I'm insulating a detached home office/shed. For the ceiling, the rafters are 24in on center so I got 22" faced insulation for that. However on the ends of the structure, the rafters are only 21in on center so I have to rip the insulation to fit. This means the little paper flange for stapling will be cut off. How do I staple that side to the rafters then?
1 Answer
Option 1
Cut the fiberglass but not the paper. You could do this by pulling the fiberglass off the paper, sliding a protective sheet under, then cutting the fiberglass.
Option 2
Cut the batt, then add adhesive tape as a flange. Use fiber-reinforced paper packing tape or something similar that won't easily tear when you staple it.
Option 3
Use unfaced batts there and then add poly sheeting. Reduce waste by cutting the batts to 19-1/2" in length (a bit more so they're snug) and running them crosswise.