When installing fiberglass batts which is the correct method?
rockinroger
| Posted in Energy Efficiency and Durability on
I’ve always folded the paper flanges over each other on the stud & stapled.
I’ve seen some videos on You tube from major companies showing them stapling the flanges on the inside of the studs. It doesn’t seem right to me. It compresses the batt, & seems like it allows air leakage.I’ve always thought that if the flanges overlapped you get abetter seal & vapor barrier.
Which is the best way?
GBA Detail Library
A collection of one thousand construction details organized by climate and house part
Search and download construction details
Replies
Roger,
Builders have been expressing strong opinions on this topic for decades. Careful research has shown that the presumed thermal performance degradation from convection in the vertical air spaces created by stapling on the sides of the studs is extremely minor -- so minor it is hard to measure.
My advice: staple the kraft facing your way (on the 1.5-inch-wide edges of the studs) unless the drywall contractor wants to glue the drywall to the studs. If the drywall is getting glued, then switch to unfaced (friction-fit) batts, or staple the flanges the other way (to the 3.5-inch-wide sides of the studs).
There are lots of fiberglass batt installation errors that matter more than the issue of how to staple the flanges. For more information, see Installing Fiberglass Right.
Thanks Martin. I know that I can always count on you for the right answer.
Stay warm.