replacing drywall with dry things

6.2: gear/drywall/sand & metal:

. cheap fireproof and wetproof drywall could be done by

metal sheet panels bent and crimped in the shape of drywall,

then filled with baked sand;

or when used as panels on the ceiling,

filled with something lighter like perlite .

. not as easily cut into odd shapes like drywall is ..

6.4:

. pieces would have to be prefab'd per architecture req's .