ASTM D 4977: Standard Test Method for Granule Adhesion to Mineral Surfaced Roofing by Abrasion.
The test involves applying a controlled amount of force to the surface of the roof shingle to which the granules are adhered. The force is applied using a brush with bristles. The adhesion is assessed by weighing the amount of granules that are displaced and become loose as a result of the abrasion test.
In the video above, the Cericade Roof Fortification System outperforms the new shingle. Despite the age of the 20 and 48 year old shingles fortified with Cericade, they dramatically outperformed the new shingles and had significantly less granule loss.
Granules detaching leads to a number of roof problems that can be costly to repair. Granules protect underlying roofing material from the elements. If the granules detach, this exposes the underlying materials, which can cause the roof to have a much shorter lifespan.