We’re lucky to have relationships with the expert instructors and craftspeople at Seattle Central College’s Wood Technology Center. In this video series, Catie Chaplan, a veteran instructor, guides us through some of the foundational carpentry concepts and methods for framing a basic equal-pitch hip roof, as taught in the center’s curriculum.
Catie is dedicated to teaching the next generation of highly skilled carpenters. As a professional builder for 31 years, she's worked for general contractors, boat builders, and cabinet shops, and has owned and operated a residential design-build company in Seattle since 2002. She's been an instructor at the Wood Technology Center for the past 25 years, where she currently leads the carpentry program and teaches computer-aided design (CAD) and computer numeric control (CNC) classes.
Throughout the Framing a Hip Roof series, Catie shows us how to calculate theoretical hip roof framing (meaning that the calculations go to the very center of the roof), then how to adjust those calculations for the thickness of the materials used in different parts of the roof where pieces come together (this is called adjusting for "reality").
In this video from Catie’s virtual course curriculum, she walks us through the basic elements of an equal-pitch hip roof. Watch the overview above or read below for a summary of the terms discussed.
What is a hip roof?
A hip roof is a roof design where four or more planes of the roof slope downward from the ridge to the eaves. Unlike a simpler gable roof, hip roofs are a bit more challenging to construct, as they introduce more complex rafter configurations.
Characteristics of a basic hip roof
Ridge
The ridge (also called a ridge board or ridge beam) is the horizontal piece of lumber where two opposing planes meet to form a peak. On an equal-pitch hip roof, there are two additional planes formed by four rafters (two rafters at either end) that extend at 45-degree angles from each end of the ridge.
Hips
The hips of the roof refer to the rafters that extend diagonally from the ends of the ridge to the four corners of the roof.
Common rafters
Common rafters are perpendicular to the ridge and run all the way from the ridge to the wall. An equal-pitch hip roof, like the one shown in the video above, is completely symmetrical: Rafters on either side of the ridge match up with each other on opposite sides of the ridge to create opposing tension.
Hip roofs often have a common rafter at the end of the ridge, butting up against the two hips.
Jacks and hip jacks
A common rafter that doesn’t make it all the way to the ridge is called a jack. In the rendering, the rafters at the corners of the roof are called hip jacks, as they stop at the hip before reaching the ridge. Hip jack geometry is identical to common rafters, with the exception that they stop short of the ridge.
King common rafters
Some hip roofs (including the example in the video) have two common rafters at each end of the ridge. The rafter at the center of the triangle (the longest) is sometimes called the king rafter.
Eaves
Eaves are a type of roof overhang that is level to the ground. Rakes are another type of overhang that follows the incline of a gable end. Unlike gable roofs—which have both eaves and rakes—hip roofs only have eaves at the overhang. The eaves are all parallel to the ground and are sometimes trimmed with fascia.
Throughout this series, Catie will break down different aspects of framing a basic, equal-pitch hip roof. Stay tuned for more video tutorials in the weeks to come.