Is My Attic Insulation Is Cellulose Or Fiberglass

Cellulose has 38 better air infiltration than fiberglass.

Is my attic insulation is cellulose or fiberglass.

The trapped air molecules in the insulation are pulled up through the insulation into the colder attic air. Loose fill cellulose insulation can settle around and conform to most of the obstructions found in walls and attics. You can get to the same place with either material. Recycled glass or sand that s melted and spun into fibers.

Loose fill fiberglass seems to dominate attic insulation in new construction homes and has an r value of approximately 2 5 per inch. If you check with the cellulose insulation manufacturers association they ll assure you that cellulose is definitely your best choice for insulation. 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.

Pros and cons of loose fill fiberglass attic insulation. 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 forms a dense continuous mat of insulation in your attic. The bottom line is that cellulose can burn but fiberglass will not support combustion.

Or 7 inches of cellulose. This keeps the air from moving within the insulation and from penetrations between the air conditioned space and the attic.