How to Frame a Cross Hip Roof

Hip Roof

• A hip roof slopes back from all four sides of a rectangular building, the slopes meeting at a ridge at the highest point of the roof. This is in contrast to a gable roof, in which the roof slopes up from two parallel sides of the building to meet at a peak line, while the other two sides are vertical, forming triangular gables at the ends of the building. Both hip roofs and gable roofs are framed using a system of rafters and ridge beams.

Cross Hip Roof

• When perpendicular hip roofs intersect in a building's roof plan, a cross hip roof is formed. The intersection of the roof slopes creates inside corners, called valleys, where the slope changes direction. The same kind of valleys are formed when two gable roofs intersect, and this part of a cross hip roof is framed the same way that a cross gable roof is framed.

Ridges, Rafters and Rafter Ties

• The ridge beam is a horizontal timber that forms the peak of the roof. Long rafters, called common rafters, slope up from the top of the exterior walls to meet at the ridge. In a hip roof, the rafters that slope up diagonally from the corners of the building to meet the end of the ridge, thus forming the end slope of the roof, are called hip rafters. The shorter rafters that have one end resting on the exterior walls and the other end resting on a hip rafter are called hip jacks. Rafters are tied together with horizontal timbers that keep the rafters from pushing the exterior walls outward; when these ties are located at the bottom ends of the rafters and rest on the top of the walls, they are called joists, and when they are higher up the slope, they're called collar ties.

Valleys

• Where two perpendicular ridges meet, a long rafter, called a valley rafter, slopes diagonally from the ridge intersection to the corner where the corresponding intersecting walls meet. The shorter rafters that run between the ridges and the valley rafters are called valley jacks.