Definitions of Terms under Alphabet J
Jamb Stop

In interior door frames the stop is the material attached to the jamb to which the door closes against. In exterior door-frames, it is the molded-in rebate surface of the jamb against which door panels close and seal.

Jamb Jack

A fastener device for fixing a door frame to a wall structure which allows the space or margin between the frame and the structure opening to be varied by turning the fastener screw.


A vertical perimeter frame of a door unit.