Blown-in loose fill is one of the easiest forms of insulation to install. Commonly made of cellulose, glass fiber, mineral wool, perlite or vermiculite, it can be blown into areas needing insulation. Equipment for blowing insulation into walls or attics can be rented, or contractors with their own equipment can be hired to do the job.

To ensure getting the maximum R-value from the insulating material, watch the density setting used. Properly blown loose fill generally has a higher insulating value per inch than poured loose fill because of the loft added by blowing. As with all insulation types, vapor barriers are often needed.

A new and increasingly popular form of this insulation involves blowing glass or wool fibers mixed with an adhesive into building cavities. The resulting installation cures in a few days, is resistant to settling, and provides effective sealing of the cavities.