1. Estimating Hip Roofs

2. Estimating Hip Roofs- Rafters
Pitch = 24⁰
Note – Change of Layout of Ceiling Joists to Accommodate Creepers
Determine No of Rafters
12 500/ 600 = =
= 22 Rafters each side
= 44

3. Determine Rafter Length
Span = 6900

4. Determine Rafter Length
Span = 6900
Half Span = 3450

5. 3450 Determine Rafter Length Span = 6900 Half Span = 3450
Plan Length = 3450
3450

6. 3450 Determine Rafter Length Span = 6900 Half Span = 3450
Plan Length = 3450
Pitch = 24°
3450

7. Determine 1m triangle Hip Length per 1m of Rafter Rafter Length/m
Rise/m
24°
1.000
Plan Length per 1m of Rafter

8. Determine 1m triangle Solve Common Rafter Hip Length per 1m of Rafter
1.000 ÷ Cos 24°
Hip Length per 1m of Rafter
1.000 x Tan 24°
24°
1.000
Plan Length per 1m of Rafter

9. Determine 1m triangle
Solve Common Rafter
1.094
0.455
1.000

10. Determine 1m triangle Solve Hip Hip Length per 1m of Rafter 1.094
0.455
24°
1.000
Plan Length per 1m of Rafter

11. Determine 1m triangle
Solve Hip
1.094
√(2 + Rise2)
0.455
24°
1.000 √2

12. Determine 1m triangle Multipliers 1.094 1.486 0.455 1.000 1.414
This is the multiplier for the Hip Rafter
This is the multiplier for the Common Rafter
1.094
1.486
0.455
24°
1.000
1.414

13. Determine 1m triangle Multipliers 1.094 1.486 0.455 1.000 1.414
This is the multiplier for the Hip Rafter
1.094
1.486
0.455
24°
1.000
1.414

14. Determine Rafter Length Span = 6900 Plan Length = 3450
Rafter Multiplier = 1.094
Hip Multiplier = 1.486
Determine Rafter Length
Span = 6900
Plan Length = 3450

15. Determine Rafter Length Span = 6900 Plan Length = 3450
Rafter Multiplier = 1.094
Hip Multiplier = 1.486
Determine Rafter Length
Span = 6900
Plan Length = 3450
Plan length Eaves = 600

16. Determine Rafter Length Span = 6900 Plan Length = 3450
Rafter Multiplier = 1.094
Hip Multiplier = 1.486
Determine Rafter Length
Span = 6900
Plan Length = 3450
Plan length Eaves = 600
Total Plan Length = 4050

17. Determine Rafter Length Span = 6900 Plan Length = 3450
Rafter Multiplier = 1.094
Hip Multiplier = 1.486
Determine Rafter Length
Span = 6900
Plan Length = 3450
Plan length Eaves = 600
Total Plan Length = 4050
Rafter Length = 4050 x

18. Determine Rafter Length Span = 6900 Plan Length = 3450
Rafter Multiplier = 1.094
Hip Multiplier = 1.486
Rafter 90 x 45
Determine Rafter Length
Span = 6900
Plan Length = 3450
Plan length Eaves = 600
Total Plan Length = 4050
Rafter Length = 4050 x
= Plumb Cut
100 if < 100 else Rafter Depth

19. Determine Rafter Length Span = 6900 Plan Length = 3450
Rafter Multiplier = 1.094
Hip Multiplier = 1.486
Rafter 90 x 45
Determine Rafter Length
Span = 6900
Plan Length = 3450
Plan length Eaves = 600
Total Plan Length = 4050
Rafter Length = 4050 x =
100 if < 100 else Rafter Depth

20. Determine Rafter Length Span = 6900 Plan Length = 3450
Rafter Multiplier = 1.094
Hip Multiplier = 1.486
Rafter 90 x 45
Determine Rafter Length
Span = 6900
Plan Length = 3450
Plan length Eaves = 600
Total Plan Length = 4050
Rafter Length = 4050 x
= 4533

21. Estimating Sheet

22. Estimating Hip Roof - Ridge
Pitch = 24⁰
Overhang 450
Rafter 90 x 45 F7
600 c to c
Ridge 140 x 19
Purlin 90 x 70 F7
Ridge Runs Between Crown End
x 3450 = 5600
½ Rafter Thickness for each hip end
=5645 mm

23. Estimating Sheet

24. Estimating Hip Roof – Hip Rafter

25. Determine Rafter Length Span = 6900 Plan Length = 3450
Rafter Multiplier = 1.094
Hip Multiplier = 1.486
Rafter 90 x 45
Hip 140 x 19
Determine Rafter Length
Span = 6900
Plan Length = 3450
Plan length Eaves = 600
Total Plan Length = 4050
Hip Length = 4050 x

26. Determine Rafter Length Span = 6900 Plan Length = 3450
Rafter Multiplier = 1.094
Hip Multiplier = 1.486
Rafter 90 x 45
Hip 140 x 19
Determine Rafter Length
Span = 6900
Plan Length = 3450
Plan length Eaves = 600
Total Plan Length = 4050
Hip Length = 4050 x
= Hip Depth

27. Determine Rafter Length Span = 6900 Plan Length = 3450
Rafter Multiplier = 1.094
Hip Multiplier = 1.486
Rafter 90 x 45
Hip 140 x 19
Determine Rafter Length
Span = 6900
Plan Length = 3450
Plan length Eaves = 600
Total Plan Length = 4050
Hip Length = 4050 x =

28. Determine Rafter Length Span = 6900 Plan Length = 3450
Rafter Multiplier = 1.094
Hip Multiplier = 1.486
Rafter 90 x 45
Hip 140 x 19
Determine Rafter Length
Span = 6900
Plan Length = 3450
Plan length Eaves = 600
Total Plan Length = 4050
Hip Length = 4050 x
= 6158

29. Estimating Sheet

30. Estimating Hip Roof - Purlin
Pitch = 24⁰
Overhang 450
Rafter 90 x 45 F7
600 c to c
Tiled Roof
Ridge 140 x 19
Purlin 90 x 70 F7
Spacing 2200 centres
1 Row Purlins at Centre Span
Deduct ¼ span for every hip
12500 – 2 x = 9050 allow 150 for joints = 9200
6900 – 2 x 1725 = 3450

31. Estimating Sheet

32. Estimating Hip Roof - Struts
Pitch = 24⁰
Overhang 600
Rafter 90 x 45 F7
600 c to c
Tiled Roof with Flush Gable & Raking Eaves
Ridge 140 x 19
Purlin 90 x 70 F7
Span 2700
Struts are Difficult to Estimate
Develop a Best Guest Method
Determine No Required
9.050/2700 =3.4= 4= 5 Each Side
Determine No Required
3.450/2700 =1.28= 2= 3 Each Side

34. Estimating Gable Roof - Struts
Pitch = 24⁰
Overhang 600
Rafter 90 x 45 F7
600 c to c
Tiled Roof with Flush Gable & Raking Eaves
Ridge 140 x 19
Purlin 90 x 70 F7
Span 2700
Length = Use Rise
Rise = ½ Span x Rise/m
= 3450 x 0.455
= 1.569

35. Estimating Sheet

36. Estimating Gable Roof – Collar Ties
Pitch = 24⁰
Overhang 600
Rafter 90 x 45 F7
600 c to c
Tiled Roof with Flush Gable & Raking Eaves
Ridge 140 x 19
Purlin 90 x 70 F7
Span 2700
Collar Ties 90 x 35
Collar Ties on Every 2nd Rafter
On top of Purlins
Length of Ridge / Rafter Spacing / 2
22/2 = HALF SPAN
3450

37. Estimating Sheet

38. Estimating Tile Quantities
Pitch = 24⁰
Overhang 450
Rafter 90 x 45 F7
600 c to c
Tiled Roof with Flush Gable & Raking Eaves
Ridge 140 x 19
Purlin 90 x 70 F7
Span 2700
Collar Ties 90 x 35
Tiles 7 per m2
True Length of Rafter = 4433
Total Length of Building = x 450 =
Area of Roof = 4433 x 13.7 x 2
= m2 x 7 tiles per m2
= say 851

39. Estimating Sheet