SBE Builders

Strong Built Establishments Builders

SBE Builders is a commercial and residential framing contractor located in Discovery Bay California. Dedicated to the art of Carpentery & Roof Framing. We are the professionals for the future of the craft of carpentry.

Unequal Pitched Roof Gable Calculator
with equal height plate line.
Major Rafter Pitch Or Major Pitch Angle Minor Rafter Pitch Or Minor Pitch Angle Ridge Width Building Span
feet
inches
frac
Major Rafter Seat Cut Rafter Material Depth Minor Rafter Seat Cut Minor Material Depth Overhang Show Feet Inches

Unequal Pitch Roof Trigonometry
Calculating unequal pitched roofs is easy if you know what trigonometry functions to use. The
formulas below use the law of sines to calculate the unknown length or angle.


Known Variables: Major Pitch Angle & Minor Pitch Angle & Major Run
Calculate Minor Run
Minor Run = Major Run  ( tan(Major Pitch Angle)  tan(Minor Pitch Angle))
Minor Run = Major Run  ( Major Pitch  Minor Pitch)
Known Variables: Major Pitch Angle & Minor Pitch Angle & Minor Run
Calculate Major Run
Major Run = Minor Run  ( tan(Minor Pitch Angle)  tan(Major Pitch Angle))
Major Run = Minor Run  ( Minor Pitch  Major Pitch)
Known Variables: Major Pitch Angle & Minor Pitch Angle & Span
Calculate Major & Minor Runs
Major Run = ((Span  sin(Minor Pitch Angle))  sin (180 - Major Pitch Angle - Minor Pitch Angle))  cos( Major Pitch Angle )
Minor Run = ((Span * sin(Major Pitch Angle))  sin (180 - Major Pitch Angle - Minor Pitch Angle))  cos( Minor Pitch Angle )
Known Variables: Major Pitch Angle & Minor Pitch Angle & Span
Calculate Major & Minor Rise
Major Rise = ((Span  sin(Minor Pitch Angle))  sin (180 - Major Pitch Angle - Minor Pitch Angle))  sin( Major Pitch Angle )
Known Variables: Major Pitch Angle & Minor Pitch Angle & Span
Calculate Major & Minor Rafter Lengths
Major Rafter = (Span  sin(Minor Pitch Angle))  sin (180 - Major Pitch Angle - Minor Pitch Angle)
Minor Rafter = (Span * sin(Major Pitch Angle))  sin (180 - Major Pitch Angle - Minor Pitch Angle)
Known Variables: Major Pitch Angle & Major Run & Span
Calculate Minor Pitch & Minor Run
Minor Pitch Angle = arctan((Major Run  sin(Major Pitch Angle))  (Span - Major Run ))
Minor Run = ((Span * sin(Major Pitch Angle))  sin (180 - Major Pitch Angle - Minor Pitch Angle))  cos( Minor Pitch Angle )
Known Variables: Minor Pitch Angle & Minor Run & Span
Calculate Major Pitch & Major Run
Major Pitch Angle = arctan((Minor Run  sin(Minor Pitch Angle))  (Span - Minor Run ))
Major Run = ((Span  sin(Minor Pitch Angle))  sin (180 - Major Pitch Angle - Minor Pitch Angle))  cos( Major Pitch Angle )

Law Of Sines
C = 180 - (A + B)
a = ( c  sin( A) )  sin( C)
a = ( b  sin( A ) )  sin( B)
a = ( b  sin( B ) )  sin( A)
b = ( c  sin( B ) )  sin( C)
b = ( a  sin( B ) )  sin( A)
b = ( a  sin( A ) )  sin( B)
h = b  sin( A )
h = a  sin( B )
c = ( a  sin( C ) )  sin( A)
c = ( b  sin( C ) )  sin( B)

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SBE Builders
SBE Builders
5305 Laguna Ct.
Discovery Bay, California 94505
(925) 634-6022 • Fax: (925) 634-6022
Commercial & Residential Framing Contractor
American Carpenter and Builder
California Licensed General Building Contractor
CA LIC.#  546126


Roof Framing Geometry

  • Roof framing geometry is empirical-type knowledge.
  • Information gained by means of observation, experience, or experiment.
  • From ground Line 0: Z1, Z2, Z3 etc...
  • To Roof Axis 0: A1, A2, A3 etc...
  • To the bring back line 0 for scribing: B1, B2, B3 etc...

Roof Framing Geometry Blog

Rafter Tools for Android
With Quad Tetrahedra Analytic Algorithm Technology.
Helping apprentice carpenters on their journey to becoming master carpenters with Certification in roof framing.

Rafter Tools+ for iPhone

Rafter Tools+ is a rafter calculator for complex roof framing angles that other roof framing calculators don't offer.

RafterTools+

Stair Tangent for iPhone

This iPhone app is for rough frame carpenters that don't build stairs everyday, but could use an stair app calculator to check their stair building calculations. Build a set of stairs that you are gonna be proud of. With Stair Tangent you can elimenate cumulative math errors when building - constructing stairs.

Stair Tangent
stairtangent.com

Crown Molding Tools
crownmoldingtools.com

Crown Molding Tools  

Carpenters Of Steel

Canadian & American Geometric Roof Framing Development
using a Steel Framing Square

Geometric Roof Framing Development for Irregular Hip Roof Calculations
using a Steel Framing Square

Geometric Development of Tetrahedron
using a Steel Framing Square

Hip Rafter Backing Bevel Angles from 1565 to 2013

Applied Geometry and Euclidean GeometryA lesson in Applied Geometry and Euclidean Geometry

This Is Carpentry

We're a member of the Timber Framers Guild

Timber Framers Guild

American College of the Building Arts, carpentry and timber framing programs.

American College of the Building Arts

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