How to Add Wall Insulation
Adding wall insulation is a way of increasing the energy efficiency of your home, saving money year-round and giving you one more plus if you are going to put your home on the market. Adding the insulation material from inside the home will require some drywall work, both cutting drywall material as well as restoring the wall surface. While you could hire a professional to do the job, if you’re a DIY-er, you can complete the process yourself. You’ll need the assistance of a helper to do the job right, but with help the job goes much more quickly, leaving you with an improvement that should last for the lifetime of your home.
Locate the studs in the wall where you’re placing the insulation using a stud finder. Mark the location of the studs with a pencil.
Choose a point centered between each pair of studs about 6 inches from the top of the wall and cut a 2 inch diameter round hole using a hole saw. Remove the drywall cutout and set it aside.
Run the nozzle on the end of the insulation blower hose through the hole between the studs. You can rent blowers from a home improvement store or equipment rental shop. Push the nozzle down the wall cavity until it’s about 2 feet from the bottom. Tie a piece of cloth around the hose at the entrance to the wall so that the insulation will be blocked in as it’s blown.
Have your assistant fill the blower and then turn it on while you secure the hose in place. As the insulation fills the cavity, pull the hose up and out of the hole, moving the rag along the length of the hose to maintain the seal at the hole. Have your assistant continue filling the blower with insulation material as you continue.
Have your assistant turn off the blower when the cavity is filled with the insulation. You can tell it’s full when you begin to feel that the insulation stops blowing from the nozzle, indicating the insulation material inside the wall is covering the nozzle opening.
Remove the nozzle from the hole and repeat the filling process with each of the cavities between the studs until you’ve filled the wall space with insulation.
Push the insulation material slightly back from the opening to create a small depression. Fill the depression with expanding foam sealer, sealing the hole completely until there’s a slight protrusion outside of the cutout area. Allow the foam to dry completely and then cut the extruding area off with a utility knife. Sand the foam level with the surrounding wall surface.
Cover the foam with a thin layer of drywall compound using a putty knife. Place a piece of drywall seam tape over the foam, pressing the tape firmly into the compound, and then smooth out any excess compound using the putty knife. Allow the patch 12 hours drying time.
Place a slightly thicker layer of drywall compound over the patched cutout and feather the edges over the wall, surrounding the cutout by about an inch, thinning out the compound as you move away from the cutout. Wait 12 hours for the new layer to dry and then sand it smooth, removing any evidence of the edges of the cutout or the seam tape.
Wipe the surface of the cutout patch with a damp sponge to remove traces of sanding residue. Paint the patched area with primer paint and allow the primer two hours drying time. Cover the primer with paint the same color as the surrounding wall to hide the cutouts.
- Wear safety goggles and a facemask or respirator when pumping the insulation materials into the walls to prevent inhalation or eye irritation.
- Do not use the insulation material in cavities containing a chimney or a light fixture as the heat generated can possibly cause a fire.