What is the typical aggregate size used in a flood coat?

The typical aggregate size used in a flood coat of a built-up roofing (BUR) system is specified as including sizes such as 6, 67, and 7. These sizes refer to the nominal aggregate dimensions measured in a specific grading system, which ensures that the materials used for the flood coat provide adequate coverage and functionality.

Using these particular sizes allows for a consistent application that helps to optimize the roof's durability, promote effective drainage, and ensure proper adhesion to the underlying layers of the roofing system. These aggregates provide a good balance between stability and coverage, thus improving the overall performance of the roofing system.

In contrast, options that suggest sizes less than 3mm or those in the range of 1mm and 2mm are not typically utilized because smaller aggregates can lead to a less effective flood coat, potentially compromising its protective qualities. Similarly, sizes approaching 10mm would be too large for effective embedding in the flood coat, which could hinder the intended function of securing the aggregate layer and protecting the underlying roofing system.