We have an L-shaped staircase that is against a basement wall where moisture rises at the bottom. In the corner of the L against the wall, there is currently a support, a beam that is about 10 cm in diameter (perhaps dimension is the correct term for square beams?). Anyway, this stands in the corner and is exposed to both ground moisture and moisture from the wall and looks anything but fresh. My idea is to remove the lower part of the L-staircase and replace it, as well as place plastic spacers between the staircase and the wall. But what should I replace the support with? One thought is to place roofing felt under and behind the beam against the walls (it's in a corner that no one will ever see), but I would like to hear if there are other good/better suggestions?
