Expert: James Ball - 4/16/2009

Question
QUESTION: We removed plaster that was behind our fireplace.  It's attached to the back of the fireplace brick with a metal mesh and meets up with the lathes on each side of the fireplace, which is a finished area.  We wanted to put drywall in place of the plaster, but we are not sure if the plaster with the metal mesh was for of if it was for fire resistance.  Or can I install fire rated drywall in it's place.

ANSWER: Hello Pat, there are minimum clearance to combustibles Your local building department will have what you need for your town) but NFPA211 states (more or less)a fireplace must have 4" thick of fire brick then 4" thick regular brick, then 4" of air space (nothing in this area not even insulation) to combustibles out the back and 2" every where else on the sides over the mantel to the top of the roof line.
Sheet rock has paper on it and I do not know of any sheet rock that is fireproof it is a fire stop but it to must follow the clearance to combustibles.
when you opened it up you are not required to bring it all up to current codes
James

---------- FOLLOW-UP ----------

QUESTION: I still am trying to decide what I should do with it.  It was brick with a metal mesh with plaster on it then just paint in a finished area(Hallway).  Our town is small so they just refer you to the Universal Building Code and NFPA so they have no input on it.  The drywall I was referring to is a X rated drywall that has a mesh that is inside it.  Any help on deciding what to do with this would be greatly appreciated, especially since we have it opened up now.

Answer
Welcome back Pat, the key word here is "combustibles" and the clearance to them (in last post) if the sheet rock is "fireproof" then go for it if not then you will have to space it out 4" mim from the brick out the back of the fireplace.
You could have a local Certified Chimney Sweep (www.csia.org, there you can look up by zip code to find one near you) take a first hand look at what you have they should be able to help.
good luck and keep me posted
James