Cellulose Insulation for Walls of Existing Homes with Existing Insulation
Cellulose insulation is one of the most energy efficient insulation materials used today.
Insulating an existing home can be a process that is messy, time consuming, and frustrating if you do not know what you are doing. If you want to have your house professionally insulated the right way the first time, you have to use the correct products and methods.
Dense Pack Cellulose
Cellulose insulation is 100% recycled newspaper that is ground up and can be blown into attic and walls for insulation. Borates and sulfides are used as fire retardants for the cellulose and also act as a mold resistant and pest deterrent.
Dense packing is a method used by professional insulation companies in which a 1 ½ inch hole is drilled in between the wall cavities from the exterior of the home and cellulose is pumped through a hose and to a tube that is inserted into the wall. The cellulose fills the cavity and is slowly pulled out to continue packing insulation into the cavity so that no more insulation can be packed into the cavity.
This creates a dense cavity full of insulation, thus the name “dense pack.” In order for the material not to settle, this process needs to be executed so that the maximum amount of material possible is inserted into the cavities without blowing the wall apart. The density of this product in a 2x4 or 2x6 wall is between 3.0 lbs/cubic foot and 3.5 lbs/cubic foot. Cellulose settles at 2.8 lbs/cubic foot, so no settling should occur if the cavities are properly filled.
The R-value of these cavities will be R-13.5 to R-14 for 2x4 wall studs. 2x6 wall cavities will have an R-value of R-21 to R-24. The R value is impressive, but the air sealing quality of cellulose material is what sets it apart from other insulation materials.