What Is Loose-Fill Insulation?I’ve talked before about the value of insulation, but it’s also important to know about the different types of insulation. Loose-fill insulation, sometimes called blown-in insulation, is a type of insulation that is specially-suited to fill in the nooks and crannies of new construction. Compared to blanket batts and rolls, which come stock on most houses, the nature of loose-fill means it will do a better job of limiting gaps that inevitably decrease your home’s energy efficiency by allowing too much air seepage. Your house is usually a lot like your neighbors’ when it’s first built, but once you decide to undergo any renovations, it’s possible that you’ll be changing the shape of your house. If so, your wall and ceiling cavities might not be so uniform anymore—especially if you pick a style that’s particularly modern or innovative. That’s why it’s really beneficial to pick out a type of insulation that will conform to the voids around your new studs or joist bays, as well as cavities that include electrical boxes, wiring, plumbing vents, and blocking. Standard batt insulation just doesn’t work as well when it comes to filling in these odd crevices and cavities—it won’t do a complete job sealing in air, which should be the ultimate goal of your new insulation. It’s an easy choice to decide to go with loose-fill over batt insulation, but what’s a bit harder is deciding whether you want your loose-fill insulation to be made of cellulose or fiberglass.
Cellulose Versus Fiberglass When Choosing Loose-FillOnce you’ve decided you want to go with loose-fill insulation, the next question is whether you want that insulation to be made from cellulose or fiberglass:
- Cellulose insulation: Cellulose is the top choice of most environmentally-friendly green builders because it’s made from ground-up newspaper, with most brands using between 75 and 80 percent recycled material. Cellulose is also inexpensive, and it performs a bit better under most circumstances. The efficiency of insulation is rated with an R-value, which is the measure of insulation’s ability to prevent heat from passing through it. Cellulose is denser than fiberglass insulation, and that gives it a slightly higher R-value, about 3.7 compared to the fiberglass rating of 3.5.
- Fiberglass insulation: Fiberglass is similar to cellulose when it comes to loose-fill because they can both fit and fill irregular spaces that batt insulation can’t. However, fiberglass insulation isn’t as environmentally-friendly, and it’s believed to carry a minor health risk, although that hasn’t been officially substantiated. Still, fiberglass, which is made of chopped glass insulation fibers, is best kept to spaces where those fibers have no chance of entering occupied space—or an HVAC system.