What is a hip jack?

• A. A beam that runs along the hip line
• B. A device used to jack up the house during foundation repair
• C. It extends from the top plate of the building to the hip rafter.
• D. A type of tie rod at the hip

Answer: (C)

In roof framing, a hip jack is a short rafter piece that connects the top plate of the wall to the hip rafter, filling the space between the hip rafter and the wall. This member helps transfer loads from the hip rafter down into the wall and supports the geometry of a hip roof. It’s not a beam along the hip line, not a device used to jack up a house, and not a tie rod, so those options don’t describe the actual structural role of a hip jack. Understanding this helps when assessing how roof loads travel and where failures could occur during a fire or structural collapse.