How Do I Draw The Angles In Roof Framing

Das neue Buch vom alten Wissen der Schiftung
The new book on the ancient knowledge Schiftung

The new book on the aboriginal noesis Compound Joinery
The new book on the aboriginal noesis Roof Framing
The new book on the ancient knowledge Roof Framing Geometry

pastBernd Küppers

More images and information on the book can be constitute at this link.

Image from Bernd's Facebook page on Shiftung.

Verkanteter Kehlsparren in German = Tilted-Canted- Rotated Valley Rafter

Looking at page 52 in his volume I decided it was time to report the valley rafters rotated into the roof surface plane. The same geometric techniques used for hip rafters rotated into the roof surface aeroplane can also exist used for the valley rafters rotated into the roof surface airplane. Some of the geometry used for valley rafters rotated into the roof surface plane isempirical-blazon knowledge. Information gained past means of observation, experience, or experiment.From this empirical noesis we know the valley jack rafters miter head cut will exist 90° and the bevel cut, top cut, will be the aforementioned as the jack rafter bevel angle for plumb hip-valley rafters.

Nosotros also have a language problem when we're studying Verkanteter Kehlsparren or Verkanteter Gratsparren . What practice we telephone call each side of the canted hip or valley rafter rotated into the roof surface aeroplane.

Principes du dévers: la sauterelle

Principles of cant: the grasshopper

he labels each side of the rotated hip rafter in programme view as A for the side of the roof the hip rafter is rotated into and the canted side every bit Bthe DPside of the hip rafter.

DP = Dévers De Pas .... need a German proper name for this side of the canted hip rafter.

TC = Trait C arré = Perpendicular .... need a German name-word -- senkrecht ?

I purpose labeling all canted hip or valley rafters in plan view as TC, for the side the hip-valley rafter is rotated into, and DP as the side of the hip-valley rafter that'south canted-Tilted from plumb.

Case for the TC side of the hip-valley rafter is rotated into the roof surface airplane:

Plumb hip-valley rafter

Jack Rafter Miter Angle = 33.69° = Roof Gradient Angle

Jack Rafter Bevel Bending = 39.76°

Rotated hip-valley rafter

Jack Rafter Miter Angle = 90.00°

Jack Rafter Bevel Angle = 39.76°

For equal pitched roofs for the canted-DP side of the hip-valley rafter:

Plumb hip rafter

Jack Rafter Miter Angle = 33.69° = Roof Gradient Angle

Jack Rafter Bevel Angle = 39.76°

Rotated hip rafter

Jack Rafter Lower Claw Bending = Roof Slope Angle

Jack Rafter Bevel Bending = 39.76°

And so the only angle nosotros demand to describe out or calculate for the jack rafters for the rotated hip rafter is the Jack Rafter Upper Claw Angle on the DP side of the hip rafter.

Since the canted-tilted valley rafter is just an upside down hip rafter the but bending we demand to calculate is the Jack Rafter Upper Lower Bending on the DP side of the valley rafter.

Drawing from 1 of my studies on the hip rafter rotated into the roof surface plain using more of the French technique "l'fine art du Trait" rather than the German Shiftung technique. Some times the High german Shiftung roof framing geometry technique for developing the geometry of a compound joint just has likewise many development lines. Hither in this cartoon, you can apply my Precept #3 for the line that develops the Upper Claw Bending on the jack rafter on the DP side of the hip rafter. It would develop the jack rafterLower Hook Angle for the DP side of thevalley rafter.

Roof Framing Geometry Proposition – Axioms # iii:
The intersection of the DP Lines of two rafters define the line for the upper claw angle on the rafter.

In this drawing of the rotated hip rafter the Upper Hook Bending for the jack rafter on the DP side of the hip rafter is 12.11976°.

In this drawing of the rotated hip rafter the Upper Claw - Miter Angle for the jack rafter on the TC side of the hip rafter is 90.00°.

In this drawing of the rotated valley rafter the Upper Claw Bending for the jack rafter on the DP side of the hip rafter is 52.00°, same as the roof slope angle, and the Lower Claw Angle is 12.11976°.

The Lower Hook Angle is 12.11976° for the jack rafter on the DP side of the rotated valley rafter.
Aforementioned equally the Upper Claw angle for the jack rafter on the DP side of the rotated hip rafter.

Yous can as well use my tréteaux roof framing calculator to verify these angles.

Trèteaux Angles: P16a-DP
P16a-DP = Adjacent Side Jack Rafter Miter Angle on DP Side Of Hip Rafter on Face Perpendicular To Roof Surface, Lower Claw Bending ... this would be the Upper Claw angle for the jack rafter on the DP side of the rotated valley rafter.

Trèteaux Angles: P17a-DP
P17a-DP = Adjacent Side Jack Rafter Miter Angle on DP Side Of Hip Rafter on Face Perpendicular To Roof Surface, Upper Hook Bending... this would be the Lower Claw bending for the jack rafter on the DP side of the rotated valley rafter.

Trèteaux Angles: P18a-DP

P18a-DP = Adjacent Side Jack Rafter Bevel Angle on DP Side Of Hip Rafter on Face Set in Roof Surface

This would be the dorsum bevel, top cutting, for the jack rafter on the DP side of the rotated valley rafter.