Improved frame assembly for doors, windows and the like is provided. The assembly includes a frame defining an opening for receiving and retaining a central panel. The frame is formed from two joined skins which may be molded in the same mold and which are provided with inwardly extending flanges having notched areas on opposite sides of the flanges such that the skins can be joined together to form a lap joint on the exterior edge and to seal a central panel in the opening. Foamable insulating material is provided as a core between the two skins with a separate sealant material provided to seal the central panel. Passage means are provided for introducing the sealant material and the insulating material.