How do I staple faced insulation to ceiling joists if the flange has been cut off for narrower spaces?
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&quot; in length (a bit more so they're snug) and running them crosswise.