Since early in its involvement with the roofing industry, the
spray polyurethane foam (SPF) industry has been active within the
U.S. standards community. The current ASTM International standard,
ASTM C1029, "Standard Specification for Spray-Applied Rigid
Cellular Polyurethane Thermal Insulation," covers the types and
physical properties of SPF intended for use as thermal insulation.
SPF materials categorized within ASTM C1029 are used for multiple
types of SPF products, including roofing materials, wall insulation
and storage-tanker insulation.
The standard's physical properties are based on foams using
chlorofluorocarbon (CFC-11) as a blowing agent. These foams were
phased out in 1993. The current blowing agent is
hydrochlorofluorocarbon (HCFC-141b), which will be phased out Jan.
1, 2003. A new blowing agent will be used for the next generation
of SPF-based roof systems.
However, the SPF currently used in roofing applications does not
meet ASTM C1029 requirements. The SPF industry is taking a
two-pronged approach to ensure current SPF-based roof system
materials are within the parameters of ASTM specifications by
revising the minimum properties within ASTM C1029 and developing a
material standard for SPF specifically used for roof systems.
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