Is drywall required by code or can I use other materials to cover walls and ceilings. By code I think PA uses the IBC 2006. Thanks todd
I think it's required in some areas for fire protection. You can put other materials over the drywall.
Normal living spaces do not necessarily require sheet rock, but that could also vary with local rules. T&G wood, 1xsomething is allowed here except for furnace rooms where you need 5/8 type X. The IRC says wood is okay as long as it's thick enough, otherwise sheet rock under it is required.
There are a couple PA members, perhaps they will see this and know the answer.
The underside of enclosed stairs has to be 'rocked, and its a good idea even if the area isn't a closet. This is to buy them time in a fire.