ABSTRACT
Sealants such as caulk or mastic are used for sealing. Insulation is categorized as either mineral or organic based. Mastic is critical for appropriately sealing duct leaks and joints as well as other cracks in air barrier materials. The mineral-based insulations are perlite, vermiculite, fiberglass and rock wool. Of these, perlite and vermiculite insulations are typically no longer installed in homes. They typically look like popcorn because they form little pellets when they expand by being heated. Fiberglass batts are not correctly installed, there can be significant voids and other weaknesses in the insulation. Often fiberglass batts are compressed into rolls or shrink-wrapped piles so they take up less space in transportation, etc. Blown-in insulation can also be made of fiberglass or rock wool. With the blower machines, a bale of insulation is thrown into an agitator that breaks the insulation into smaller pieces so it can blow through the tube lines.
