For new additions and remodeling projects, your choice of insulation will, no doubt, depend on personal preference, use of the space, and R-value necessary for your area. Fiberglass is most often used, although, in many areas, people are also installing rigid foam board on the outside of the frame underneath the siding, as well as fiberglass in the walls. Should you choose to use fiberglass, the principles for installing it in the walls are the same as for between the rafters. You will need a uniform surface to staple the insulation to and to apply a finishing material such as wallboard or paneling.
If your home is already built, your options for increasing the insulation in the walls are limited by the finished materials. It is to this situation I address the use of blown-in cellulose insulation as a way to avoid having to remove the siding or interior walls.
Usually this method will not give you as high an R-value as the same amount of fiberglass insulation. However, it is adequate for beefing up a poor situation in an existing home. Unfortunately, in time the insulation will settle toward the bottom of the wall, leaving uninsulated areas at the top where you need it the most.
Preparation Margin of Error: Exact
Calculate your needs carefully and discuss the possibilities with your dealer. Be sure the type you choose is properly treated with fireproofing. Having a professional do this work may be wise, but it can be done by the novice.
Blown-in cellulose has the advantage of being quick and easy. You won't need to carry a lot of tools and materials with you.
You can blow up to 100 feet away from where the machine is positioned. One person can load the machine in another part of the house or outside while another works in the area to be insulated. This eliminates the discomfort of cramped working quarters when insulating in tight places.