History of gypsum board

We have recently received a watercolour on paper that is adhered
overall to early plasterboard (gyprock).   A label informs us that
the painting was exhibited in the 1930s.  We are trying to determine
if the watercolour could have been adhered to the plasterboard by
the time it was exhibited or if it was adhered to the plasterboard
at a later date.  A second watercolour in our collection is also
mounted on (or painted directly on) plaster board.  We know from a
label on the back of this work that the gyprock in this case was
produced in Montreal, Canada.

Can anyone give me information on the history of gyprock that could
help determine how early these watercolours could have been mounted?
I have found some information on the Internet.

One source states that "In the mid 1900s [Nova Scotia gypsum]
production increased dramatically with the invention of wallboard,
more commonly known as gyprock."
<URL:http://www.gov.ns.ca/natr/meb/ic/ic16.htm#04>)

Another says that "with the advent of [World War II] ... any
mechanised process which could release men from the workforce to
fight was embraced... These conditions brought about the creation of
Plasterboard" <URL:http://www.chrissavage.com.au/history2.htm>.

But a third says that plaster board was invented in 1890 in New York
and was already popular, at least in then U.S., by 1909
<URL:http://www.gpda.org.uk/student.htm>.

I'd appreciate hearing from If anyone who has more information about
Gyprock history.

Karen Potje
Head, Conservation/Preservation
Canadian Centre for Architecture


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                  Conservation DistList Instance 18:51
                  Distributed: Tuesday, April 26, 2005
                       Message Id: cdl-18-51-035
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