A method and apparatus for venting a mold for vulcanizing a tire is provided. The mold comprises a plurality of tread segments for forming the tread on a green tire, wherein each of said tread segments further comprises an outer cavity plate having an interior surface and an exterior surface, the cavity plate having a plurality of channels. Each of the channels has a vent hole extending from the channel to the exterior surface of the outer cavity plate, and a rib mounted over the channel. The adjoining surface of the rib mating with the interior surface of the cavity plate, wherein one of the mating surfaces has a roughened surface forming a vent passageway with the interior surface of the cavity plate for venting mold gasses from the interior of the mold to the exterior of the mold. The invention may further include a blade and blade passageway wherein the blade outer surface has a rough outer surface for forming a vent passageway with the blade passageway.