A fireproof wall panel doesn't have to use ordinary normal-weight concrete. Thanks to inventors in Florida, autoclaved aerated concrete (AAC) can be used as a finishing material.

On June 15, 2002, inventors Frederick Browne Gregg of Leesburg, Fla., and Leslie G. Bromwell of Auburndale, Fla., received a patent for their "Method for Making Wallboard or Backerboard Sheets Including Aerated Concrete." It now is assigned to Consolidated Minerals Inc. of Leesburg, Fla.

The aerated concrete wallboard has a relatively low density of about 25-40 pounds per cubic foot. This means that even a 1-inch-thick, 4x8-foot wallboard sheet may have a relatively low total weight of about 60 pounds. And the design intent is such that these boards are installed with standard fasteners or adhesives in the same fashion as gypsum boards.