Basements (7 of 9): Exterior Walls

Most people, when finishing their basement, want to cover the exterior masonry walls.  After all, who wants to stare at a mass of rough, gray, cold wall?  Furring out the wall (built-out framing) will remedy this quite nicely, but before this is done one must verify that there is proper drainage at the base of the wall.  This is not easy to verify because the drainage is buried under several feet of dirt.  If you have a newer home you can check the plans on file or check with the original builder.  The reason you want to have proper perimeter drainage is because you will not be able to tell if there is water leaking through the wall once you have covered it up.  So, assuming you have proper drainage you have several ways to finish the walls.  One that is not recommended but seems to be popular with most do-it-yourselfers is to “glue” drywall to the surface of the concrete.  (Yikes!)  This is not recommended because any movement of the wall will result in cracks in the finished material, which inevitably results in pounds of mud (or drywall joint compound) being plastered over the crack over many years.  Another, only slightly better method, is to attach furring strips to the concrete and then secure gypsum board (drywall) to the furring strips.  A couple of flaws with this is that most do not think of providing treated wood (as discussed in an earlier post) and with the furring strips securely fastened to the concrete you still have the same issue of cracks due to any wall movement.  For the best results, use the floating wall method described in the previous post with an air gap of about one inch between framing and concrete.  This allows the wall and floor to move without interfering with any finishes.  The expense is a little more up front, but you don’t have to worry about trying to cover-up the mistakes of poor installation over the years with mounds of mud.