I just saw your post on your cathedral cold roof and hope it isn't too late to jump in. I had the same problem on an oblong shaped turret, cathedral stick framed with 2x12 rafters. All the end rafters dead ended on the end of the ridge on either end. Once the jack rafters were installed how do I get air in these dead spaces. Did alot of research but this is what I came up with. The roof will be a metal with a continuous ridge filter vent by AirVent.com giving 18 squares inches net free per foot, at the soffits I used the AirVent continuous soffit vent, giving 9" nfa per foot. I will seal the rafters with 1" rigid foam as you were going to do, but a company makes a neat little clip that eliminates nailing up 2x2s along the rafter to hold the foam down to create a airway. It's called the Corwin Smart Clip. The foam and clips are installed completely from the "bird Blocks" to the ridge and all gaps and spaces foamed closed. Now you have a completely sealed cold roof. To get air to penentrate to all the closed rafters and jack rafters without drilling holes, they also make a nifty product called the Corwin Rafter Vent which can be let into the rafter or installed on top of the rafter and a 2x2 filler added to the remainer of the rafter. I installed them on top and filled in. Check out their site at: http://www.keymarketing.us/products.shtml The picture attached shows the rafter vents in action. It sure solved a problem that is always coming up. Download Attachment: RafterVents.jpg 24.19 KB
