It's only a start but check out the NPS Preservation Briefs relating to plaster.  Here is a link to their publication list. Plaster on exposed stone is a common issue with Roman ruins so experts in that area are probably more useful than those working within interior spaces. 

 
http://www.nps.gov/history/hps/tps/tax/download/tax_tech_index_2008.pdf


Jerry Schaefer
 
ASM Affiliates, Inc.
2034 Corte Del Nogal
Carlsbad, CA 92011
760-804-5757 (office)
760-804-5755 (fax)
 
 


-----Original Message-----
From: HISTORICAL ARCHAEOLOGY [mailto:[log in to unmask]]On Behalf Of Gaye
Nayton
Sent: Wednesday, April 01, 2009 5:06 PM
To: [log in to unmask]
Subject: conserving plaster


Hi

 

I need to give conservation advice on an extensive set of stone ruins which
still have some scraps of plaster on their inner walls.  Does anyone have
any good advice on the best ways to conserve the plaster other than roofing
the ruins which is extremely unlikely to happen.

 

Regards Gaye

 

P.S. The weather in WA is hot and dry most of the time but when it rains it
tips down. So preventing water damage is a factor.