Moisture impermeable spacer for a sealed window unit

A pultruded spacer for a sealed window unit comprising an elongate body having two spaced side surfaces each for engaging a glass pane such that the glass panes are held spaced in the sealed window unit, a top surface for facing inwardly of an edge of the window unit, a bottom surface for facing outwardly of an edge of the window unit and a hollow interior surrounded by said surfaces, said top surface including means therein allowing communication of moisture through the top surface to the hollow interior, the spacer consisting of a thermoset resin material reinforced by a fibrous material, said fibrous material comprising a plurality of elongate fibrous elements extending continuously longitudinally of the elongate body, and an impermeable layer of a moisture impermeable material embedded in the resin material so that it extends continuously longitudinally of the spacer and continuously across the spacer from a position part way down one side surface, across the bottom surface to a position part way down the other side surface, the impermeable layer being fully covered on both sides thereof by said thermoset resin and said fibrous material, said impermeable layer comprising a laminate having a first layer of foil and a second layer formed of a supporting material and attached to the foil layer on one side thereof, the supporting material having a character to provide structural strength for the laminate to prevent tearing of the foil and effective bonding to the thermoset resin to prevent delamination of the body at the laminate.