Sound deadening Material on the Cheap.

If the padding will absorb or trap moisture it is not a good choice.

x2. I know the padding under carpet will absorb water. I've been looking for something on the cheap too, and the best I can figure is they sell Dynomat for a reason. I tryed left over foam from a chiller install, which would have worked, but I left it in a bucket of water and it soaked water after 24 hours, so its a no go.