In roofing terms, a hip describes a structural assembly that forms the return around the external corner of a roof. For a standard hip to be created, two perpendicular planes of a roof, both of the same pitch meet at a 90-degree external corner, where a hip rafter is installed to form the primary structural member of the hip assembly. In this standard configuration, the hip rafter spans from the corner of the wall plates to the geometric intersection of the crown rafter and last common rafter at the ridge. Both of these rafters receive into the ridge board to create a perfect housing for the top cut of the hip rafter. The hip rafter features a double edge bevel at the relevant pitch to allow it to fit tightly into this intersection. Once the hip rafter is situated, jack rafters are from the wall plate to the hip rafter, continuing the O/C layout of the standard rafters. These jack rafters feature a regular bird’s mouth at the plate, and a compound jack plumb cut at their top where they meet the hip rafter. Where two standard hips are installed uniformly at the end of a roof, a hip end is created.  

More complex hip variations exist that tie together two planes of a roof that feature varying pitches or that meet at irregular angles of presentation. We will study these in depth later. For now, we shall focus on the standard hip. 

What are the criteria of a hip/hip end?

A standard hip must be installed to the relevant pitch in order for the two planes of the roof to meet at the correct angle. The correct angle of plumb and seat cut must be made on the hip rafter in order to ensure that a snug fit is achieved both at the ridge intersection and at the corner of the wallplates. If required, a backing angle must be installed on the hip rafter to ensure that the roof covering system is suitably supported. The jack rafters must be installed at regular intervals following the on-centre layout of the common rafters in order to fully support the roof covering system. The angles of the jack rafters must also be suitable to tidily receive into the side of the hip rafter and be adequately fixed as such.