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.
Cellulose or fiberglass in attic.
Pros and cons of loose fill fiberglass attic insulation.
This is called wind washing.
Air moving through a vented attic deposits dirt and dust into fiberglass batts.
Rather than trying to meticulously lay fiberglass insulation over the attic homeowners and builders can simply blow cellulose insulation throughout the attic.
Cellulose is more difficult to cheat than fiberglass.
Unless you opt for spray foam then the insulation choices normally come down to cellulose and fibreglass.
When walls are already finished injecting loose fill cellulose insulation is one of the few ways of adding.
This keeps the air from moving within the insulation and from penetrations between the air conditioned space and the attic.
Like cellulose you need a big machine to blow it in.
As the temperature difference between the living space and attic increases the r value of blown fiberglass diminishes.
Loose fill cellulose insulation can settle around and conform to most of the obstructions found in walls and attics.
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.
Cellulose forms a dense continuous mat of insulation in your attic.
You can t simply buy it in bags and spread it around yourself.
When there are fiberglass batts in your attic the cellulose will not draft block the top plates.
Blown cellulose is typically the preferred choice of insulation for attics.
The two main least expensive and most commonly used residential insulation materials is cellulose and fibreglass.
Loose fill fiberglass seems to dominate attic insulation in new construction homes and has an r value of approximately 2 5 per inch.
Or 7 inches of cellulose.
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.
Loose fill blown fiberglass insulation has another slight problem.
Compared to fiberglass cellulose is a superb air blocker.
Cellulose has 38 better air infiltration 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.