Cellulose insulation has been exposed to a broad range of construction, environmental, and various code requirements that have called for a more elaborate definition of physical properties. These requirements have been identified and met in the following federal regulations, federal procurement specifications, and industry standards.4
Cellulose insulation intended for spray-on application in new walls is classified as a type II material under American Society for Testing and Materials (ASTM) Standard C1149. These materials normally contain adhesive to produce the cohesion necessary to make the insulation self-supporting. The adhesive may be
Figure 9.2 Stud scrubber. (Greenstone)
liquid added during the spraying process, or it may be dry adhesive contained in the insulation during the manufacturing process and activated by moisture during application.
16 CFR Part 1209, “Consumer Products Safety Commission Interim Safety Standard for Cellulose Insulation,” also referred to as the CPSC Safety Standard. This is the Consumer Products Safety Commission (CPSC) safety standard that covers four product attributes: settled density, corrosiveness, critical radiant
flux (a measure of surface burning), and smoldering combustion. It is illegal to market cellulose insulation that does not conform with this section of the Code of Federal Regulations.
16 CFR Part 460, “FTC Trade Regulation Rule, Labeling and Advertising of Home Insulation,” also known as the FTC R-Value Rule.
ASTM C167, “Test Methods for Thickness and Density of Blanket or Batt Thermal Insulations.”
ASTM C168, “Terminology of Terms Relating to Thermal Insulating Materials.”
ASTM C739, “Specification for Cellulosic Fiber (Wood Based) Loose Fill Thermal Insulation.” This is the industry standard for loose-fill cellulose insulation. It covers all the factors of the CPSC regulation and five additional characteristics: R-value, starch content, moisture absorption, odor, and resistance to fungus growth.
ASTM C755, “Recommended Practice for Selection of Vapor Barriers for Thermal Insulation.”
ASTM CIO 15, “Practice for Installation of Cellulosic and Mineral Fiber Loose Fill Thermal Insulation.”
ASTM C1149, “Standard Specification for Self-Supported Spray Applied Cellulosic Thermal/Acoustical Insulation.”
ASTM C1338, “Test Method for Determining Fungi Resistance of Insulation Materials and Facings.”11
ASTM E 970-89, “Test Method for Critical Radiant Flux of Exposed Attic Floor Insulation Using Radiant Heat Energy Source.”
Cellulose insulation is formulated and labeled as self-supporting, spray-applied material. Spray-applied cellulose installed in closed walls and in attics is approved for use in every code jurisdiction on the basis of conformance with the CPSC safety standard for loose – fill cellulose.
Although many of the tests described in ASTM C1149 differ from those in C739 and the similar CPSC 16 CFR Part 1209 procedures, manufacturers are justified in claiming CPSC compliance on the basis of the C1149 methodology because the tests described in C1149 are “reasonable test procedures.”4 ASTM C1149 covers 10 material attributes: density, thermal resistance, surface burning characteristics, adhesive/cohesive strength, smoldering combustion, fungi resistance, corrosion, moisture vapor absorption, odor, and flame resistance permanency. Material installed using liquid adhesive (type I) also has substrate deflection and air erosion characteristic requirements. Obviously, under C1149, spray-applied material is tested in the sprayed state. The requirements for type III material defined by ASTM C1149 cover some attributes of stabilized cellulose. Specifiers may wish to require conformance with this standard.4