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I’m getting ready to insulate my new addition, and the family room has a vaulted ceiling. I was wondering should I continue the rafter vents all the way up to the ridge or stop at the ceiling joists? Also if using cells does the rafter vent collapse (plastic type) when dense packing. Would it be better or worth it to use 1/2″ rigid foam as a radiant barrier & vent in the rafter spaces?
Thanks,
David
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We installed the baffles from ave to ridge, then filled with cellulose.
*In a "bonus room" I used 1" foil-faced foam to make vents in the sloped ceiling. Lots of work. Your bays will not all be the same width -- you'll have to measure and cut each one unless you want big gaps at the edges. And how do you plan to attach the panels. I glued up 1" thick battens (cut from scrap pieces of the foam board) to form a 1" vent channel. Then a dollop of glue (F26) on each of these battens (actually 2" sq. blocks, placed every 2-3 ft) and then a 2.5" drywall screw (with a plastic cap). Bear in mind I have 5/8" roof decking, so my screws don't go into the shingles. Lots of work.My insulator would have just used the foam vents, but I'm in this house for life. Otherwise, I wouldn't have gone to all the trouble. Oh, the bays were furred out to 7.5" by my framer so I will still get 5.5" of cells in the slopes.
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I'm getting ready to insulate my new addition, and the family room has a vaulted ceiling. I was wondering should I continue the rafter vents all the way up to the ridge or stop at the ceiling joists? Also if using cells does the rafter vent collapse (plastic type) when dense packing. Would it be better or worth it to use 1/2" rigid foam as a radiant barrier & vent in the rafter spaces?
Thanks,
David