On Sun, 11 Jan 2009 14:03:20 -0500, "Ed Pawlowski"
wrote:


"EXT" wrote in message
tanews.com...
Because foam board is flammable, I understand that in all cases, it must
be covered with drywall to make it fire resistant. This certainly would
apply in a furnace room, probably more than any other room.


Not classified as flammable. It will only burn if there is another source of
ignition (such as a defective furnace) but will not support combustion on
its own. Take a small piece outside and set it on fire. Take away the
lighter and it will go out in a few seconds. .

True - HOWEVER, when exposed to flame the resulting smoke is TOXIC -
and by code it MUST be covered - anywhere, furnace room or not. I'd
cover it with sheet-rock - 1/2 inch or better in the furnace room.