A sliding door assembly has a frame with a movable panel and a fixed panel. The movable panel has a pair of rollers that roll along a header located above the panels with the rollers attached to the movable panel via posts that pass through a channel on the header. The posts pass through a curved section of the channel whenever the movable panel is proximate its closed position and a straight section of channel when the movable panel is traveling laterally. The movable panel presses against a gasket located on the frame components surrounding the movable panel wherein one or more latches press the movable panel against the gasket whenever this panel is in the closed position. Valve is positioned within a weep hole on the threshold in order to prevent water from seeping into the building via the bottom of the door assembly.