Jack Rafter – Defined under “Rafter Types”.

Jack Stud – A block or short stud nailed to rough door or window studding to add strength and provide a solid bearing for the lintel and nailing member for the finished door jamb or window frame.

Jalousie Window – Defined under “Window Types”.

Jamb – The side member or lining of a doorway, window or other opening.

Joinery – The fitting and joining together of pieces of wood into a finished wooden article or structure. It refers to “fine carpentry”, “bench carpentry” and other fine forms of woodworking.

Joint Cement – A powder that is mixed with water and applied to the joints of gypsum-wallboard.

Joints –

Finger Joint – A glued joint consisting of a series of interlocking fingers, precision machined on the ends of two pieces of wood to be joined.

Lindermann Joint – A glued dovetail joint, shaped by a Lindermann jointer, joining two pieces of wood edge to edge longitudinally.

Joist – One of a series of horizontal wood members, usually 2-inch normal thickness, used to support a floor, ceiling or roof.

Joint Bridging – Short diagonal braces placed between floor joists as stiffeners.

Joist Hanger – A steel section shaped like a stirrup, best so it can be fastened to a beam to provide end support for joists, headers etc.