How to Cut Fiberglass Insulation Batts

Prepare space on the floor

• To avoid damaging the floor underneath, use a full sheet of plywood or subfloor to cut the insulation on.
• If your remodel doesn’t yet have a floor, that’s even easier – cut it right on the subfloor.
  • PRO TIP: If you’re cutting many bats at the same length, make some marks on the plywood so you don’t have to measure every single batt.

Article source here: How to Cut Fiberglass Insulation Batts