Fiber Glass

Fiber glass is an inorganic material, and is therefore noncombustible. This does not mean fiber glass provides greater fire safety. The National Fire Academy notes: "It is critical to recall that noncombustible does not mean 'safe.' It certainly does not mean 'fireproof.' The concept of fire-resistance goes beyond that of noncombustibility. It refers to the capacity of a material or construction to withstand fire or give protection from it." Fiber glass does not measure up to either standard. The open structure of fiber glass makes abundant amounts of oxygen available to wood and other combustible materials in ceilings and walls. Assemblies insulated with fiber glass are much less fire resistant than walls and ceilings insulated with cellulose, as studies by the National Research Council Canada proved. In a paper presented at an ASTM symposium a prominent fire protection expert noted that: "Standard fiber glass has an operating temperature of 350o F. Temperatures above that tend to make it shrink. Before fiber glass loses its physical characteristics, it can contribute to the fire. Generally speaking fiber glass does not provide adequate protection in a fire. A panel composed partly of fiber glass can lose its physical properties within 10  minutes, depending on the extent of the fire." Facings of fiber glass batts are usually combustible and may accelerate the progress of a fire, especially if batts are inset stapled, a practice that creates miniature "chimneys" lined with paper or petrochemicals with absolutely no fire retardants. These fiber glass deficiencies account for the opinion of a contractor who is also a fire fighter with 19 years experience who said: "Being in the construction business and in the fire service there is no one who could convince me that fiber glass insulation is safer than cellulose in an attic.