Jack studs

A jack stud is a stud that has been cut down to be placed above and/or below an opening. The jack stud provides support to the lintel trimmer and sill trimmer.

Two diagrams. The first shows a jack stud above a lintel (head trimmer). Lintel housing for a jack stud is not permitted. A nogging to the next stud in the vicinity of the head trimmer is considered good practice. The second diagram shows the breadth of the lintel.