Rockwool ( also called mineral wool) comes in easy-to-install batts, similar to fiberglass. But instead of being composed of fluffy glass fibers, rockwool is made of rocks.

Rockwool insulation can be installed wherever you would install fiberglass or any other type of insulation, including walls, floors, ceilings, attics and crawlspaces.

Rockwool is highly fire resistant.

It is also easy to work with: The firm batts can be cut with a serrated knife or handsaw to fit snugly into place.

If it gets wet, water beads up and rolls off without soaking into the fibers.

The rockwool fibers are compacted so tightly together that there’s no chance of the insulation shifting out of position or slumping down, which would dramatically decrease its insulating value.