This may be a little off the wall, but what about using some ice and water shield as is used on a roof? Any fasteners you put through it would be sealed, and it would prevent squeaks or grinding noises if the wood moved against the concrete. Hassle is, a whole roll of the stuff is kind of expensive to only use a little bit. the hassle with wood on concrete is that concrete can wick moisture and create problems with untreated wood. if you isolate it from the wood, you should eliminate that problem.