Determining these performance characteristics of vegetative (green) roof systems provides information to facilitate the assessment of related engineering aspects of the facility. Such aspects may include structural design requirements, mechanical engineering and thermal design requirements, and fire and life safety requirements.

Accurate information about the water and media holding capacity of geocomposite drain layers is essential to predict dead load for vegetative (green) roof systems.

Determining these performance characteristics of vegetative (green) roof systems provides information to facilitate assessment of the performance of one vegetative (green) roof system relative to one another.

Water capture is also useful in assessing irrigation requirements for vegetative (green) roof designs.

Information about the unit media retention volume is required to predict the quantity of material that will be required to construct a vegetative (green) roof with a specified total thickness.

1.1 This test method covers the determination of the water and media retention of synthetic drains layers used in vegetative (green) roof systems.

1.2 This test method is applicable to geocomposite drain layers that retain water and media in cup-like receptacles on their upper surface. Examples include shaped plastic membranes and closed-cell plastic foam boards

1.3 This test method does not apply to products manufactured from water-absorptive materials.

1.4 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.

1.5 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 and health practices and to determine the applicability of regulatory limitations prior to use.