On Thursday, February 9, 2017 at 8:13:39 AM UTC-5, N8N wrote:
Hi all

got an issue at a friend's rented house

I helped move her in and noticed that neither bathroom vent fan was actually vented to outside, just output loose in attic

a few weeks ago a bad storm damaged the roof and I told her to mention to landlord that this would be a great opportunity to correct the bathroom fan venting, he thanked her for the suggestion and said that it'd be taken care of

well his "handyman" is an idiot. Apparently there was an abandoned 4" roof vent about 7-8' away from the large bathroom's fan, instead of recutting the hole in the ply that had been scabbed over in a previous roof replacement and hooking the bath vent up there he got some 4" flex duct and ran it all the way to the abandoned vent. He didn't do a thing to the small master bedroom's fan, it is still unvented. The whole mess is not held together with proper transitions or clamps, it's all duct tape and fail. What a ****ing hack job.

At this point I see that the handyman is cutting corners wherever the owner isn't cognizant of what a proper job should look like and that this job is probably never going to get done properly. I know the *right* way to do it is to get up on the roof and install a new vent but I don't want to cause friction. At the same time I don't like the potential for mold and mildew that the current arrangement creates.

What I'm thinking of doing is just not talking to the guy and getting some proper 3" flex duct, and a 2x3" to single 4" y adapter and hooking things up that way. It'll still look like a knot in a canine's genitalia but at least both fans would be vented to the outside.

Questions: would this meet code? Is there any downside to doing it this way other than being ugly and messing up the attic space?

thanks!

nate

I've never seen two joined together, but that doesn't mean that it's
not done or not code. One obvious issue is that what happens when only
one fan is on? They have a flap in them that is supposed to close when
not in use, so I guess that would prevent one fan from blowing back into
the house via the other. For a rental and given the situation, your plan
seems to be a reasonable one.