Constructing hip roofs is not easy. It requires patience and carpentry skill. However, some house designs call for hip roofs, in which case you have no choice but to face and overcome the difficulty. Knowing how to build a hip roof is a valuable skill and will impress anyone familiar with the challenges such projects present. There is a tremendous amount of pride in seeing your hard work pay off with a high-quality product.
Consult architectural plans to determine the desired roof pitch. The pitch is usually written as x/12. For example, a 5/12 pitch is one where there are 5 inches of vertical rise for every 12 inches of horizontal run. This is called a 5 pitch. Hips are rarely very steep or very shallow. Most will be built with a 5, 6 or 7 pitch.
Cut the ridge board and four common rafters. Common rafter cuts are determined by the roof's pitch. Common rafters are installed perpendicular to the ridge board and the wall top plate and run between the two. Install the ridge board level with two common rafters supporting it on each side.
Cut and install the four hip rafters. Hip rafters extend from the building's four corners to the two ends of the ridge board. Hip cuts can be determined from the roof's pitch using a rafter-angle square. Hip cuts are more complex than common rafter cuts because they are compound cuts---they are cut for the roof pitch and the angle between the ridge board and the building's corners.
Fill in the remaining common rafters. Cut and install one common rafter every 16 inches along the ridge board on both sides, ensuring that they are perpendicular to both the ridge board and the wall top plate. Install one common rafter at each end of the ridge board, running perpendicular to the end wall top plates. Nail rafters to the ridge and to the wall top plate with 16d framing nails.
Cut and install hip jack rafters. Hip jacks run from the wall top plate and end into a hip rafter. They fill in between common and hip rafters. Hip jacks are the most complicated rafters to cut for a hip roof since they must run into the diagonal hip rafters. Use the rafter-angle square to determine hip jack cuts. Install the hip jacks in pairs, one pair at a time working up each of the four hips. Cover the roof framing with plywood sheathing.
Framing roofs can be hazardous. Use extreme caution when working off the ground, and be aware of people working below you. Be careful with power tools.