Fiberglass Batt Cutting Guide
If you need to cut a bunch of small pieces of fiberglass insulation all to the same size, you could get your tape measure out every time and measure each piece, but there’s a better way. George MacEachern, of Vassar, MI had to insulate between floor joists at the mudsill of a house, so he came up with a simple plywood cutting guide that allowed him to cut dozens of pieces of fiberglass insulation to the exact same size. The cutting jig is simply a piece of 1/2 inch plywood with a slot down the middle wide enough for a utility knife. To use, you just lean on the plywood to compress the batt, and then cut the fiberglass batt. One side of the jig is sized to cut batts to fit in 2×10 floor joists, and the other side is sized to cut batts to fit 2×12 floor joists.