Which ASTM specification size is NOT one of the sizes for the aggregate in a flood coat?

The correct choice is based on the established ASTM specifications for aggregates used in the flood coat of built-up roofing systems. In the context of these specifications, aggregates are categorized by size, primarily to ensure proper application, adhesion, and performance of the roofing system.

The sizes defined in ASTM standards specifically note the use of Number 6, Number 67, and Number 7 as acceptable aggregate sizes for flood coats. Each of these specified aggregates has particular characteristics that lend themselves to effective performance in roofing applications, such as promoting drainage, providing stability, and enhancing durability.

However, Number 5 is not recognized as a standard size for aggregate in the flood coat according to ASTM specifications. This implies that using aggregates outside of the specified sizes may lead to complications in installation or roofing performance. Therefore, it is essential to adhere to the specified sizes to ensure compliance with industry standards and the overall effectiveness of the roofing system.