[Greenbuilding] mold question

[Benjamin Pratt]

Regarding plaster and sheetrock. Once plaster is set up, it can be soaked in
water and dried out numerous times without any problems. Like concrete, it
undergoes a chemical reaction which causes it to harden. I'm not a chemist,
but I've seen plaster sit around wet for weeks without any mold growth or
even bad smell. I think there is nothing there or the mold to feed on and
may be something there that even inhibits it.  The paint may peel, but the
plaster beneath is is often just fine after getting wet. It is, in many
ways, like concrete.      Sheetrock has a severl issues when it gets wet--it
is covered with paper which molds seem to love. It is thin, can warp and
lose it's structural integrity if left wet for some time. The screws and
seams are also covered with sheetrock compound, "mud", which can turn back
to mud when wet--it does not permanently "set-up". I have seen a wet
sheetrock ceilings fall down under their own weight when wet. I have seen
also seen plaster ceilings--such as the one in my garage stay intact--even
when the roof above it was allowed to leak for years.    There are lots of
people on this list who are more knowledgeable and smarter than I. I'm sure
they can give you more facts and calculations to support this. My knowledge
comes from being a professor in art and design who has used plaster and
sheetrock compound a lot, from being a person who has fixed-up a couple of
old houses, and from having a best friend who is a master "taper"-someone
who has worked with sheetrock and plaster for years.
    Also I had a recent water intrusion incident in my own home and
researched this issue intensely. I have seen more harm than good come from
an ignorant company tearing out plaster and creating lots of airborne
pathogens without protecting the rest of the house. If could do it all
over--I'd dry out the plaster as quickly as possible--in my house from the
attic above--but not tear it out unless it was falling down. l wouldn't
stir-up lead paint, vermiculite (with asbestos content) insulation, and
dormant mold spores which exist in nearly every old house.

-Ben