Patent ID: 9725907
Date: 2017-08-08
CPC Classifications: B32B,E04D,Y10T

Claim:
1. A layer of a roofing shingle having an upper surface and an under surface, the layer comprising: a fibrous substrate; an asphalt coating on the fibrous substrate; granules disposed on the asphalt coating; and expandable fire retardant material disposed directly on the upper surface of said layer as a particulate material, wherein said expandable fire retardant material has an average bulk density ranging from 1 to 3 g/cm wherein the expandable fire retardant material is a plurality of particles having an average particle size ranging from 50 to 1000 microns; wherein said expandable fire retardant material is present in said layer in an amount ranging from 0.01 to 1.0 lb/square; and further wherein the expandable fire retardant material is disposed only in an area within two inches of a sealant section.