The vertical side member of the elevator landing door frame that defines the sides of the door opening and supports the door sill and architrave.
Full Definition
Door jambs are the left and right vertical members of the landing door frame assembly. They define the width of the door opening, provide the structural mounting for the sill brackets, and carry the load from the door header. In steel door frames, jambs are typically formed steel channel or angle sections. In masonry construction, jambs are embedded in the wall opening. Jamb plumb and parallelism are critical to door alignment: a twisted or out-of-plumb jamb causes binding of the landing door panel and misalignment of the door lock.
