Over the last few weeks, we’ve been talking about weatherizing the lived-in areas of your home. Today, the focus of our energy series will be on a part of our homes that we often neglect, from spring cleaning to installing insulation: the attic. You can improve the energy efficiency of your home a great deal by insulating this one area. Since heat rises, a ton of heat is lost in your home through your attic in the winter. Slowing that process by adding properly installed insulation to your attic is one of your best defenses against cold temperatures and energy waste.

Imagine the exterior of your home as an envelope for the interior. This helpful metaphor comes from US Department of Energy consultant Matt Golden, who encourages homeowners to start with the attic when sealing that envelope. According to Golden, “the most important step is filling any penetrations in the attic floor, such as around pipes, chimneys, wiring, and recessed light fixtures in the ceiling below… if you insulate only one thing, it should be the attic floor, since heat rises. You want at least 10 inches of insulation up there.” By first sealing any air leaks and then bringing insulating power to the attic floor, you can drastically slow down the process of heat rising up and out of your home.

Types of Attic insulation

In addition to insulating the attic floor, blown-in (loose fill) insulation can be installed in the attic and help seal the envelope even more securely. There are three different types of insulation you’ll find: fiberglass, cellulose, and mineral wool. Each of these is made up of a recycled material, and each offers excellent insulation when properly installed. Cellulose is made from the pulp of recycled newspaper and boxes. Fiberglass utilizes 20-30 percent recycled glass, which is heated at high temperatures in order to spin it into fibers. And mineral wool, sometimes called rock wool, is made of the recycled byproduct of molten metal–it’s manufactured in a manner similar to fiberglass.

Each type of blown-in insulation presents the consumer with an excellent opportunity to embrace an environmentally-friendly approach to increasing a home’s energy efficiency. There are some slight differences, however. While cellulose is often the most cost-effective material, HGTV notes that “Cellulose loses 20% of its R-value, so you should add 20 percent more in an attic during installation.” On the other hand, “the settling percentage of fiberglass and mineral wool is minimal and doesn’t affect thermal performance.” So keep this in mind when weighing the costs associated with each option.

Blown-In Insulation is a Smart Choice for Attics

Blown-in insulation is a great solution because most attics, by their nature, have small crevices, areas that are difficult to access, and oddly-shaped or sloped spaces. Blown-in insulation reaches these places easily and can also be installed within attic walls. Because the efficacy of any insulating material depends so much on proper installation, we recommend calling a professional if you’re thinking about installing this kind of energy-saving upgrade in your home.