Is My Attic Insulation Is Cellulose Or Fiberglass

Pros and cons of loose fill fiberglass attic insulation.

Is my attic insulation is cellulose or fiberglass.

When walls are already finished injecting loose fill cellulose insulation is one of the few ways of adding. Loose fill fiberglass seems to dominate attic insulation in new construction homes and has an r value of approximately 2 5 per inch. Cellulose has 38 better air infiltration than fiberglass. This keeps the air from moving within the insulation and from penetrations between the air conditioned space and the attic.

Assuming your current attic insulation is made from fiberglass and has a value of r 13 you d have to add roughly 10 inches of additional fiberglass to hit r 38. Cellulose is more difficult to cheat than fiberglass. Loose fill cellulose is relatively inexpensive yet still has an r value of about 3 5 per inch of thickness compared to fiberglass r value between r3 to r4 per inch. This problem has been successfully solved by installing fiberglass batt insulation over the top of loose fill or blown insulation.

The trapped air molecules in the insulation are pulled up through the insulation into the colder attic air. You can get to the same place with either material. Lighter in weight than cellulose or mineral wool but it settles more than those materials so you ve got to put in a thicker layer to get the protection you need. Cellulose forms a dense continuous mat of insulation in your attic.

Loose fill cellulose insulation can settle around and conform to most of the obstructions found in walls and attics. The bottom line is that cellulose can burn but fiberglass will not support combustion.