foam and metal both lost spring faster than other

foam and metal both lost spring faster than other materials.

Large aluminum sliding windows and window air conditioning units are difficult to weatherstrip, noted Naismith. He advised using foam in the window track and removing window units during colder months.

Insulation R Values

Naismith explained that insulation is rated on the basis of R value or resistance to heat loss. R values are listed on insulation and the higher the number, the better the insulation levels are:

—Ceilings, R26-30 (approximately nine inches)

—Walls, R13 (approximately three and a half inches)

—Supply and return air ducts, R8-13 (three to four inches)

—Floors over unheated areas, Rll-13 (three and a half to four inches)

Naismith suggested nine inches of insulation for attics, adding that at least six inches were needed to achieve any benefit. He noted that in cases where walls were already insulated, but below recommended R levels, it was usually not cost effective to add more.

Insulation comes unbacked or with a vapor barrier and Naismith told the audience that it’s best to add unbacked insulation where there’s already some up. He noted that the vapor barrier should always be placed against the warm side of the structure to prevent either the insulation getting wet and losing its effectiveness or causing structural damage.

He said that fiber glass is generally the most cost effective material to use although blown-in cellulose (ground up newspaper treated with chemicals) is the “up and coming material.”

According to Naismith, ten per cent of the costs of heating a house can be lost through space between the chimney and framing and suggested filling the gap with fiberglass. He said an additional 40 cents out of every dollar spent on heat is lost if ducts are not insulated and advised wrapping fiber glass around ducts and taping it in place.