As any homeowner with fiberglass insulation in their attic may know, the itchy material is a perfect place for squirrels, mice and other small animals to burrow and make a family of their own.
Fiberglass insulation stays in place when burrowed into, creating a cozy home for a rodent to nest in and a perfect spot for a mother mouse to have little children to annoy homeowners. Insects can also make themselves at home in attics or inside walls, giving them another place to nest before unleashing their children upon your home.
Cellulose insulation serves a dual purpose
Killing some of the pests, or at least giving them the motivation to move somewhere else, can be done through a product that you normally wouldn't think could provide such a dual purpose: cellulose insulation. Often made of recycled newspaper, the loose insulation is treated with boric acid partly as a flame retardant and resistance to fungus. If enough boric acid is added, the insulation can serve multiple purposes, acting as a pesticide along with keeping your home warmer and more energy efficient.
"People hear the word 'pesticide' and they immediately recoil," says Brandon Ansley, director of business development for T•A•P Insulation. But they shouldn't recoil, Ansley says, because the toxicity to humans is low and, when used properly, pesticides are quite beneficial.
T•A•P Insulation is a "green" product made of recycled paper. It's blown in on top of existing insulation, and along with controlling pests, it offers "superior thermal and sound-deadening properties." Introduced to the insulation market in 2001, T•A•P Insulation is registered with the Environmental Protection Agency and in all 50 states.
How it works
T•A•P Insulation kills self-grooming insects that get into your insulation when the insects lick their arms and clean their bodies, with the poison attaching to their bodies, Ansley says. These crawling arthropods include ants, termites, cockroaches, crickets, sow bugs, centipedes, millipedes, and booklice.
The insulation has a low toxicity to mammals such as mice that filter out the poison through their livers, Ansley says. But because the cellulose insulation is loose and falls in on itself, rodents don't like it and will often leave because they prefer areas where they can burrow in order to nest.
Of all insulations, spray foam has the highest R-value, which measures an insulation's resistance to heat flow. The higher the R-value, the more effective the insulation. Cellulose insulation has the next best R-value, followed by fiberglass, Ansley says.
What it costs
T•A•P Insulation costs 15 percent to 20 percent more than standard cellulose, partly because a pesticide installation license is needed by an installer, he says. Cellulose insulation, without the added pesticide, is about the same price as fiberglass insulation, says Mike Rogers, senior vice president of GreenHomes America, a company that provides home energy assessments and upgrades, and sells cellulose insulation treated with borates as a flame retardant. For us, killing bugs is a secondary purpose, Rogers says, and one that the company doesn't promote because it would require EPA approval.
Since most homes have about half the amount of insulation that they should have to stay warm in the winter, according to Ansley, adding cellulose insulation on top of existing insulation doesn't present any issues to your existing insulation, and will only serve to keep your home warmer. Insulation that heats your home, gets rid of pests and works as a sound buffer is like getting three benefits for the price of one.
Aaron Crowe is a freelance writer in San Francisco. He has worked as a writer and editor for websites and newspapers, most recently covering personal finance for WalletPop.com. He has also written for Bankrate, AARP and was one of the initial writers at AOL Housing, covering the housing and rental markets.