Cellulose Or Fiberglass In Attic

Unless you opt for spray foam then the insulation choices normally come down to cellulose and fibreglass.

Cellulose or fiberglass in attic. You can t simply buy it in bags and spread it around yourself. As the temperature difference between the living space and attic increases the r value of blown fiberglass diminishes. Rather than trying to meticulously lay fiberglass insulation over the attic homeowners and builders can simply blow cellulose insulation throughout the attic. Or 7 inches of cellulose.

This is called wind washing. Once it has settled fiberglass has an r value of 2 1 2 7 per inch while cellulose has an r value of approximately 3 0 per inch. Compared to fiberglass cellulose is a superb air blocker. 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. Pros and cons of loose fill fiberglass attic 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. When there are fiberglass batts in your attic the cellulose will not draft block the top plates.

Cellulose has 38 better air infiltration than fiberglass. So what are the advantages and disadvantages of each of these. 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. Like cellulose you need a big machine to blow it in.

The two main least expensive and most commonly used residential insulation materials is cellulose and fibreglass. Blown cellulose is typically the preferred choice of insulation for attics. Cellulose is more difficult to cheat than fiberglass. This keeps the air from moving within the insulation and from penetrations between the air conditioned space and the attic.

You can get to the same place with either material. Air moving through a vented attic deposits dirt and dust into fiberglass batts. It will however fill in all the gaps that fiberglass batts leave along side of your ceiling joists if you see wood its no good and add the to your r factor cellulose is second best with spray 2 part high density spray foam as first in my book. Loose fill fiberglass seems to dominate attic insulation in new construction homes and has an r value of approximately 2 5 per inch.