Since ROCKWOOL’s texture is similar to bread, the company recommends a normal bread knife to cut the boards. [2] X Expert Source Ryaan TuttleHome Improvement Specialist Expert Interview. 24 September 2021. A drywall knife will also make quick work of any ROCKWOOL boards. [3] X Research source Some contractors recommend using a small handsaw to cut through the boards.
An electric knife is also easier to maneuver, so if you have to cut the boards into shapes to fit around fixtures, this is a great option. Do not use this knife to cut food without washing it thoroughly first.
If you’re cutting on a floor and need to protect it, put a flat wooden board down and cut the ROCKWOOL on top of that. Make sure the ground is dry before pressing the ROCKWOOL down. It’s okay if the ROCKWOOL does get wet, but dry it out completely before you install it. [9] X Research source
The manufacturer recommends wearing at least an N95 respirator to prevent dust from getting into your lungs, so a regular dust mask won’t cut it. If you can, keep the windows open while you’re cutting the ROCKWOOL too. This filters out any dust in the air.
For example, if you want to install a board that’s 24 in (61 cm) across into a section that’s 18 in (46 cm), then cut 5 in (13 cm) off the board so it’s 19 in (48 cm) in total.
Normally, you’ll have to cut the ROCKWOOL lengthwise to fit between studs or ceiling rafters. You’ll then have to cut the next board widthwise and lengthwise to fit beneath the first one.
