A thermal insulating roofing board of bonded, randomly and spacedly positioned individual, discontinuous glass fibers, with an asphaltic saturated surface layer including bundles or strands of glass fibers distributed over the upper surface of the board under a top surfacing sheet, said board being produced by forming and discharging individual, discontinuous fibers downwardly with particles of binder intermingled therewith to form a pack upon a conveyor receiving surface, compressing the pack under a roller, depositing bundles or strands of glass fibers upon the upper surface of the pack, compacting the pack in board form and curing the binder particles to dimensionally stabilize the pack in such form, applying heated asphalt to the upper surface of the stabilized compacted pack to impregnate the upper stratum thereof, including the bundles or strands of glass fibers and applying a top surfacing sheet over the applied asphalt.