Codes for building, fire prevention and electrical wiring must be followed. For example, keep insulation at least 3 inches away from any heat- producing objects in the attic, such as bath fans or recessed light fixtures. Making insulation reach out to the ends of the attic is critical in eliminating heat loss, Arick said. Using baffles over the vent to screen out any attic moisture and mildew also is a must, he said. During winter, an improperly ventilated attic can create ice dams, buildups of ice and water under shingles and sheathing, he said.
Ice dams can lead to damaged ceilings and roof decks.
If planning to install lights or ceiling fans in the attic, homeowners are advised to do so before adding insulation. Once you have a good insulation job, it is absolutely to your benefit not to go up there,'' Arick said. On lower floors, exterior walls of older homes can be insulated without tearing out drywall by drilling holes from the inside and blowing in chips. For more information The Insulation Contractors Association of America, an Alexandria, Va.-based nonprofit organization representing professional residential and commercial insulation contractors, offers advice to consumers from its Web site, insulate.org. The Federal Trade Commission regulates the insulation industry to ensure that consumers make informed decisions.