A method of forming a thermally enhanced extrudate for a door or window includes providing an extrudate including a channel shaped to receive glass or a frame and having a completely enclosed cavity. The method further includes forming openings in a first flange of the extrudate. The remaining portion of the first flange form bridges that extend between a first wall and a second wall. The method further includes position a flowable material into the cavity through the openings. The flowable material cures to create a solid insulation material in the cavity and the bridges resist warping of the extrudate as the flowable material cures.