Disadvantages
Cellulose has a few disadvantages. As compared to other insulation options, the R-value of 3.6 to 3.8 per inch is good but not the best. Cost per R-value is good. Spray foam has many of the same benefits as wet-spray cellulose (such as sealing the cavity), while having advantages in R-value and rigidity and air sealing. Many spray foams utilize an environmentally harmful blowing agent, such as Enovate HFC, cellulose does not.
Read more about this topic: Cellulose Insulation