Abstract: An elongated lighting enclosure for tubular light bulbs has a downwardly opening plastic housing within which a lighting fixture chassis and lamps are mounted. The housing has a top, sides and ends, the sides each having an inwardly opening channel with an inturned lower flange at its lower edge. A resilient gasket is seated in the inwardly opening channel and along the ends. An upwardly opening lens having a bottom, sides and ends and an outturned lip around its perimeter is received by the inwardly opening channels and engages the resilient gasket. The resilient gasket urges the lens against the housing to effect a positive pressure seal along the sides. A downwardly opening metal liner which generally conforms to the shape of the housing may be provided to accommodate the lighting fixture chassis.