Other than color change and deterioration, how can one identify FRP plywood? Is it embedded in the APA identifying code stamp?
FRP to me is Fiberglass Reinforced Plastic. That’s the danger of using abbreviations and non.generic terms. I assume you’re referring to Fire Reistant Plywood. If it is stamped at all, it would be stamped by the processor who applied the fire-resistant chemistry, and not by APA, which would stamp the grade of plywood but not any subsequent treatment.
Hi. Richard and yes that is confuseing.
Typically, FRTP is the common abbreviation for fire retardant treated plywood.
Here is a link that might help mschniers post above.
http://www.cwc.ca/NR/rdonlyres/77351FA7-CC2B-480B-8EF4-0DCC5379D17A/0/FireRetardantTreatedWood.pdf
Hope that helps.
Marcel 
arcel,
Marcel
Thanks for the link. You always seem to have the right ones!:mrgreen:
Randy