A set of angles that describe the compound intersection of beams in hip and valley roofs. They were developed by Rees Acheson for Benson Woodworking and by Ed Levin for Paradigm Builders in the 1990s, building on Frank Martindale’s Bevel Angles, a steel detailing handbook published in 1948.
Download the Excel spreadsheet of Hawkindale angle calculations. By specifying rafter slopes and deck and wall angles, you can obtain the resulting layout and cutting angles at all plausible connections in a timber-framed compound roof.
These articles (from TIMBER FRAMING) by Rees Acheson and Ed Levin explain the genesis and use of the Hawkindale Angles.
A suite of SketchUp extensions specifically for timber framers, designed by Clark Bremer of Northern Lights Timber Framing.