A sheet material made of randomly oriented glass fibers bound together with a resinous binder. It serves as the structural core for built-up roofing plies, modified bitumen membranes, and asphalt shingles. The fiberglass provides high tensile strength, resists moisture rot, and holds the waterproofing asphalt in place.
Heard on the job
Roll out three plies of glass felt and mop them in solid.
Also heard as
- fiberglass felt
- glass mat