Jack Beam
A beam used to support another beam, rafter or truss and eliminate a column support.
Jack Truss
A truss used to support another beam, rafter or truss and eliminate a column support.
Jamb
The vertical framing members located at the sides of an opening.
Jib Crane
A cantilevered or suspended beam with hoist and trolley. This lifting device may pick
up loads in all or part of a circle around the column to which it is attached.
Jig
A device used to hold pieces of material in a certain position during fabrication.
Joist
Light beam for supporting a floor or roof.