Any Code issue with using Plywood finish in Mech Room – GreenBuildingAdvisor

I don’t see an issue as long as you don’t have any particular local fire code requirements. Your local building department should be able to answer that question pretty easily.

Note that if you do use plywood here, I would recommend using “noncom” (Non-Combustible) plywood here for a bit of added safety. This stuff is dyed “red” (it often looks more pinkish though), and is treated with a fire retardant. Noncom plywood isn’t very common in the residential world, but it’s frequently used in the commercial world and it’s readily available, but you’ll probably either have to go to a “real” lumberyard to get it, or have a box store special order it for you.

BTW, why ACX in a mechanical room? Just save some money and use CDX. If you want to have a nicer finished surface, use a coat or three of high build primer to smooth out the surface and then paint normally.

Bill