I want to leave my basement stairs open but an thinking about drywalling the underside. I can attach a fir strip to the side rails....it would not exactly sit flush because the actual stairs pertrude out a little past the rail. A long enough screw should secure the fir though, no? Would a stip on each end be enough to secure the 3' wide peice of drywall. Is this just a bad idea? nce done I could cover the drywall edge and gap with a piece of molding...