Adding basement insulation to a basement whose foundation is cinderblock is a necessity if you live in a cold climate. Without the insulation, your basement will be less resistant to the cold outside air. Consequently, you will find that heating your basement can be much more costly than you desire. To avoid that, add a good insulation to your cinderblock walls. To complete this project, refer to the following information about insulation installation, materials, and tools you'll need.
Step 1 - Determine the R Value of Insulation You'll Need
Depending on the climate you live in, you will need insulation with thermal resistance rated anywhere from R-3 to R-21. Charts that will provide this information are available online and at your local home improvement store. Compare the various types of available insulation and note which of them offers the R value you need. Purchase rigid board insulation with the desired R value.
Step 2 - Install Furring Strips
Determine the total width of all exterior walls on which you'll be adding your insulation. Divide this figure by 16 to determine the number of furring strips you’ll need to attach to your wall. Buy or cut your furring strips to the length you'll need to attach each of them from your basement floor to your ceiling joists.
Snap a vertical chalk line every 16-inches on your cinderblock wall. Make sure these lines are plumb. Drill holes into one of your furring strips through which you'll insert masonry screws. Hold the furring strip in place against the wall and mark the location of each hole along the wall. Using your masonry bit, drill a hole into the wall block where you made your marks. Then screw masonry screws or concrete screws through the furring strip into the wall. Do the same for each furring strip.
Step 3 - Cut, Glue, and Caulk Your Insulation Boards
Cut your insulation board to fit between your furring strips. In areas where pipes or cable enter your basement through walls, cut insulation to fit in spaces that are oddly shaped. Glue these pieces into place.
Apply a .25-inch bead of adhesive to the wall where your insulation boards will be attached. Press your insulation board into place between the furring strips. Fit your cut insulation boards as tight as possible between the furring strips to prevent cold air from entering these spaces.
Glue these strips to the wall using foam insulation adhesive. Once they are glued in place, fill with caulk all the spaces between the boards as well as the spaces where you glued the odd shaped insulation pieces and the furring strips with caulk.
Step 4 - Install a Vapor Barrier
When your adhesive is dry, cut and attach a plastic sheet to your newly installed insulation. This sheet will act as a vapor barrier to keep out any moisture that might be entering through your walls.