TIMBER FRAMING DESIGN

Multiplier Table

Pitch°
Rafter
Hip
Rise
Short
10
1.01543
1.42516
0.17633
0.60926
11
1.01872
1.42751
0.19438
0.61123
12
1.02234
1.43010
0.21256
0.61340
13
1.02630
1.43293
0.23087
0.61578
14
1.03061
1.43602
0.24933
0.61837
15
1.03528
1.43937
0.26795
0.62117
16
1.04030
1.44299
0.28675
0.62418
17
1.04569
1.44688
0.30573
0.62742
18
1.05146
1.45106
0.32492
0.63088
19
1.05762
1.45553
0.34433
0.63457
20
1.06418
1.46030
0.36397
0.63851
21
1.07114
1.46538
0.38386
0.64269
22
1.07853
1.47079
0.40403
0.64712
23
1.08636
1.47654
0.42447
0.65182
24
1.09464
1.48264
0.44523
0.65678
25
1.10338
1.48911
0.46631
0.66203
26
1.11260
1.49596
0.48773
0.66756
27
1.12233
1.50320
0.50953
0.67340
28
1.13257
1.51087
0.53171
0.67954
29
1.14335
1.51897
0.55431
0.68601
30
1.15470
1.52753
0.57735
0.69282
31
1.16663
1.53657
0.60086
0.69998
32
1.17918
1.54611
0.62487
0.70751
33
1.19236
1.55619
0.64941
0.71542
34
1.20622
1.56683
0.67451
0.72373
35
1.22077
1.57807
0.70021
0.73246
36
1.23607
1.58993
0.72654
0.74164
37
1.25214
1.60245
0.75355
0.75128
38
1.26902
1.61568
0.78129
0.76141
39
1.28676
1.62965
0.80978
0.77206
40
1.30541
1.64441
0.83910
0.78324

Students should use the sin, cos and tan funtion rather then the Multiplier Table to calculate the length of the roof members. Remember practice makes perfect; it takes some time to get use to these functions.

The more you practise the more familiar you become using these functions

Click here for further trigonometry information.