Abstract: An extruded aluminum sill member is supported by and attached to a wood base member which also supports a longitudinally extending inner wood trim member. The sill, base and trim members define a longitudinally extending cavity which receives a vertically adjustable rail member. The rail member has longitudinally spaced captive screws which are threaded into inverted T-nuts confined within laterally extending slots formed within the wood base member, and the trim member covers the slots. The sill member also extends under a jamb or mullion and a fixed side panel, and a snap-in extruded plastic cap covers the cavity under the panel and has an upwardly projecting and inwardly curved flange with a flexible lip for engaging the outer surface of the panel to form a water-tight seal.

Abstract: An extruded aluminum sill member is supported by and attached to a wood base member which also supports a longitudinally extending inner wood trim member. The sill, base and trim members define a longitudinally extending cavity which receives a vertically adjustable rail member. The rail member has longitudinally spaced captive screws which are threaded into inverted T-nuts confined within laterally extending slots formed within the wood base member, and the trim member covers the slots. The sill member also extends under a jamb or mullion and a fixed side panel, and a snap-in extruded plastic cap covers the cavity under the panel and has an upwardly projecting and inwardly curved flange with a flexible lip for engaging the outer surface of the panel to form a water-tight seal.