What is the function of a hip jack?

The function of a hip jack is primarily to extend from the top plate to the hip rafter. Hip jacks are typically utilized in roof framing, where they help create a connection between the vertical structure of the wall and the angled roof, specifically at the point where the hip rafter meets the roof's edge. This is crucial for distributing the weight of the roofing material and ensuring structural integrity at the hip's junction.

While supporting the roof structure is essential, hip jacks play a specific role by linking the wall to the hip rafter itself, rather than providing overall support. Insulation, while important in construction for thermal efficiency, is not a function of hip jacks, as these are primarily structural components rather than entities that provide thermal resistance. Lastly, hip jacks are not responsible for connecting the roof to the walls in a general sense, but rather they form a connection in a particular context involving hip roofs.