Here are the main types of insulation being used in America today, along with some of the problems and properties associated with them, according to industry and government experts:
FIBERGLASS. The best known and most widely used, it comes in rolls that can be cut into pads of "batts" and also in a loose fill form that can be blown into place with machines. It is mainly used in attics.
Like glass, fiberglass is spun out of sanc and is quite fire resistant, although sometimes there is paper along one side of the rolls that burns readily.
There have been fears that fiberglass insulation may be cancer-causing and federal authorities are studying his question. No determination has yet been made.
ROCKWOOL. This is the same family as fiberglass: an inorganic mineral wool spun out of slag rock. It has a somewhat higher resistanc to heat loss per unit of insulation quantity, than figerglass.
CELLULOSE. This is the wood fibrious material-usually newsprint ground up fine and chemically treated to make it fireproof and noncorrosive.
Newsprint itself contains chemicals than can corrode pipes, wires and other metal fixtures.
On Sept. 8 this year the federal government instituted standards to insure the fireproof and noncorrosive qualities of cellulose. It comes in loose fill form to be blown into place, usually in attics. Its resistance to heat loss is generally higher than both fiberglass and rockwool.
UREA FORMALDEHYDE FOAM. This chemical insulation material, made of urea and formaldehyde, is pumped in wet form into walls where it dries into hard form and insulates.
It is light-sensitive and tends to shrink and deteriorate into powder when struck by light or when wet - the reason it is used in walls and not attics where light can strike it.
This material has gained the nick-name "shrink and stink" according to Harry ohen of the U.S. onsumer Products Safety ommission.
"In a very small percentage of cases where it is installed things go wrong due to the material or the inadequacy of installation," said ohen. He said gas may be released from it after installation. "It may be a mirror irritation or can really make you sick. We are concerned about this. we are investigating it."