What is the weight of Silent Roof

What is the weight of a Silent Roof installation? The weight of the Silent Roof Material is only 800g per square metre. It is not absorbent so will not retain rain water to add to the loading on a given roof structure.

A close up image of black Silent Roof  Material (SRM) can be seen below. The flat side of SRM faces uppermost which helps to prevent leaf debris and the like collecting on the surface.

Silent Roof Matting Material (SRM) - close up image