I am building a Cape Cod style garage apartment and the plan I have shows a gable end vent on the cover drawing of the building but the plan itself doesn’t show any vents on the gable ends. The roof is a 12/12 pitch and I will use a ridge vent if I can find one that will work on this pitch, and soffit vents with vent channels between the 2X8 rafters. I am building the gable walls and don’t know if I need end vents or if the soffit and ridge vents are sufficient. The bottom line is that I don’t know the mechanics involved in attic ventilation. The building will have a large 4.5/12 pitch shed dormer in the back and 2 small gable dormers in the front. Any help will be greatly appreciated.
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forget the gable end vents they just fight with the soffit / ridge vents
what size are your rafters?
Mike Smith Rhode Island : Design / Build / Repair / Restore
Most capes don't have a soffit. They can be hard to vent right. Course some say don't vent, some say do. I like fresh air moving around myself.
The rafters are 2X8-18' long with a 10" overhang of the building. The soffit will have a continuous vent along the length of the building.
sounds like lots of room...the restriction across the knee wall is one choke point..
in the flat attic area you can put as much insulation as you can cram in.. most people try to use the space behind the kneewall as extra storage.. so that restricts the amount of insulation you can get in..
in our 6000 DD. climate I would use vented vinyl soffit... Propa-vent air channels from the soffit to 12" above the top of the attic insulation.... 18"- 24" of cellulose in the attic.... 1" EPS Performaguard foam (2 lb. / cf) on the bottom of the rafters and furr the sloped areas.. then I would blow the rafter bays thru the foam with Dens-pak cells.. all of the area behind the kneewall would be useable and within the living climate controlled space..
and Shingle -vent II ridge vent ..from gable to gable..
Mike Smith Rhode Island : Design / Build / Repair / Restore
Thanks for the help Mike. I live in Oklahoma and I have been reading this forum for about a year. I was interested in the thread about where most of the contributors live and realized no one from Oklahoma had a post. It seems there is a vacuum of talent in this area. I called several plumbers and general contractors before I started this project and only one general showed up although several made appointments and then didn't show. It seems that the talent is concentrated on the coasts with a few pockets of knowledgable builders over the rest of the country. Oh well, just an observation. Thanks again.
randy.. there was a builder from the Norman area that used to post on the old BT..
BTW.. one of my sisters lives in Norman.. and I spent 3 years at Sill.. good memoriesMike Smith Rhode Island : Design / Build / Repair / Restore
Randy...are you still here?? I know the post is old but just wondering....If you aren't one of the one's I'm talking about,you shouldn't have any complaints....