Will this work ?

[Arky217]

I am wanting to keep my metal roof from being penetrated by multiple vents.
I was wondering if this arrangement work; tying all the vents together in the attic and going out the gable end of the house.



Arky

[Bob S.]

I have a similar question. Would it work if you ran it up into a cupola at the roof ridge? You would have to make shure that the cupola was not vented to the attic.

[MountainDon]

I don't know why so many folks are afraid to drill or cut holes in their roof. The available rubber or silicone boots with a dead soft aluminum flange within the molded boot work very well on a metal roof. 

[MushCreek]

Since we're on the topic- How do you flash the boot to the metal roof? I ran into this on my barn. I had to put the vent in after the fact; the roof was already on. The base of the boot was a good deal wider than the space between the ribs, so I cut it down. I still don't know how to cut the roofing to get an overlap. Had I been able to do it during the roofing, I guess I would have cut two pieces of roofing so the upper could overlap the lower, with the boot at the transition. For the short term, there is no boot- just half a tube of silicon to keep the rain out. I do need to fix it, though. The other problem in my case is the very steep pitch- 12/7. It's the lower part of a gambrel. All of the boots I found were for 12/12 or less. Any thoughts?

[Don_P]

I don't like roof penetrations myself, what Arky is proposing looks like an allowable revent to me.
Can you run up the rafters to the upper pitch on the barn?