Blown In Fiberglass Vs Cellulose 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.

Blown in fiberglass vs cellulose attic.

You can get to the same place with either material. In contrast to fiberglass insulation cellulose insulation does not trap air in between it s fibers to control heat. According to research done at the oak ridge national lab fiberglass loses up to 50 of its r value in very cold conditions. Cellulose is easier to keep out of bird blocks and air conditioner condensate pans.

Which means cellulose insulation can be compressed into a space and offer additional r value. One aspect to consider is air infiltration and in that cellulose is the top choice due to its ability to form a dense mat that allows the air within the insulation to keep moving. Or 7 inches of cellulose. Fiberglass blown in involves using a machine to pump 2 the loose insulation into the wall cavities.

Cellulose resists blowing when installed fiberglass tends to blow around stick to the attic ceiling and drift. Wet blown cellulose is also subject to similar contamination too. It can still be done diy by renting a machine. By nature the cells inside the cellulose insulation have their own insulating power.

As a recycled paper product cellulose is prone to absorb moisture that can cause wood rot and mould. Rather than trying to meticulously lay fiberglass insulation over the attic homeowners and builders can simply blow cellulose insulation throughout the attic. This allows the insulation to get into the small pockets and crevices that fiberglass wouldn t be able to. At 3 5 per inch of material the r value of blown in cellulose is 23 better per inch than fiberglass batts.

Blown fiberglass on the other hand is made up of very fine strands of glass and these tiny fibers are a carcinogen that can easily be inhaled into your lungs. Thus creating a more energy efficient home. Loose fill or blown cellulose insulation is manufactured primarily from recycled newspapers a very benign product so it poses virtually no ongoing health risk. Cellulose has a higher r value and even does not lose the value in the extreme cold were fiberglass may.

Cellulose insulation is always blown in. This makes it slightly more difficult than fiberglass batts but comparable to blown in cellulose. Dry blown cellulose will characteristically settle and sag in place reducing its r value. Cellulose produces much less static than fiberglass.

This is slightly more difficult but provides better installation.