Prepping Basement Walls for Drywall
This Old House general contractor Tom Silva reviews his best practices when building out walls on a concrete foundation
Taping a small sheet of plastic on a concrete wall for a couple of days is a good way to determine whether any moisture is coming through. (You can also use the same technique on concrete floors.)
Hydraulic cement is the best way to patch any leaks or weep holes in the wall because it expands as it dries instead of shrinking like regular cement. All the smallest cracks get filled.
After using polystyrene foam adhesive to glue sheets of foam insulation to the walls, I attach two layers of 1x3 strapping—one vertical and one horizontal—to the rigid sheets. You could get by with just one horizontal row, but the 1½ inch thick grid made by the two perpendicular rows makes it real easy to rig electric and cable lines.