Abstract: The disclosure relates generally to a window assembly designed to facilitate the construction process by providing a simple and efficient method for joining mullion members and frame members along a window joint. The assembly includes a mullion end cap with a seal extending around the periphery of the end cap to help minimize moisture entry into the window assembly via the window joints. In addition, the seal includes fastener bosses designed to seal against fasteners extending therethrough to help seal the joint without need for separately applying a silicone or other sealant in a post-assembly process.

Abstract: A corner joint for fenestration frames and the like includes first and second frame members having hollow interiors and ends joined in abutment. A corner key insert has legs inserted into the ends of the frame members. End portions of the legs engage the hollow interiors of the frame members forming adhesive cavities within the frame members and along the end portions of the corner key legs. Adhesive is disposed within the cavities to bond the corner key legs to the frame members, thereby creating a structural joint between the frame members. The corner key insert may include multiple injection ports for delivering adhesive to the cavities from a selected side of the frame assembly. Legs of the corner key may have notches formed therein to receive an internal wall of the frame members, and distal ends of the legs may include a flow barrier that contours along the notches.