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Major Roof Pitch |
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Minor Roof Pitch |
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Major Plan Angle
atan(minor/major)
angle in plan on the steeper side. | | working with the example of the 8/12, 10/12
8/10 =.8 , arc tan .8= 38.659 degrees
= plan angle of 10/12 side
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Minor Plan Angle
atan(major/minor)
angle in plan
of the shallower-pitched roof. |
| 51.34 degrees = plan angle of 8/12 side |
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Hip Run per Foot | | 8x10 divide 12= 6.666 =rise
8 divide 10 =.8 , arc tan .8 =38.65 degrees
cos 1x 38.659 = 1.2806
1.2806 x
10 =12.806 = hip run for 8-10 runs |
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Angle of Hip | | 6.666 divide 12.806 =.5205
arc tan .5205 =27.498 degrees
= angle of hip
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Backing Angle Shallow Side of Hip | | sine 27.498 = .4617= rise of backing angles
tan 51.34 degrees = 1.2499
.4617 divide 1.2499 = .369
arc tan .369 =20.27
degrees
= saw backing bevel for 8/12 side of hip
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Backing Angle Steep side of Hip | | tan 38.659 = .799 , .4617 divide .799= .577
arc tan .577 =29.99 degrees
= saw backing bevel of 10/12 side of hip. |