A drive assembly for a slide out in an expandable enclosure, the drive assembly comprising a beam attachable to the slide out, the beam having a first row of teeth and a second row of teeth thereon, the first row of teeth and the second row of teeth extending parallel to each other on opposite sides of the beam wherein the teeth in the first row of teeth are offset relative to the teeth in the second row of teeth and a drive gear having a first gear wheel engagable with the first row of teeth and a second gear wheel engagable with the second row of teeth, and an actuator coupled to the beam to selectively extend and retract the beam.