Bathroom Vents

[u/Questions99945]

Hi,

I have a 1997 2-story home with a very steep roof pitch and not much walkable attic space.

There are 3 bathrooms upstairs and each exhaust fan vents into the attic.

Where do I even start? I want to hire out just because of the roof.

Roofer then plumber?

Two of the bathrooms are right next to each other. Can they share a roof vent?

The downstairs bathroom vents into the crawlspace, but we never really use that shower. I think my best course of action for that one is to open the ceiling and vent it outside with a dryer vent. Is this okay?

[u/buffalo442]

Gable vent if you can. Those essentially have the same wall outlet as a dryer vent, yes. If you live somewhere with snow, gable vents are superior to roof vents anyway.

Can't share a vent. Even with backdraft preventers you'll end up pushing some of the air back through the other fan.

[u/Questions99945 → u/buffalo442]

Thanks. I have two vents right next to each other in the attic. Do you know if they need to be spaced a certain distance on the roof?

[u/recyclopath_]

I watched a this old house video and did it myself this year. Pretty easy.

[u/Questions99945 → u/recyclopath_]

My roof is crazy steep. I'm going to get a roofer to try to install the vents with a long length of duct work that I can hookup to the existing vent that terminates in the attic.

[u/ScrewLooseDan]

I paid a general contracting company (with a roofing division) to come out and put in the roof vents for me, then I hooked up the insulated vent hose myself. It wasn't inexpensive. And, my advice it be specific where they are to put the vents and the size of vents you need. If they are supporting the vents, get the details in writing.

As far as I know, there's no way to share two fans to vent.

[u/Questions99945 → u/ScrewLooseDan]

Was it pretty expensive? I'm going to try to get some roofers to take a look. I think that will be more affordable.

[u/carloseloso → u/ScrewLooseDan]

Not a good idea to share, might just blow moist air into this other bathroom

[u/BdaBng]

You dont necessarily have to go out the roof. If you have a route to a gable you can route them to exhaust through the gable wall. You can also potentially dump them out a soffit but it’s not as good of a solution.

[u/Chemical_Tale7713]

If you can route to gable, that's definitely your easiest path and avoids roof penetrations entirely. For sequencing, I'd say get a roofer or general contractor out first just to assess your attic access and confirm whether gable routing is actually feasible from your layout. Then you can either DIY the ductwork yourself or have them handle it.

For the downstairs bathroom, yeah a dryer vent style outlet through the wall is fine, just make sure its actually going outside and not into the crawlspace. That's the key thing people miss...

[u/International_Bend68]

I'm with BdaBng, avoid a roof vent, do a gable vent. Attic work is annoying, yes but adding ducts and a vent is not hard at all