Mold on insulation often appears as black, brown, or greenish discoloration and is accompanied by a musty, dank odor.
Attic insulation levels are measured by R-Value, which indicates resistance to heat flow. Most attics should be insulated to R-38, or about 10 to 14 inches, depending on the insulation type.
Double bubble insulation consists of two layers of polyethylene bubbles between two metalized coatings, effectively preventing frost and condensation in various structures.