ºÝºÝߣ

ºÝºÝߣShare a Scribd company logo

CPCCCA3009A Construct Advanced Roofs Oblique roof

?Download as PPT, PDF?
?
J
jbusse

This document discusses how to calculate angles and position structural members for an oblique end roof where the external walls are parallel. It states that for such roofs, the hips will always bisect the corners at 90 degrees. It provides steps to calculate the angle of the centering rafters based on the wall lengths and roof span. It also explains that the crown end rafter position and length can be determined using similar triangles, with the crown end run being half the roof span and having the same rise as the common rafters.

1 of 70
Downloaded 40 times
Oblique End & Skew End Roof
Solve Angles x and y Walls are parallel
Solve Angles x and y Walls are parallel Determine relevant triangle
Solve Angles x and y Walls are parallel Tan y = Opp/ Adj Tan y = 2000 / 900
Solve Angles x and y Walls are parallel Tan y = 2.222 Angle y = 65.8 ?
Solve Angles x and y Walls are parallel Angle Z =180 ¨C 90 - 65.8 ?
Solve Angles x and y Walls are parallel Angle Z = 24.2 ?
Solve Angles x and y Walls are parallel Angle X = 24.2? + 90?
Solve Angles x and y Walls are parallel Angle X = 114.2?
Oblique End Roof
Determine Position of Centring Rafters
Position Centring Rafter If we extend ridge (which is central) it will intersect with centre of splay end
Positioning Centring Rafter Two Similar Triangles will be formed, 1 half the size of the other
Positioning Centring Rafter Remember for later Therefore we can say the ridge extension length is half the length of the splay end extension
Position Centring Rafters Remember Hips MUST Bisect Corners
Position Centring Rafters Remember Hips MUST Bisect Corners (Angles will vary)
Positioning Centring Rafter x 90? x Corner is Bisected this must also = x
Positioning Centring Rafter x 90? x To form Triangle ? = 180 ¨C 90 ¨C x ? = 90 - x ?
Positioning Centring Rafter x 90? x Hip is at 90? to Centring Rafters 90? - x
Positioning Centring Rafter x 90? x ? = 90? ¨C 90? - x 90? - x ??
Positioning Centring Rafter x 90? x ? = x 90? - x ??
Positioning Centring Rafter x 90? x To form triangle ? =180? - x ¨C x = 180? - 2x 90? - x x ?
Positioning Centring Rafter x 90? x If the angles formed by a T intersection must total 180? ? =180 ? - (180? - 2x) = 2x 90? - x x 180? - 2x ?
Positioning Centring Rafter x 90? x Centring Rafters are at 90? to Ridge & Wall Plates 90? - x x 180? - 2x 2x
Positioning Centring Rafter x 90? x The internal angles of a 4 Sided polygon must total 360? 90? - x x 180? - 2x 2x
Positioning Centring Rafter 90? x ? = 360? - 90? - 90? - 2x? = 180? -2x 90? - x x 180? - 2x 2x ? x
Positioning Centring Rafter 90? Remember Hips bisect corners 90? - x x 180? - 2x 2x 180? - 2x x x
Positioning Centring Rafter x 90? ? ? = 180? - 2x 2 2 = 90? - x 90? - x x 180? - 2x 2x 180? - 2x ?
Positioning Centring Rafter x 90? 90? - x ? = 180? - 2x 2 2 = 90? - x 90? - x x 180? - 2x 2x 90? - x x
Positioning Centring Rafter x 90? 90? - x Complete the Triangle ? = 180? - 90? - (90? - x) = x 90? - x x 180? - 2x 2x 90? - x x ?
Positioning Centring Rafter x 90? 90? - x Angle between Rafters & Ridge is 90? ? = 90? - x 90? - x x 180? - 2x 2x 90? - x x x ?
Positioning Centring Rafter x 90? 90? - x Angle between Hip Rafters ? = 90? - x + x = 90? 90? - x x 180? - 2x 2x 90? - x x x 90? - x
Positioning Centring Rafter x 90? 90? - x Angle between Hip Rafters = 90? 90? - x x 180? - 2x 2x 90? - x x x 90? - x
Positioning Centring Rafter x 90? -x 90? x 90 90? - x x 90? Therefore we can say When the corners of a splayed end roof are bisected they will intersect at the ridge The angles formed by the hips will be 90?
Positioning Centring Rafter If we centre a circle on the intersection of the Ridge & skew end Then make the diameter the length Of the skew end The circle will pass thru the corners = =
Positioning Centring Rafter Lines from each end of a diameter that intersect on the circumference of the Circle will intersect at 90 ? = =
Positioning Centring Rafter If we extend lines from these intersections To the centre of the circle = =
Positioning Centring Rafter If we extend lines from these intersections To the centre of the circle They must be radiuses = =
Positioning Centring Rafter The ridge line extended past the centring Rafter must be a radius of this circle
Positioning Centring Rafter The Ridge Extension must equal the half length of the Splay end = = =
Positioning Centring Rafter = = =
Positioning Centring Rafter Previously we determined that the length of The ridge extension was half the splay end extension = = =
Positioning Centring Rafter Therefore the offset must equal Radius ¨C Half Splay Extension = = =
Positioning Centring Rafter Better we can say Half Splay End Length ¨C Half Splay Extension 1097 ¨C 450 = 647
Positioning Centring Rafter x 90? -x 90? x 90 90? - x x 90? Therefore we can say If External walls are parallel Hips always bisect corners When the corners of a splayed end roof are bisected they will intersect at the ridge The angles formed by the hips will be 90? (This is the same for a conventional roof)
Solve Angle y Developing from last week x 90? 90 90? - x x y
Solve Angle y Developing from last week x 90? 90 90? - x x Hips Always Bisect Corners y x 90? - x
Solve Angle y Developing from last week x 90? 90 90? - x x Hips Always Bisect Corners Rafters are always at 90¡ã to wall plates y x 90?
Solve y Developing from last week x 90? 90 90? - x x Hips Always Bisect Corners Rafters are always at 90¡ã to wall plates 90 -x x 90? This angle must = 90 - x
Solve Crown End Run x 90? 90 90? - x 90- x x 90?
Solve Crown End Run x 90? 90 90? - x 90- x 90- x This angle must be 90 - x x 90?
Solve Crown End Run x 90? 90 90? - x 90- x 90- x The angles in both these triangles are the same x 90? 90?
Solve Crown End Run x 90? 90 90? - x 90- x 90- x Therefore these triangles are similar triangles x 90? 90?
Solve Crown End Run x 90? 90 90? - x 90- x 90- x The Hypotenuse of these triangles are the same x 90? 90?
Solve Crown End Run x 90? 90 90? - x 90- x 90- x The triangles are equal triangles So all sides will be equal x 90? 90?
Solve Crown End Run x 90? 90 90? - x 90- x 90- x Crown End Run = Half Span x 90? 90?
Solve Crown End Run x 90? 90 90? - x 90- x 90- x Crown End Run = Half Span Crown End Rafter position will Equal same distance as Centring Rafters from the short end x 90? 90?
Gathering Point Similar to a conventional hip roof the gathering point is at the centreline of the Ridge & Centring rafters
Gathering Point Similar to a conventional hip roof the gathering point is at the centreline of the Ridge & Centring rafters
Gathering Point Similar to conventional hip roof all members that form the oblique end hip have the same rise as the common rafters
Crown End Rafter Centreline Length Similar to a conventional hip roof The Crown End Rafters Centreline Run is the same as the common rafters
Crown End Rafter Centreline Length Similar to a conventional hip roof The Crown End Rafters Centreline Rise is the same as the Common Rafters The Crown End Rafters Centreline Run is the same as the Common Rafters
Crown End Rafter Centreline Length The Centreline Line (CL) Length can be calculated in the same way Crown CL = CL Run ¡Â Cos Pitch Crown CL = 1000 ¡Â Cos 25 ? Crown CL =1000 ¡Â 0.906 Crown CL =1.103 Pitch 25 ?
Crown End Rafter Centreline Length The Centreline Line (CL) Length can be calculated in the same way Crown CL = CL Run ¡Â Cos Pitch Crown CL = 1000 ¡Â Cos 25 ? Crown CL =1000 ¡Â 0.906 Crown CL =1.103 (Note that this length also represents the length per metre Pitch 25 ?
Crown End Rafter Centreline Length using Pythagoras The Centreline Line (CL) Length can be calculated in the same way Crown CL = ¡Ì(CL Run ? + Rise ?) Crown CL = ¡Ì(1 ? + 0.466 ?) Crown CL = ¡Ì(1 + 0.217 ) = ¡Ì(1.217 ) Crown CL =1.103 Pitch 25 ?
Crown End Rafter Centreline Length using Trigonometry The Centreline Line (CL) Length can be calculated in the same way Crown CL = CL Run ¡Â Cos Pitch Crown CL = 1000 ¡Â Cos 25 ? Crown CL =1000 ¡Â 0.906 Crown CL =1.103 Pitch 25 ?
Crown End Rafter True Length Similar to a conventional hip roof The Crown End Rafters will butt into the Centring Rafters
Crown End Rafter True Length Different to a conventional hip roof The Crown End Rafters do not butt into the Centring Rafters at 90 ?
Crown End Rafter True Length The Centreline Line (CL) Length can be calculated in the same way Crown CL = CL Run ¡Â Cos Pitch Crown CL = 1000 ¡Â Cos 25 ? Crown CL =1000 ¡Â 0.906 Crown CL =1.103 (Note that this length also represents the length per metre Pitch 25 ?
Crown End Rafter True Length The Centreline Line (CL) Length can be calculated in the same way Crown CL = ¡Ì(CL Run ? + Rise ?) Crown CL = ¡Ì(1 ? + 0.466 ?) Crown CL = ¡Ì(1 + 0.217 ) = ¡Ì(1.217 ) Crown CL =1.103 Pitch 25 ?

More Related Content

CPCCCA3009A Construct Advanced Roofs Oblique roof

  • 1. Oblique End & Skew End Roof
  • 2. Solve Angles x and y Walls are parallel
  • 3. Solve Angles x and y Walls are parallel Determine relevant triangle
  • 4. Solve Angles x and y Walls are parallel Tan y = Opp/ Adj Tan y = 2000 / 900
  • 5. Solve Angles x and y Walls are parallel Tan y = 2.222 Angle y = 65.8 ?
  • 6. Solve Angles x and y Walls are parallel Angle Z =180 ¨C 90 - 65.8 ?
  • 7. Solve Angles x and y Walls are parallel Angle Z = 24.2 ?
  • 8. Solve Angles x and y Walls are parallel Angle X = 24.2? + 90?
  • 9. Solve Angles x and y Walls are parallel Angle X = 114.2?
  • 11. Determine Position of Centring Rafters
  • 12. Position Centring Rafter If we extend ridge (which is central) it will intersect with centre of splay end
  • 13. Positioning Centring Rafter Two Similar Triangles will be formed, 1 half the size of the other
  • 14. Positioning Centring Rafter Remember for later Therefore we can say the ridge extension length is half the length of the splay end extension
  • 15. Position Centring Rafters Remember Hips MUST Bisect Corners
  • 16. Position Centring Rafters Remember Hips MUST Bisect Corners (Angles will vary)
  • 17. Positioning Centring Rafter x 90? x Corner is Bisected this must also = x
  • 18. Positioning Centring Rafter x 90? x To form Triangle ? = 180 ¨C 90 ¨C x ? = 90 - x ?
  • 19. Positioning Centring Rafter x 90? x Hip is at 90? to Centring Rafters 90? - x
  • 20. Positioning Centring Rafter x 90? x ? = 90? ¨C 90? - x 90? - x ??
  • 21. Positioning Centring Rafter x 90? x ? = x 90? - x ??
  • 22. Positioning Centring Rafter x 90? x To form triangle ? =180? - x ¨C x = 180? - 2x 90? - x x ?
  • 23. Positioning Centring Rafter x 90? x If the angles formed by a T intersection must total 180? ? =180 ? - (180? - 2x) = 2x 90? - x x 180? - 2x ?
  • 24. Positioning Centring Rafter x 90? x Centring Rafters are at 90? to Ridge & Wall Plates 90? - x x 180? - 2x 2x
  • 25. Positioning Centring Rafter x 90? x The internal angles of a 4 Sided polygon must total 360? 90? - x x 180? - 2x 2x
  • 26. Positioning Centring Rafter 90? x ? = 360? - 90? - 90? - 2x? = 180? -2x 90? - x x 180? - 2x 2x ? x
  • 27. Positioning Centring Rafter 90? Remember Hips bisect corners 90? - x x 180? - 2x 2x 180? - 2x x x
  • 28. Positioning Centring Rafter x 90? ? ? = 180? - 2x 2 2 = 90? - x 90? - x x 180? - 2x 2x 180? - 2x ?
  • 29. Positioning Centring Rafter x 90? 90? - x ? = 180? - 2x 2 2 = 90? - x 90? - x x 180? - 2x 2x 90? - x x
  • 30. Positioning Centring Rafter x 90? 90? - x Complete the Triangle ? = 180? - 90? - (90? - x) = x 90? - x x 180? - 2x 2x 90? - x x ?
  • 31. Positioning Centring Rafter x 90? 90? - x Angle between Rafters & Ridge is 90? ? = 90? - x 90? - x x 180? - 2x 2x 90? - x x x ?
  • 32. Positioning Centring Rafter x 90? 90? - x Angle between Hip Rafters ? = 90? - x + x = 90? 90? - x x 180? - 2x 2x 90? - x x x 90? - x
  • 33. Positioning Centring Rafter x 90? 90? - x Angle between Hip Rafters = 90? 90? - x x 180? - 2x 2x 90? - x x x 90? - x
  • 34. Positioning Centring Rafter x 90? -x 90? x 90 90? - x x 90? Therefore we can say When the corners of a splayed end roof are bisected they will intersect at the ridge The angles formed by the hips will be 90?
  • 35. Positioning Centring Rafter If we centre a circle on the intersection of the Ridge & skew end Then make the diameter the length Of the skew end The circle will pass thru the corners = =
  • 36. Positioning Centring Rafter Lines from each end of a diameter that intersect on the circumference of the Circle will intersect at 90 ? = =
  • 37. Positioning Centring Rafter If we extend lines from these intersections To the centre of the circle = =
  • 38. Positioning Centring Rafter If we extend lines from these intersections To the centre of the circle They must be radiuses = =
  • 39. Positioning Centring Rafter The ridge line extended past the centring Rafter must be a radius of this circle
  • 40. Positioning Centring Rafter The Ridge Extension must equal the half length of the Splay end = = =
  • 42. Positioning Centring Rafter Previously we determined that the length of The ridge extension was half the splay end extension = = =
  • 43. Positioning Centring Rafter Therefore the offset must equal Radius ¨C Half Splay Extension = = =
  • 44. Positioning Centring Rafter Better we can say Half Splay End Length ¨C Half Splay Extension 1097 ¨C 450 = 647
  • 45. Positioning Centring Rafter x 90? -x 90? x 90 90? - x x 90? Therefore we can say If External walls are parallel Hips always bisect corners When the corners of a splayed end roof are bisected they will intersect at the ridge The angles formed by the hips will be 90? (This is the same for a conventional roof)
  • 46. Solve Angle y Developing from last week x 90? 90 90? - x x y
  • 47. Solve Angle y Developing from last week x 90? 90 90? - x x Hips Always Bisect Corners y x 90? - x
  • 48. Solve Angle y Developing from last week x 90? 90 90? - x x Hips Always Bisect Corners Rafters are always at 90¡ã to wall plates y x 90?
  • 49. Solve y Developing from last week x 90? 90 90? - x x Hips Always Bisect Corners Rafters are always at 90¡ã to wall plates 90 -x x 90? This angle must = 90 - x
  • 50. Solve Crown End Run x 90? 90 90? - x 90- x x 90?
  • 51. Solve Crown End Run x 90? 90 90? - x 90- x 90- x This angle must be 90 - x x 90?
  • 52. Solve Crown End Run x 90? 90 90? - x 90- x 90- x The angles in both these triangles are the same x 90? 90?
  • 53. Solve Crown End Run x 90? 90 90? - x 90- x 90- x Therefore these triangles are similar triangles x 90? 90?
  • 54. Solve Crown End Run x 90? 90 90? - x 90- x 90- x The Hypotenuse of these triangles are the same x 90? 90?
  • 55. Solve Crown End Run x 90? 90 90? - x 90- x 90- x The triangles are equal triangles So all sides will be equal x 90? 90?
  • 56. Solve Crown End Run x 90? 90 90? - x 90- x 90- x Crown End Run = Half Span x 90? 90?
  • 57. Solve Crown End Run x 90? 90 90? - x 90- x 90- x Crown End Run = Half Span Crown End Rafter position will Equal same distance as Centring Rafters from the short end x 90? 90?
  • 58. Gathering Point Similar to a conventional hip roof the gathering point is at the centreline of the Ridge & Centring rafters
  • 59. Gathering Point Similar to a conventional hip roof the gathering point is at the centreline of the Ridge & Centring rafters
  • 60. Gathering Point Similar to conventional hip roof all members that form the oblique end hip have the same rise as the common rafters
  • 61. Crown End Rafter Centreline Length Similar to a conventional hip roof The Crown End Rafters Centreline Run is the same as the common rafters
  • 62. Crown End Rafter Centreline Length Similar to a conventional hip roof The Crown End Rafters Centreline Rise is the same as the Common Rafters The Crown End Rafters Centreline Run is the same as the Common Rafters
  • 63. Crown End Rafter Centreline Length The Centreline Line (CL) Length can be calculated in the same way Crown CL = CL Run ¡Â Cos Pitch Crown CL = 1000 ¡Â Cos 25 ? Crown CL =1000 ¡Â 0.906 Crown CL =1.103 Pitch 25 ?
  • 64. Crown End Rafter Centreline Length The Centreline Line (CL) Length can be calculated in the same way Crown CL = CL Run ¡Â Cos Pitch Crown CL = 1000 ¡Â Cos 25 ? Crown CL =1000 ¡Â 0.906 Crown CL =1.103 (Note that this length also represents the length per metre Pitch 25 ?
  • 65. Crown End Rafter Centreline Length using Pythagoras The Centreline Line (CL) Length can be calculated in the same way Crown CL = ¡Ì(CL Run ? + Rise ?) Crown CL = ¡Ì(1 ? + 0.466 ?) Crown CL = ¡Ì(1 + 0.217 ) = ¡Ì(1.217 ) Crown CL =1.103 Pitch 25 ?
  • 66. Crown End Rafter Centreline Length using Trigonometry The Centreline Line (CL) Length can be calculated in the same way Crown CL = CL Run ¡Â Cos Pitch Crown CL = 1000 ¡Â Cos 25 ? Crown CL =1000 ¡Â 0.906 Crown CL =1.103 Pitch 25 ?
  • 67. Crown End Rafter True Length Similar to a conventional hip roof The Crown End Rafters will butt into the Centring Rafters
  • 68. Crown End Rafter True Length Different to a conventional hip roof The Crown End Rafters do not butt into the Centring Rafters at 90 ?
  • 69. Crown End Rafter True Length The Centreline Line (CL) Length can be calculated in the same way Crown CL = CL Run ¡Â Cos Pitch Crown CL = 1000 ¡Â Cos 25 ? Crown CL =1000 ¡Â 0.906 Crown CL =1.103 (Note that this length also represents the length per metre Pitch 25 ?
  • 70. Crown End Rafter True Length The Centreline Line (CL) Length can be calculated in the same way Crown CL = ¡Ì(CL Run ? + Rise ?) Crown CL = ¡Ì(1 ? + 0.466 ?) Crown CL = ¡Ì(1 + 0.217 ) = ¡Ì(1.217 ) Crown CL =1.103 Pitch 25 ?