Basement walls need insulation if they are to provide thermal protection against cold air that will otherwise enter your basement through exterior walls. To install this insulation, you'll need to also install a frame on your basement walls. Follow these steps to install the framing for your basement insulation.
Step 1 - Cutting and Fitting Your Insulation Boards
Measure your ceiling from bottom to top. Cut your insulation boards to fit vertically against your basement walls. To attach the boards to your wall, apply a small amount of epoxy adhesive to the wall where you will glue your first board into place.
Hold the board vertically in place and push it firmly against the wall. Add your second board as you did the first, but be sure it is butted tightly against the first board. Follow this same procedure for your other boards until they are all in place on the wall. In odd-shaped places where your insulation boards won't fit, cut custom-shaped pieces and glue them in place.
Step 2 - Tape and Grout Your Insulation Board Seams
To block cold air that could enter the basement through seams between your insulation boards, attach a strip of tape vertically over these seams. Then apply grout to irregularly-shaped spaces where you have cut and glued board pieces to fit into these spaces. Wherever you find spaces or voids which are not covered by tape, fill them with grout.
Step 3 - Install a Bottom Plate
To attach a bottom plate for your frame to rest on, attach a 4-inch insulation board to the floor using epoxy adhesive. Apply the adhesive to the bottom surface of the plate. Then lay this board on the floor with its inside edge pushed securely against the vertical insulation.
Step 4 - Cut and Install Wall Studs
Instead of attaching your frame pieces one at a time against your insulation boards, cut the studs to fit between the floor plate and your ceiling joists. Nail them into place, spaced 16-inches apart and attached to the bottom plate. Apply epoxy adhesive to your frame's bottom surface.
Hoist the frame so that its bottom is resting on the floor plate and is pressed firmly against the adhesive. When you have the frame in a vertical and plumb position against the insulation boards, nail it into place by driving nails through the frame's top plate into the ceiling joists.
Step 5 - Installing Insulation on the Frame
Unroll the insulation you'll be attaching to the outer frame surface. Cut the insulation into strips which are the same height as your frame. With the vapor barrier side of the insulation against the frame, press it into place. Now all that is left to do is to install your drywall.