If you have an older home that does not have insulated walls, you can make your house more comfortable and energy efficient by installing blown-in insulation inside all of your exterior-facing walls. It is a fairly easy project, but can be a little dusty when installed from the interior of your house. Plan ahead and make sure you line up a few helpers.
Blowing in insulation from the interior of your house involves four project phases. First, locate the spaces in between wall studs and drill holes. Then fill the spaces with insulation. Next, you will patch the fill holes. Finally, a few coats of paint will put everything back to normal.
About 6 inches down from your ceiling, slide a stud finder across the wall to locate the studs. Mark both edges of each stud.
Select the point in between each pair of studs and drill a hole about 1-1/4 inches in diameter. Make sure you are about 6 inches below the ceiling to avoid the top plate inside the wall.
Once all the holes are drilled, you are ready to start filling each space with insulation. Have a helper control the insulation blower from outside the house. Run the hose through a window into each room. Stick the nozzle into each hole and wrap a rag around the nozzle to prevent blow-back from the hose. Hold the nozzle and rag tightly in place and fill each space completely until the blower starts to struggle.
Once all of the holes are filled with insulation, you can start the wall patching process. Use your finger to push in the insulation to form a small pocket inside each hole. Then, fill the pocket with expanding foam filler, allowing a small mushroom-shaped glob of foam to expand beyond the wall surface.
When the foam has completely dried, take a long bread knife and saw off the foam mushroom flush with the wall surface.
Using drywall compound, put a thin layer over each hole. This will fill in the exposed pores of the foam patch. It may take two or three thin applications of drywall compound to completely smooth over the patch. When the drywall compound is dry, lightly sand it smooth before painting.
Now you are ready to paint and put everything back to normal. Use a primer/sealer to coat the the drywall compound. When it is dry, apply paint that matches the existing color of the room. That should do it! You are now ready to see your heating bills drop and enjoy a more comfortable climate inside your house.