Myth #10: Cellulose is good insulation.
Truth: Cellulose is good insulation, BUT only if it is applied correctly. For the past 50 years we have blown cellulose into wall cavities of older homes. The problem was we blew it in “fluffy”, which worked good for a year or two till it settled to the bottom leaving the upper wall uninsulated again. Most insulators (be sure yours’ does) now apply cellulose “dense packed” with compression of 3.5 lbs. per cubic foot and the finished feel of a firm mattress. This will not settle over time and is also a very good infiltration barrier. Cellulose in attics is still applied fluffy but soon settles to become dense.
Cellulose is a recycled product and treated to make it fireproof and mold resistant. With the demise of many newspapers, it is unclear how much longer cellulose will be a “recycled” product.