- While both cellulose and Fiberglas insulation come as loose-fill materials, only cellulose is available wet or dry for uniform coverage. Fiberglas also comes as batts, pre-cut panels, or roll insulation with or without paper backing for wicking moisture away.
- R-values represent the insulating material's ability to resist heat transfer and loss with higher numbers per inch being the better material. Compared to loose-fill Fiberglas, which only has a rating of 2.2 and Fiberglas batts, which rate 3.25, cellulose insulation offers the greatest insulating properties with a rating of 3.4 per inch.
- Cellulose insulation contains 80-percent recycled post-consumer newspaper. It is biodegradable, while Fiberglas insulation is spun from molten glass and requires a lot of energy to produce.
- Cellulose insulation is blown into wall cavities through a hopper and hose. It is a two-person job, while Fiberglas insulation in batt or roll form is secured into place and needs only one person to complete a project.
Flame, Pest, and Mold
- Manufacturers of cellulose insulation coat the fibers with boron to reduce the risk of fire, repel pests and rodents, and inhibit growth of mold and mildew. Fiberglas is susceptible to ants and mice and burns quickly with intense heat.
- Prices can vary by region, insulating depth and R-value requirements. Cellulose insulation is estimated at just under a dollar per square foot, while blown Fiberglas runs about 40 cents per square foot.