Abstract: A door sealing assembly for closing the gap between the lower edge of a door and an underlying floor surface includes an elongated threshold mounted to the floor beneath an overhead door. The threshold presents a plurality of slots which can be aligned with and coupled to fasteners anchored to the floor surface itself. The lower surface of the threshold further includes an adhesive layer which further contributes to the secure mounting of the threshold to the floor as well as inhibiting draught between the floor and threshold. The upper surface of the threshold presents a recess extending along the length thereof. A seal is attached to the lower edge of the door and is configured to nest within the recess. A resilient sheet of impervious material extends across the recess when the door is in an open position and is depressed into the recess by the seal when the door is moved to a closed position to close the gap between the lower edge of the door and the underlying floor surface.