DIY Chatroom Home Improvement Forum

DIY Chatroom Home Improvement Forum (http://www.diychatroom.com/)
-   Roofing/Siding (http://www.diychatroom.com/f9/)
-   -   Bathroom vent directly over a rafter (http://www.diychatroom.com/f9/bathroom-vent-directly-over-rafter-39876/)

Kirgan 03-08-2009 12:24 AM

Bathroom vent directly over a rafter
 
I just had a re-roof. The roofer also installed attic vents & two bathroom vents. I was going to install the bathroom vent fan along with the ducting up to the vent the roofer put on the roof.

One of the bathroom vents was installed partially over a rafter, instead of in between two. There is enough of the hole showing that I could take a 4" duct and slip it in (with only slightly having to bend the duct). There would then be a slight hole over the rafter leading up to through the roof into vent.

The roofer says that will be fine and just install the duct and use foam to fill in the visible hole around the duct. Does this sound right to you or should I force the roofer to remove the vent and move it over in between the two rafters? If I force the roofer to move it, I had wondered if that would be worse than installing the duct to the vent where it is now, since if they move it, they would then have to somehow cover up the previous hole.

Thanks for the input,

--Mike

tinner666 03-08-2009 09:59 AM

If the hole is just the gap between the rafter and the roof material, where a piece of decking is missing, you should be alright. Hard to tell without pictures.

Ed the Roofer 03-09-2009 02:04 AM

The ducting is supposed to fit tight with no broken seal, for all of the moisture to exhaust out of the attic compartment.

Incorrectly hooked up ducting or the use of the wrong type of roof top exhaust vent are very common minor problems that cause major interior mold damages and lessening of the insulations R-Value.

Make sure it is done correctly with the correct type of vent, specifically made for an exhaust fan.

Just thinking about how dumb it was, for the guy to continue his cut directly above a rafter which will now diminish the size of the ducting outlet potential, makes me wonder if it will function correctly.

Ed

Kirgan 03-09-2009 11:07 AM

Here are two pictures. The two silver vents are the ones for the bathroom vents. One bathroom is directly behind the other - hence the reason the vents are so close to each other. The brown vents are the standard attic vents they used.

There is also a picture of the hole that is right above the rafters. As you can see part of the hole is covered by the rafters. The roofer told me to just put the insulated ducting in the hole and the seal the gap that goes overtop of the rafters with foam.

I have the choice to follow his directions or make them redo it, which I assume means he has to tear off that section of the roof, put down new plywood, felt, water barrier and new shingles again -before he cuts a hole in a new location.

What do you think?

http://www.flickr.com/photos/aquatic...er/3340837265/

http://www.flickr.com/photos/aquatic...er/3340837275/


Thanks,

--Mike

tinner666 03-09-2009 04:24 PM

That won't work. A bathroom veht should have a neck to attach the hose too. I made a wrong diagnosis based on the info in your opening post. I though there was a neck sticking out and you could just see a gap beside it.

I'd have him get bathroom vents and install them. Read Ed's post.

Kirgan 03-09-2009 10:37 PM

I knew there was supposed to be a neck and I had originally thought the vent should have a preattached neck when it is put in. The only ones I have seen through various DIY web sites already included the neck attached to the vent.

But this roofer was trying to tell me that you can put in the neck from underneath (by bending it a bit due to the hole being over the rafter) and then attach the ducting to the neck. And they said put foam around the neck to ensure there is no part of the hold directly over the rafter that isn't filled in with foam.

I wasn't sure I believed that when they told me, so I did some research. First, I looked up the vent the used online and the description said it was commonly used to vent bathrooms and kitchens. Even though I read that, I still wondered if it was accurate, since if the neck wasn't preattached, I didn't know how well it would stay in place. I certainly didn't want it to come out of the vent over time.

So, since I still had doubts about what they said, I posted here to get feedback.

And thanks to both of you for the feedback. It sounds like I really should make them redo this work - by moving the vent away from the rafter and by putting in a vent with a pre-attached neck. And then I can do the rest. Or maybe I should just redo the whole thing myself. I didn't think I could do the whole roof, but maybe I can do just the vents myself.

--Mike

Ed the Roofer 03-11-2009 02:30 AM

Quote:

Originally Posted by Kirgan (Post 242507)
I knew there was supposed to be a neck and I had originally thought the vent should have a preattached neck when it is put in. The only ones I have seen through various DIY web sites already included the neck attached to the vent.

But this roofer was trying to tell me that you can put in the neck from underneath (by bending it a bit due to the hole being over the rafter) and then attach the ducting to the neck. And they said put foam around the neck to ensure there is no part of the hold directly over the rafter that isn't filled in with foam.

I wasn't sure I believed that when they told me, so I did some research. First, I looked up the vent the used online and the description said it was commonly used to vent bathrooms and kitchens. Even though I read that, I still wondered if it was accurate, since if the neck wasn't preattached, I didn't know how well it would stay in place. I certainly didn't want it to come out of the vent over time.

So, since I still had doubts about what they said, I posted here to get feedback.

And thanks to both of you for the feedback. It sounds like I really should make them redo this work - by moving the vent away from the rafter and by putting in a vent with a pre-attached neck. And then I can do the rest. Or maybe I should just redo the whole thing myself. I didn't think I could do the whole roof, but maybe I can do just the vents myself.

--Mike

Thank you very much.

Please report back to us as to how things wind up turning out, okay.

Also, if it was not in their contract to install the hook-up, they could possibly out of liability for this, but from a legal standpoint, once they assumed the liability of doing that particular installation, they also assumed the liability of doing it correctly, by manufacturers specifications and per code requirements.

Moisture escaping into a hot and already humid attic environment is just asking for potential mold problems.

Ed


All times are GMT -5. The time now is 06:53 PM.