented out of the bathroom. It should not vent into the attic space, it should exit through a sidewall, or the soffit in the attic.


About how the exhaust fan is vented out of the bathroom. It's currently just vented into the attic. There appears to be roof vents in the attic, but the bathroom exhaust fan isn't piped directly to any of them. Does that make sense? I'm not sure if I'm explaining it properly.


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## gregzoll (Dec 25, 2006)

It needs to vent outside. Same for the dryer. If you vent a dryer into a attic space, you are waiting for a fire to happen, plus the lint turns rock hard because it holds so much moisture. As for the Bathroom, you also vent it to the outside, because again, you do not want warm moist air staying in the space. Mine vents out of a attic vent that is made for Bathroom exhaust units.


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## koz123 (Jan 17, 2011)

gregzoll said:


> It needs to vent outside. Same for the dryer. If you vent a dryer into a attic space, you are waiting for a fire to happen, plus the lint turns rock hard because it holds so much moisture. As for the Bathroom, you also vent it to the outside, because again, you do not want warm moist air staying in the space. Mine vents out of a attic vent that is made for Bathroom exhaust units.


Ok, so I need to cut holes in my roof, install vents, and pipe the exhaust fans directly to them? Is it possible to just extend the existing duct work closer to the existing roof vents or do they need to have their own dedicated vent?

Thanks for the help.


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## gregzoll (Dec 25, 2006)

In your case, I would just exit them out of a sidewall in the attic. Mine was done when our roof was done about three years ago, which made it easier to have the vent put up on the roof.


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## hvac_dude (Jan 14, 2011)

Hey Koz, I been there before. Some homes built around the 70's- 80's esp townhomes in mid atlantic area do have exhausts to the attic NOT the roof. Generally exhaust fans pull air into the attic. From basic physics laws, you know that air is being replaced somehow right? This means air from other rooms is filling into the bath thus clearing moisture, If you have long, hot steamy showers and there is no window in your bath, ensure the fan runs long enough to exhaust the damp air. Also some condensation on the ceiling is common, You or the wife have to go up once a month or so and wipe it off with clorox/water solution to remove it, else it will turn into mold.
The issue on the attic air is ok and within code. You can just extend the pipes further up. Your attic fan or roof ventilation will take over from there.


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## koz123 (Jan 17, 2011)

Thanks hvacdude.

After discussing with friends and co-workers I've found that this is fairly common in my area. Here's what I'm thinking as far as path forward:

1. Extand my vent ducts away from wood and closer to the roof vents.
2. Re-paint bathroom ceiling with mold resistant paint.
3. When I get my roof done (within a couple years) having them add vents in the roof for my bathroom vents.

Also I'll take your advice with wiping the ceiling monthly or as needed to avoid mold.

Does that seem logical?


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## WaldenL (Jan 9, 2009)

hvac_dude said:


> ...The issue on the attic air is ok and within code.


I really hope you're wrong, but sadly I wouldn't be surprised if you're right that venting a bathroom into the attic meets minimum code. But I'm damn sure it's not a good idea!

koz123: You're long term solution is the right one, vent the bathroom outside, through the roof. If you're "a couple years" away from a new roof I'd consider having someone come in sooner and cut a vent for you, it's relatively simple. At a minimum I'd get some rigid pipe (not the flexi driver vent crap) and extend that vent right up "into" an attic vent until you can get it done right.


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## Michael Thomas (Jan 27, 2008)

You do NOT want bathroom fans venting into attics.


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## rhayward (Jan 19, 2011)

A few years back, when I was relocating, the home inspector wrote me up for my bathroom fans venting directly into the attic. The house was built around 2000 and it was built to code at the time. The inspection was in 2005 and by then the code had changed. To fix this, I installed vents into the aluminum soffit nearest to the bathrooms. You can buy a soffit vent kit at your local home improvement center. They only cost a few bucks for the materials but in my case, I had to hire it out because it had to be done quickly and I did not have the time to do it myself.


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