|jack stud: |
A jack stud is a structural member of a window opening. It transmits the weight of the header to the floorboards or joists. Depending on the width of the window or wall, a jack stud may be a 2x4, a 2x6, or several of these sistered together.
A master (for example, master carpenter Norm Abram or master plumber Rich Trethewey) is the holder of a master's ticket, a certification that the individual possesses high levels of skill in their chosen discipline. Exactly how one qualifies for a master's ticket varies from state to state, but generally it requires demonstrations of skill and knowledge and years of experience.
OSB is shorthand for oriented strand board. This engineered product contains strands of wood, oriented so the fibers align, and bonded with extremely powerful adhesive. Once the adhesive cures, it is chemically inert and there is no outgassing. Previously limited to sheet lumber, in recent years manufacturers have used variations on this technology to create engineered dimensional lumber as well.