## Saturday, September 29, 2012

### Calculate Irregular Hip Rafter Angles

Here's a couple of screen shots of the Rafter Tools for Anfroid App showing the Calculate Irregular Hip Rafters function. Hopefully, it's Erik proof.

Input variables

1. Roof Eave Angle
2. Major Pitch Angle
3. Minor Pitch Angle
4. Input Length
5. Overhang Run
6. Jack Rafter Spacing
7. Hip Rafter Width
8. Hip Rafter Depth
9. Jack Rafter Width -- Common Rafter Width
10. Major Rafter Depth
11. Seat Cut Level Cut Length
12. Ridge Width
For Input Length use any part of the hip rafter geometry as input to find the rest of the angles.
• Common Rafter Run
• Common Rafter Span
• Common Rafter Rise
• Common Rafter Length
• Hip Rafter Run
• Hip Rafter Length
• Eave Wall Length -- Minor Run
Calculated Results for the Irregular Hip Rafters function.

1. Major Plan Angle
2. Major Roof Pitch Angle
3. Major Roof Pitch
4. Minor Plan Angle
5. Minor Roof Pitch Angle
6. Minor Roof Pitch
7. Major Rafter Run
8. Major Theoretical Rafter Length
9. Major Rafter Length To Ridge
10. Major Rafter Seatcut Length
11. Major Overhang Rafter Length
12. Minor Rafter Run
13. Minor Theoretical Rafter Length
14. Minor Rafter Length To Ridge
15. Minor Rafter Seatcut Length
16. Minor Overhang Rafter Length
17. Hip Rafter Angle
18. Hip Rafter Pitch
19. Hip Rafter Run
20. Hip Rafter Theoretical Rafter Length
21. Hip Rafter Length plumb to plumb along the center line to the ridge.
22. Hip Rafter Long Point Length to Ridge -- long point of hip rafter sidecut
23. Saw Blade Bevel Angle to cut the hip rafter sidecut angle along the hip rafter peak plumb line.
24. Hip Rafter Overhang Length
25. Major Hip Rafter Plumb Backing Mark Height
26. Minor Hip Rafter Plumb Backing Mark Height
27. Major Hip Rafter Perpendicular Backing Mark Height
28. Minor Hip Rafter Perpendicular Backing Mark Height
29. Major Pitch First Jack Rafter Length To Long point of miter cut.
30. Major Pitch Jack Rafter Length Difference @ jack rafter spacing
31. Major Pitch Jack Rafter Saw Blade Bevel Angle
32. Minor Pitch First Jack Rafter Length To Long point of miter cut.
33. Minor Pitch Jack Rafter Length Difference @ jack rafter spacing
34. Minor Pitch Jack Rafter Saw Blade Bevel Angle
35. Theoretical Common Rafte Rise
36. Rise To Top Of Ridge
37. HAP -- Height Above Plate (Heel Height)
38. Major Rafter Plumb Cut Height
39. Minor Rafter Plumb Cut Height
40. Hip Rafter Plumb Cut Height
41. Hip Rafter Drop For Roof Plane Alignment
42. Hip Rafter Backing Offset Main Perpendicular to hip rafter run line.
43. Hip Rafter Backing Offset Adjacent Perpendicular to hip rafter run line.
44. Hip Rafter Backing Offset Main along eave line.
45. Hip Rafter Backing Offset Adjacent along eave line.
46. Hip Rafter Backing Angles
47. Hip Rafter Plumb Backing Angle
48. Hip Rafter Side Cut Angles
49. Jack Rafter Side Cut Angles
50. Roof Sheathing Angles
51. Hip Rafter Purlin Housing Angles
52. Hip Rafter Diamond Post Miter & Saw Blade Bevel Angles
53. Plywood Roof Sheathing Offset Cut Line
54. Valley Sleeper Miter & Saw Blade Bevel Angles
55. Dormer Square Tail Miter & Saw Blade Bevel Angles
56. Purlin Rafter Miter & Saw Blade Bevel Angles
57. Purlin Layover cut perpendicular to roof surface plane