Fiberglass additives are combustible. Fire Proof Fire resistant, but when ignited, the material will support combustion. The additives that make cellulose fir resistant often dissipate over time, leaving the material readily combustible. Density Ranges 1.4-2.5 lbs. 1.4 -1.9 lbs.
Density is established by each manufacturer's specifications and test data.
To obtain the required insulation value, the specified density and thickness must be installed. Installed Density Subject to over fluffing. Highly subject to over fluffing. Resists over fluffing. When cellulose and fiberglass are installed at less than design density, the R-value per inch is dramatically reduced.