Deciphering ART DU TRAIT

In the last post on

ART DU TRAIT PRATIQUE DE CHARPENTE, by EMILE DELATAILLE I used the technique of following the footprint of the hip rafter to develop the claw angle on the jack rafter. In that post the hip rafter was plumb to the ground plan. In this post the hip rafter is rotated, like the legs of a saw horse. The same technique of following the footprint of the plumb hip rafter works for the rotated hip rafter as well.

Perspective View of the Rotated Hip Rafter

&

Jack Rafter With Claws

Ground Plan with the Hip Rafter Rotation.

Develop the Hip Rafter Profile Slope.

Use the same width of the hip rafter rotation in plan view to draw the hip rafter profile width.

The hip rafter in profile develops the footprint of the hip rafter in plan view.

Drawing in the lines following the hip rafter footprint develops the lines for the claw angle on the jack rafter.

Here I transferred the lines to the jack rafter material by placing the jack rafter material directly over the jack rafter in profile. 

 This drawing shows how to draw  line # 1 parallel with the eave line from the hip rafter footprint to the edge of the jack rafter.  Line # 2 is parallel with the jack rafter slope from point C2. Drawing a line parallel with the eave line from point C5 develops the intersecting point C6 for the jack rafter claws.