Green Options for Attic Insulation

Fiberglass

• Standard fiberglass insulation contains formaldehyde, which off-gases into the attic space and can pose health concerns. Fortunately, formaldehyde-free fiberglass products are available. Another concern with fiberglass insulation is that it is irritating to the skin. Installers must wear protective gear. Often attic spaces remain unfinished, with fiberglass insulation exposed, so care must be taken not to touch the insulation material when accessing the attic.

Mineral Fiber or Mineral Wool

• Mineral wool can be either rock wool, made from natural minerals such as basalt or diabase, or slag wool, made from molten metal. A benefit of this material is that it contains 75 percent post-industrial recycled content, on average. Mineral fibers come in three insulation forms: batt, loose fill and rigid insulation, all of which are options for attic spaces. Mineral insulation does not off-gas formaldehyde, but batt and loose-fill types may be irritating to the skin. Rigid mineral fiber insulation is a green alternative to polystyrene and polysocyanurate, which use CFCs and HCFCs in their production.

Cellulose

• Cellulose insulation is made with recycled paper, is non-toxic and it does not irritate the skin as fiberglass and mineral fiber insulation can. Loose-fill cellulose fiber insulation works well in unfinished attic spaces because it resists air movement better than traditional fiberglass and mineral fibers. Cellulose is also available in wet-spray form, a good option for attic floors because it also provides an air barrier and leaves minimal cracks and gaps in insulation. Wet-spray cellulose is approximately 80 percent recycled paper.

Denim

• Denim or cotton insulation is made of recycled materials, mainly post-consumer recycled waste such as old blue jeans. In attics, this insulation installs like standard batt insulation, but unlike fiberglass and mineral wool, the installer does not need to wear additional protective gear because it does not off-gas formaldehyde or other VOCs, does not irritate skin and poses no other health risks. Denim insulation meets fire resistance standards, resists mold and mildew and provides acoustic insulation as well.