Properly insulating a structure using Johns Manville building insulation helps preserve our environment by reducing energy consumption for heating and cooling, reducing the pollution resulting from fuel burning, reducing the emission of hazardous air pollutants during manufacturing and reducing waste through the utilization of recycled materials. Coverage is 45.4 Sq. Ft. at R40 and is lightweight, thermal and acoustical fiberglass insulation. Premium blown-in fibreglass insulation which can be used to cover attics and hard-to-reach areas within attics, like corners, edges and around framing. When it's applied to the recommended thickness and specifications, you can be assured that your home is energy-efficient, with minimal heat loss. It won't settle, decay or provide food for animals or microbe and is effective for the life of your home and can be installed up to R-70 over 1/2-in ceiling drywall without exceeding ceiling weight limits. ASTM C764, type I, standard specification for mineral fibre loose-fill thermal insulation, ASTM E84 flame spread 25 or less, smoke developed 50 or less, ASTM E136 non-combustible, ASTM C764 non-corrosive.