Timber Framing Angle: P1
P1 = Purlin Saw Miter Angle on the face of Purlins or Bird-Block set perpendicular to the plane of the roof. Purlin or Frieze Block cut perpendicular to roof surface.
HawkinDale Formula
- P1 = arctan (sin S ÷ tan D)
Hip-Valley Roof Ratios Angle Formulas
- P1 = arctan (sin S ÷ tan D)
- P1 = arctan (sin (common rafter slope angle) ÷ tan(plan angle))
- Frieze Block Saw Miter Angle = arctan( sin ( Pitch Angle ) ÷ tan( Plan Angle ))
- Square Tail Fascia Miter Angle = arctan( sin ( Pitch Angle ) ÷ tan( Plan Angle ))
- Purlin Miter Angle = arctan( sin ( Pitch Angle ) ÷ tan( Plan Angle ))
The Hip-Valley Roof Ratios Angle Formulas were developed by Joe Bartok.
The Timber Framing Hawkindale Angle Formulas were developed by Rees Hawkins Acheson from the Martindale Hip and Valley Roof Angles and Hawkindale angle drawings by Ed Levin of the Timber Framers Guild.
The Hawkindale angles were based on the book by Frank L. Martindale "Bevel Angles for Three Dimensional Connections" 1948 that was based on the book
"Hip and Valley Design" by H. L. McKibben and L. E. Gray published in 1912.