Ridge vents on dormers?

Hi, I built my garage and couldn’t find a contractor to shingle it before winter… So I decided to do it myself. Now I’m writing to the experts on a forum - go figure.
The roof pitch is 10/12 with 2 doghouse dormers with the same pitch. My problem is that I sheeted it with the intention of using ridge vents (cutting 1" of sheathing from the ridge line). The reason for ridge vents is that I didn’t like how the regular vents look, as my house is butchered with them.
My question is: Can I use ridge venting on the dormers tying into the main roof? Its the low profile stuff, 3/8" thick maybe. I figured I would run it up the main roof (6" maybe) with my cap shingles.

Comments/suggestions? Help please.

Stop the ridge vent BEFORE you reach the main roof. 10/12 is fairly steep so I would keep them back 18" or so.

If I stop the ridge vent, how do I shingle over the peak where the ply has already been cut back the 1"? If I just lay cap shingles, the peak is then rounded.

Scab a couple of strips of plywood in there to bridge the gap. It won’t be noticable. Make sure you run a few cap shingles in under the ends of the vent.

roofing.com/forum/about6954.html :smiley:

If the attic space from the dormer roofs is connected to the main roof attic and they are lower than the main ridge line, then Do Not add Ridge Venting to the dormer ridge lines. They will short circuit the ventilation flowage.


I read that sticky about tying the dormer into the main roof… Thats what brought me to the site!
About the dormer vent interrupting the airflow, I then should not have a vent on my dormers, but have the soffits vented and use the “egg crate” vents to bring the hot air from my dormer to the main attic? Is that the way it should be done?
It snowed here the last 2 days so I tarped up the top 2 feet of my roof. Hopefully it melts and I can get back up there before winter really gets here (Winnipeg, Manitoba, Canada).

If you have a cathedral/vaulted ceiling in the dormer, then that attic or rafter bay area is not connected to the main house attic area and should then be vented.

I believe you were referring to insulation baffle vents when you mentioned the egg crate styled product.


Correct baffle vents and there is an attic space, it’s not vaulted. I’ll tie the 2 together and vent the main attic only. Thanks