4.1 One of the functions of a roofing aggregate is to shield the roofing membrane from sunlight that may be destructive to the roofing membrane. This test method measures the quantity of gravel needed to exclude light under arbitrary laboratory conditions. This test method need not be performed if the roofing membrane is not affected by light exposure.

1.1 This test method measures the quantity of aggregate needed to provide an opaque layer under laboratory conditions. Aggregate size Numbers 1 through 8, as listed in Classification D448, may be tested.

1.2 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.

1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.