Eco-Friendly Insulation Options

Feb 20, 2010 | Energy Efficiency

Snapshot | Some options | How to find it

Think beyond the pink: Ecologically conscious homeowners can choose from a growing array of low-toxic, low-allergenic, and low-impact insulating materials.

Insulation can be eco-friendly for many reasons: it uses recycled content, it has smaller environmental impact during manufacturing, it is healthier to install, it is healthier to live with, and/or it is biodegradable or recyclable after use.

Eco-friendly insulating materials such as cellulose and cloth insulation often cost a bit more than fiberglass. Fortunately, insulating your attic qualifies for rebates by most Bay Area utilities, helping to offset any price premium. Check out federal incentives on energy-efficient products

New, environmentally low-impact and nontoxic insulating materials are popping up on the market. Here are some choices:

Fiberglass batts: A surprise to many, fiberglass insulation is relatively natural and low toxic. It's made from silica sand (just like glass) and contains much as 30% recycled glass. It's relatively inexpensive, resistant to mold, and inedible to insects and rodents.

Here's the bad news: The tiny glass fibers can be a hazard to skin and eyes. If inhaled, they can lead to respiratory problems, some linked to cancer. Also, some batts contain formaldehyde-based binders that might emit fumes for years, possibly causing other illnesses.

And here are the solutions to the bad news: To address the tiny fibers problem, major manufacturers now offer sealed batts. Perforated polyethylene sheeting controls loose particles and doubles as a vapor barrier.

To solve the formaldehyde problem, at least one manufacturer now uses a nontoxic acrylic binder; another uses a product that binds fibers together without chemicals.

If you're still concerned about fiberglass, consider other options that use recycled or organic materials.

Mineral wool or rock wool: Mineral wool or rock wool insulation is similar to fiberglass, but the fibers are made of spun minerals and metals. Although more expensive than fiberglass, mineral wool has fire-retardant properties and is moisture-resistant, maintaining its insulating properties when wet.

While handling both fiberglass and mineral wool, you should always wear a dust mask and gloves to minimize breathing and touching the fibers.

Rockwool insulation

Cellulose: Typically made from recycled newspaper, cellulose insulation can provide more insulation per inch than fiberglass. Cellulose is available as wet blow-in or dry loose-fill insulation, usually in the form of fluffy clumps of fibers and flakes. To make this paper-based insulation resistant to pest and fire, cellulose insulation might be treated with boric acid and mixed with clay or silicates, both of which are harmless healthwise. However, it can also contain inks and solvents that are the result of using recycled newspaper.

Although it has not been shown to cause a health risk, blowing in cellulose is dusty work, so you should wear a mask around freshly installed loose cellulose. Once installed, cellulose sometimes settles, so an installer might top it off after initial installation. It also loses efficiency if it gets wet. If allowed to remain damp, cellulose can harbor mold.

Wet blow-in cellulose is becoming more popular and it does not the have dust and airborne-particle issues of dry cellulose. One manufacturer claims it has been installed in 1 million homes in the United Kingdom alone.

Insulation made of recycled denim scraps

Cotton and other natural cloth: Cotton could be the safest insulating material for both the installer and home occupants. Available in batts or loose-fill, it costs about twice as much as fiberglass. Some cotton insulation contains 85% post-industrial fibers, such as denim collected from blue-jeans manufacturers. Virgin cotton is one of the more chemical, water, and fertilizer intense crops in the U.S., but manufacturing insulation using cotton fabric scraps creates a lasting use for materials that might otherwise be discarded. Cotton insulation has lower dust content and no fibers that can be irritants to skin and lungs. Cloth is also free of volatile organic compounds (VOCs).

Hemp insulation uses mostly hemp fiber, with a little added polyester fiber for reinforcing. A manufacturer claims hemp is naturally resistant to moths and beetles, so an extra chemical application is avoided.

Soy and other biological foams: Spray-in insulation foams made from soybeans and other organic polymers are recent arrivals to the insulation market. They offer all the benefits of conventional spray foam without formaldehyde or other environmental hazards. Manufacturers claim they are resistant to mold and mildew.

• If insulating your home yourself, find eco-friendly insulation options at your home supply or building supplies store. In some areas, you might have to special order it.

• Ask your insulation contractor about eco-friendly insulation options. If your contractor doesn't have an option you like, specify the specific material you want. Call WattzOn to find qualified insulation contractors in your area.