1.1 ,This guide makes recommendations for the selection and application of prefabricated drainage media used in conjunction with waterproofing systems on horizontal and vertical surfaces. Drainage media considered include rigid and semi-rigid insulation boards and rigid materials including plastics. This guide considers drainage media as it relates to the performance of the waterproofing system, so its primary focus is draining water away from the membrane. This guide does not cover in detail other aspects or functions of drainage system performance such as efficiency of soil dewatering. The scope of this guide does not cover other drainage media including gravel and filter fabric systems that can be constructed. The scope of this guide does not cover drainage materials or drainage system designs used for vegetative roof systems. Vegetative roof systems require specialized designs.