Dormer Shed Roof, Barrel Roof, CutIn Dormer, Eyebrow Dormer

sbebuilders

We've been out of work this last month, so to to keep busy I wrote the following online scripts.

Dormer Shed Roof Rafter Calculator
http://sbebuilders.com/tools/geometr..._shed_roof.php

This Dormer Shed Roof calculator will return roof framing trigonometry & geometry details for:

Dormer Shed Roof Rafter Length
Dormer Shed Roof Miter Angle (Rake Cut Angle)
Dormer Shed Roof Sleeper Bevel Length
Dormer Shed Roof Intercept Run ( Intersection of Dormer Roof and Main Roof)
Main Roof Intercept Length (Usefull for laying out Dormer Sleeper that is not Beveled)


CutIn Dormer Shed Roof Rafter Calculator
http://sbebuilders.com/tools/geometr..._shed_roof.php

This CutIn Dormer Shed Roof calculator will return roof framing trigonometry & geometry details for:

Dormer Shed Roof Rafter Length
Dormer Shed Roof Miter Angle (Rake Cut Angle)
Dormer Shed Roof Run
Main Roof Rafter Intercept Length
Dormer Intersect Length For Lapping Rafters
Intersecting Roof Slope Angle

Pitch Break Shed Roof Rafter Calculator
http://sbebuilders.com/tools/geometr..._shed_roof.php

This Pitch Break Shed Roof calculator will return roof framing trigonometry & geometry details for:

Pitch Break Shed Roof Rafter Length
Pitch Break Shed Roof Miter Angle (Rake Cut Angle)
Total Pitch Break Run ( Intersection of Shed Roof and Main Roof)
Main Roof Intercept Length
Main Roof Run To Intersection of Main Roof And Shed Roof

Barrel Roof Dormer Framing Calculator
http://www.sbebuilders.com/tools/geo...arrel_roof.php

This Barrel Roof Dormer calculator will return roof framing trigonometry & geometry details for:

Barrel Roof Semi Major Axis of the Elliptical Valley Footprint
Barrel Roof Plan View Run of the Ellipse from the intersection of the barrel roof and main roof.
Total Arc Length of Barrel Roof
Arc Angle of Purlin Rafter Spacing
Cord Length of Purlin Rafter Spacing
Ellipse layout points on Main Roof Surface
Purlin Rafters cut perpendicular to Roof Surface
Purlin Rafter Slope Angle
Purlin Rafter Miter Angle
Purlin Rafter Saw Blade Bevel Angle
Barrel Roof Plan View Rafter Lengths
X & Y Points for Elliptical Ploting of the Ellipse on the Main Roof Surface
Real Roof Surface plotting points for the plywood roof sheathing
Ellipse Valley Sleeper Offset
Purlin Rafter Deduction for Ellipse Valley Sleeper Offset

Eyebrow Roof Dormer Framing Calculator
http://www.sbebuilders.com/tools/geo...oof_dormer.php

This Eyebrow Roof Dormer calculator will return roof framing trigonometry & geometry details for:

Eyebrow Roof Dormer Semi Major Axis of the Elliptical Valley Footprint
Eyebrow Roof Dormer Plan View Run of the Ellipse from the intersection of the eyebrow roof and main roof.
Total Arc Length of Eyebrow Roof Dormer
Arc Angle of Purlin Rafter Spacing
Cord Length of Purlin Rafter Spacing
Ellipse layout points on Main Roof Surface
Purlin Rafters cut perpendicular to Roof Surface
Purlin Rafter Slope Angle
Purlin Rafter Miter Angle
Purlin Rafter Saw Blade Bevel Angle
Eyebrow Roof Dormer Plan View Rafter Lengths
X & Y Points for Elliptical Ploting of the Ellipse on the Main Roof Surface
Real Roof Surface plotting points for the plywood roof sheathing
Ellipse Valley Sleeper Offset
Purlin Rafter Deduction for Ellipse Valley Sleeper Offset

Sim

Attached Thumbnails

 

sbebuilders

The Eyebrow Roof Dormer Framing Calculator is based on two tangent circles with the same radius. The script takes the total arc length of the eyebrow roof dormer face profile and divides it by the O.C. spacing of the purlin rafters to calculate the layout points on the plan view ellipse and the roof surface ellipse. It then uses these points to draw out an AutoCAD DXF file each time the script is run. You can download and view the DXF file in any CAD program. The script also draws the real roof surface of the eyebrow roof dormer (roof sheathing).

You can also import the DXF file into Google SketchUp and connect the plan view ellipse, main roof surface ellipse rotated to the slope angle of the roof and the eyebrow dormer face profile. Then connect the lines for a 3D image of the Eyebrow Roof Dormer.

An Google SketchUp model of the eyebrow dormer created from the DXF is attached below.

Sim

Attached Thumbnails

       

Attached Files

Eyebrow_Roof_Dormer_2.skp (32.6 KB, 46 views)

sbebuilders

The Barrel Roof Dormer Framing Calculator is based on a right cylinder intersecting with a sloping surface. The script takes the total arc length of the barrel roof dormer face profile and divides it by the O.C. spacing of the purlin rafters to calculate the layout points on the plan view ellipse and the roof surface ellipse. It then uses these points to draw out an AutoCAD DXF file each time the script is run. You can download and view the DXF file in any CAD program. The script also draws the real roof surface of the barrel roof dormer (roof sheathing).

You can also import the DXF file into Google SketchUp and connect the plan view ellipse, main roof surface ellipse rotated to the slope angle of the roof and the barrel dormer face profile. Then connect the lines for a 3D image of the Barrel Roof Dormer.

A Google SketchUp model of the barrel roof dormer created from the DXF file is attached below.

Sim

Attached Thumbnails

     

Attached Files

Barrel_Roof_Wireframe.skp (34.6 KB, 36 views)

sbebuilders

The Dormer Shed Roof Rafter Calculator prints out something like like.

Dormer Shed Roof Calculations
Calculations are rounded to the nearest 1/16 inch


Main Roof Pitch = 8:12
Main Roof Pitch Angle = 33.69007°
Main Rafter HAP = 0'-7 13/16''
Main Roof Sheathing Thickness = 0'-0 1/2''
Main Roof Rafter Material Depth = 0'-9 1/2''
Main Roof Rafter Plumb Height = 0'-11 7/16''
Main Run = 2'-8 9/16''

Dormer & Main Roof Plate Line Difference = 0'-0''

Dormer Roof Pitch = 3:12
Dormer Roof Pitch Angle = 14.03624°
Dormer Rafter HAP = 0'-8 7/16''
Dormer Run = 4'-6''
Dormer Sleeper Material Thickness = 0'-1 1/2''
Dormer Roof Rafter Material Depth = 0'-9 1/2''
Dormer Roof Rafter Plumb Height = 0'-9 13/16''
Dormer Rafter Length = 7'-0 13/16''
Dormer Sleeper Bevel Length = 0'-4 1/2''
Dormer Miter Cut Angle = 19.65382°
Dormer Rafter Miter Cut Length = 2'-4 1/4''
Dormer Intercept Run = 7'-2 9/16''

Main Roof Slope Intercept Length = 2'-10 15/16''
Dormer Rafter Length To Main Roof Sheathing Without Sleeper = 7'-5 1/4''

C1 = 75.96376°
C2 = 70.34618°
C = 146.30993°
A = 19.65382°
a = 54.00000



Using the Law of Sines
c = ( a × sin( C ) ) ÷ sin( A)

c = Dormer Rafter Length
A = Main Roof Pitch Angle - Dormer Roof Pitch Angle
C = 90° - Dormer Roof Pitch Angle + (90° - (Main Roof Pitch Angle - Dormer Roof Pitch Angle))


Dormer Rafter Length = Dormer Run × sin(90° - Dormer Roof Pitch Angle + ( 90° - (Main Roof Pitch Angle - Dormer Roof Pitch Angle))) ÷ sin(Main Roof Pitch Angle - Dormer Roof Pitch Angle))
Dormer Rafter Length = 54.00 × sin(90° - 33.69007° + (90° - (33.69007° - 14.03624°))) ÷ sin(33.69007° - 14.03624° )
Dormer Rafter Length = 54.00 × sin(146.30993) ÷ sin(19.65382 )= 89.05908

or
Dormer Altitude = sin(Dormer Roof Pitch Angle) * Dormer Run
Dormer Altitude Run = Dormer Altitude ÷ tan(Dormer Roof Pitch Angle)
Dormer Miter Cut Angle = Main Roof Pitch Angle - Dormer Roof Pitch Angle
Main Altitude Run = Dormer Altitude ÷ tan(Dormer Miter Cut Angle)
Dormer Rafter Length = Dormer Altitude Run + Main Altitude Run
Main Intercept Run = (Dormer Rafter Length * cos( Dormer Roof Pitch Angle)) - Dormer Run


Dormer Altitude = 1'-1 1/8''
Dormer Altitude Run = 4'-4 1/2''
Dormer Miter Cut Angle = 19.65382°
Main Altitude Run = 3'-0 3/4''

Dormer Rafter Length To Main Roof Sheathing Without Sleeper = 7'-5 1/4''
Main Intercept Run = 2'-8 1/2''

Attached Thumbnails

       

sbebuilders

The CutIn Dormer Shed Roof Rafter Calculator prints out something like this.

CutIn Dormer Shed Roof Calculations
Calculations are rounded to the nearest 1/16 inch


Main Roof Pitch = 8:12
Main Roof Pitch Angle = 33.69007°
Main Roof Rafter Material Depth = 0'-9 1/2''
Main Roof Rafter Plumb Height = 0'-11 7/16''

Dormer Plate Line Height Above Main Roof = 3'-0''

Dormer Roof Pitch = 3:12
Dormer Roof Pitch Angle = 14.03624°
Dormer Rafter HAP = 0'-6 7/8''
Dormer Run = 8'-6 7/8''
Dormer Roof Rafter Material Depth = 0'-7 1/2''
Dormer Roof Rafter Plumb Height = 0'-7 3/4''
Dormer Rafter Length = 8'-10 1/16''
Dormer Miter Cut Angle = 19.65382°
Dormer Rafter Miter Cut Length = 2'-4 1/4''

Main Roof Rafter Intercept Length = 10'-3 5/8''
Intersecting Roof Slope Angle = 22.61986°

Attached Thumbnails

     

sbebuilders

The Pitch Break Shed Roof Rafter Calculator prints out something like this.

Pitch Break Shed Roof Calculations
Calculations are rounded to the nearest 1/16 inch


Main Roof Pitch = 8:12
Main Roof Pitch Angle = 33.69007°
Main Rafter HAP = 0'-7 13/16''
Main Roof Rafter Material Depth = 0'-9 1/2''
Main Roof Rafter Plumb Height = 0'-11 7/16''
Main Pitch Run = 8'-1 5/16''

Shed Roof Plate Line Difference = 0'-0''

Shed Roof Pitch = 4:12
Shed Roof Pitch Angle = 18.43495°
Shed Rafter HAP = 0'-8 3/16''
Shed Roof Run = 8'-0''
Shed Roof Rafter Material Depth = 0'-9 1/2''
Shed Roof Rafter Plumb Height = 0'-10 1/16''
Shed Roof Rafter Length = 16'-11 3/4''

Intersect Miter Cut Angle = 15.25512°
Intersect Miter Cut Length = 3'-0 1/8''

Total Pitch Break Run = 16'-1 5/16''

Main Roof Intercept Length = 9'-8 15/16''

Attached Thumbnails

   

Ninjaframer

That's pretty cool. I only understand the shed roof one though law of sines!

__________________
"slow makes smooth, smooth makes fast"

mike86

This should have generated much more comments,Its great to see some one put this level of effort into this roof.

I was able to build a model but the way in which I figured it was tedious and not practical for a full scale roof.

Thanks for this.

dave_dj1

I agree ^, this is the first time I've seen this thread. You did a great thing!
I've built eyebrow windows before and I could have used your information.
Keep up the great work and hopefully you will get back to work soon

jb4211

This should be a sticky; my first time seeing this thread as well.

__________________
"The man who says it can't be done, shouldn't interrupt the man doing it."
Jon

The man who will use his skill and constructive imagination to see how much he can give for a dollar instead of how little he can give for a dollar is bound to succeed. Henry Ford

skillman

Time well spent and very informative . Great job

TimelessQuality

I'll second that

Great work Sim... Thanks for sharing it

__________________
-Steve

'The more you explain it, the more I don't understand it.' - Mark Twain

CanningCustom

Incredible break down Sim, very much appreciated. Some one please "sticky" this!

mike86

I agree,

This is the first time I've seen anybody breakdown the eyebrow dormer mathematically,I was able to calculate the front and the remaining ribs of the roof,but it required so much math I didn't even want to mess with the elliptical sleeper boards.

jb4211

really nice that someone shares their efforts, and there's definitely a lot of effort into those designs.

__________________
"The man who says it can't be done, shouldn't interrupt the man doing it."
Jon

The man who will use his skill and constructive imagination to see how much he can give for a dollar instead of how little he can give for a dollar is bound to succeed. Henry Ford

VinylHanger

Thanks a bunch. It is nice to see folks sharing knowledge.

__________________
Your emergency does not constitute a problem with my Constitution.

Sampietro

Great info I am sure it will be very helpful. Thanks for taking the time to post!!

sbebuilders

Thanks for the comments.

Here's a link to a Google Sketchup plugin I just wrote. It draws outs roof framing tetrahedrons and roof framing kernels.


http://www.sbebuilders.com/pdf/RoofFraming.zip

Just unzip it in the Google SketchUp \Plugins directory.
The file structure should look something like this.

C:\Program Files\Google\Google SketchUp 8\Plugins\RoofFraming.rb
C:\Program Files\Google\Google SketchUp 8\Plugins\RoofFraming\plan_angle.rb
C:\Program Files\Google\Google SketchUp 8\Plugins\RoofFraming\draw_angle_dim.rb
C:\Program Files\Google\Google SketchUp 8\Plugins\RoofFraming\interior.png
C:\Program Files\Google\Google SketchUp 8\Plugins\RoofFraming\exterior.png

Sim

Attached Thumbnails

       

mike86

Every carpenter should understand tetrahedron and how to solve for formula,they would throw away every roof framing book they ever purchased.

mike86

What language did you use to program it?