Fire-resistant core for a combustible fire-rated panel

Abstract

A fire-resistant core for use in a combustible fire-rated building panel (1), such as a fire door, has a wood product-containing solid structural member (20) with a density of between about 30 and 60 lbs. per cubic foot and a thickness between about {fraction (1/16)} inch and two inches. At least one layer of fire-resistant composite (21) is attached to at least a lateral surface (22) of the structural member (20). The composite has an inorganic, non-woven fibrous web (25) with a thickness of from about 5 to 50 mils. A web binder is substantially uniformly dispersed throughout the web (25). A substantially continuous coating (27) is on at least a lateral surface (28) of the web (25). The coating is of particulate vermiculite (29) and has a thickness of from about 0.5 to 10 mils and the add-ons of the vermiculite to the web are from about 10% to 50%.

Dependencies are inferred from the claim text.