As a recycled paper product cellulose is prone to absorb moisture that can cause wood rot and mould.
Blown in fiberglass vs cellulose attic.
Rather than trying to meticulously lay fiberglass insulation over the attic homeowners and builders can simply blow cellulose insulation throughout the attic.
Making cellulose a better choice for homes in northern climates.
You can get to the same place with either material.
This allows the insulation to get into the small pockets and crevices that fiberglass wouldn t be able to.
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 has a higher r value and even does not lose the value in the extreme cold were fiberglass may.
Fiberglass blown in involves using a machine to pump 2 the loose insulation into the wall cavities.
Thus creating a more energy efficient home.
According to research done at the oak ridge national lab fiberglass loses up to 50 of its r value in very cold conditions.
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.
Or 7 inches of cellulose.
Advantages and disadvantages of fiberglass advantages.
Cellulose insulation is always blown in.
At 3 5 per inch of material the r value of blown in cellulose is 23 better per inch than fiberglass batts.
Cellulose produces much less static than fiberglass.
Loose fill or blown cellulose insulation is manufactured primarily from recycled newspapers a very benign product so it poses virtually no ongoing health risk.
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.
Cellulose resists blowing when installed fiberglass tends to blow around stick to the attic ceiling and drift.
This is slightly more difficult but provides better installation.
It can still be done diy by renting a machine.
More consistent pricing from cellulose manufacturers than fiberglass.
Dry blown cellulose will characteristically settle and sag in place reducing its r value.
By nature the cells inside the cellulose insulation have their own insulating power.
Which means cellulose insulation can be compressed into a space and offer additional r value.
Wet blown cellulose is also subject to similar contamination too.