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

Co-Sponsors

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:

12”compass 

2-45º drafting triangles

1-30º - 60° drafting triangle

straight edge

scissors

framing square (no rafter tables needed)

drafting protractor

drafting pencils

colored drawing pencils

eraser

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.
DoppleShifter

Ad Quadratum -- Octagonal Roof Framing

Plumb To the Earth

Trait Car -- Perpendicular

Ad Triangulum

Hexagonal Roof Framing

Layover Valley Rafter

Curved Rafters

Schiftungen

Dachausmittlung

'L'Art du Trait'

Roof Framing 

Geometry

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

Backenschmiege

Abgratungswinkel

Hip Rafter

Backing Angle

Edge Bevel

Basic Shift

Klauenschifter

Rafter Claw -- Barbe Angles

Eyebrow Dormers

Hexenschnitt

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.

Curved Hip Rafters

I came across this method of drawing out the curves of hip rafters in a Carpentry & Building magazine published in 1880 and thought it was pretty easy way to establish the curve of any hip rafter using this method. It can be used for the curved hip rafters on flared radius eave rafters, curved hip rafters on bay windows or a hip rafters with any eave angle.

To use this method draw the elevation view of the common rafter and hip rafter above the plan view of the radius rafters. Draw the radius/ Arc of the common rafter. Then draw equal spaced horizontal lines that intersect with the hip rafter slope line in elevation view. Drop some perpendicular line where the horizontal lines intersect the hip rafter slope line and the common rafter slope line . Then draw rectangular boxes to establish the cure of the hip rafter based off the curve of the common radius rafter.

Geometric drawing of the curve of a standard hip rafter and Octagon hip rafter  with a common radius rafter. 

Drawing for the curve of the bay window hip rafter and the curve of the hip rafter against the wall of a bay window.

Section of a Bay window in Plan View

How to draw out the arc of the common radius rafter on a bay window.

Geometric drawing of the curve of bay window hip rafter and the curve of the hip rafter against the wall of a bay window using the rectangular boxes to establish the curves of the rafters.