We are beginning the very slow process of finishing our basement. We already know we have a radon issue and plan on installing a pump. From what I have read, it makes sense to seal all cracks in the floor and gaps between the floor (poured concrete) and perimeter walls (block) so that the pump isn't drawing inside air. We don't have too many cracks/gaps and those we have are small (<1/4 inch). The basement is dry so I am not sealing for water. Since it makes sense to do all this now, before framing, can you help me understand what kind of caulk/sealant might be best? Thanks. This website has solved many problems for us.

I just moved into a home that has unfinished basement stairs. Meaning, they have the part you step on, but not the back part of the stairs. I want to finish them myself. It seems like it would be easiest to hammer a piece of wood to the front, but then that would make the stairs more shallow. What is the correct way to finish the "back" portion of the stairs off? Placing the wood from the front or the back of the "back" portion of the stairs? Hope this made sense. Also, what type of wood and how thick? Thanx, :p