Saturday, July 25, 2015

Ancient Knowledge Tour

Ancient Knowledge Tour of Roof Framing Geometry

Sim Ayers & Billy Dillon

Saturday Oct. 17
San Francisco, California

The class has been moved to BuildZoom's office in  San Francisco

501 Folsom St, San Francisco, CA 94105,
8:00am to 5:00pm
Registration cost is $100.00

Sponsored by BuildZoom BuildZoom

Simpson Strong Tie
JLC Magazine -- The Journal of Light Construction -- Hanley Wood Company
WindsorOne -- Protected Trim

This will be a hands on workshop/class on advanced roof framing. 
Cut complex roofs like the master carpenters of Europe.

Tools required for the class:

2-45º drafting triangles
1-30º - 60° drafting triangle
straight edge
framing square (no rafter tables needed)
drafting protractor
drafting pencils
colored drawing pencils
Japanese Pull Saw (handsaw)

Optional Tools for the class, if time allows for Hip Rafter Edge Bevel:

Draw Knife
Hand Plane

Topics covered in the workshop:

Roof Framing Kernel , with fold out and fold down roof surface planes
Rule of Thales, converting degrees to radians i.e. 57.3
Eyebrow Dormers, Groin Vaults, Curved Hip Rafters  using ordinates
Scribing timbers using a French plumb bob
Transfer angles and lines to the stick (timber), grasshopper method.

Ad Quadratum -- Octagonal Roof Framing
Plumb To the Earth
Trait Car -- Perpendicular

Ad Triangulum
Hexagonal Roof Framing
Layover Valley Rafter
Curved Rafters

'L'Art du Trait'
Roof Framing 

Schräge Sparren 
Canted Rafters
French Devers de pas drawing technique
German Shadow Line drawing technique

Treteaux Angles
Rotated Hip Rafters
Roof Axis Plane
Pentagonal Roof Framing

Hip Rafter
Backing Angle
Edge Bevel
Basic Shift

Rafter Claw -- Barbe Angles
Eyebrow Dormers

The Witches Cut
Square Tail Fascia Angles

Besides the roof framing geometry, if time allows, for Simpson Strong Tie --- We'll show you how to install HDU hold downs correctly and how to nail plywood shear wall plywood correctly, when the On Center spacing is 2" O.C.


  1. Do you know about rhombic roof ? Where can I get the information of the rhombic roof ? Or does it has any similar name ? I'm in an archi project and it hard for me to get any source about it..

    1. Rhombic may refer to: Rhombus, a quadrilateral whose four sides all have the same length (often called a diamond)
      Here's more information on the Rhombic Roof.


  2. I would like to attend roof framing geometry class is there another one scheduled thanks

  3. Emilio, the next class might be in March in Providence Rode Island. No details yet.