I am finishing my first basement(I am just starting out in the remodeling business). I will be building 2 x 4 walls up against the concrete foundation walls, insulating them, and sheetrocking them to finish them off. My question is....where does the vapor barrier go in this situation? Does it get installed the usual way facing the interior of the building? If moisture would happen to enter through the concrete, wont it get trapped if the vapor barrier is installed this way? does it pay to use pressure treated lumber for this?