This section is from the book "Building Construction And Superintendence", by F. E. Kidder. Also available from Amazon: Building Construction And Superintendence.
A. Shingled Roofs Not Plastered.*
Total load, 48 pounds per square foot.
Size of Joists. | Dist. on Centres. | Hemlock. | White Pine. | Spruce or Norway Pine. | Oregon or Texas Pine. | Georgia Pine. | |||||
Ins. | Ft. | Ins. | Ft. | Ins. | Ft. | Ins. | Ft. | Ins. | Ft. | Ins. | |
2x4 | 16 | 7 | 4 | 7 | 9 | 8 | 4 | 9 | 6 | 10 | 10 |
2x4 | 20 | 6 | 7 | 6 | 10 | 7 | 6 | 8 | 6 | 8 | 10 |
2x6 | 16 | 11 | 1 | 11 | 7 | 12 | 6 | 14 | 2 | 15 | 0 |
2x6 | 20 | 9 | 11 | 10 | 4 | 11 | 2 | 12 | 8 | 13 | 4 |
3x6 | 16 | 13 | 7 | 14 | 2 | 15 | 3 | 17 | 5 | 18 | 3 |
3x6 | 20 | 12 | 2 | 12 | 8 | 13 | 8 | 15 | 7 | 16 | 4 |
2x8 | 16 | 14 | 9 | 15 | 6 | 16 | 8 | 18 | 11 | 20 | 0 |
2x8 | 20 | 13 | 3 | 13 | 10 | 14 | 11 | 16 | 11 | 17 | 10 |
2x8 | 24 | 12 | 1 | 12 | 7 | 13 | 7 | 15 | 6 | 16 | 3 |
2x10 | 16 | 18 | 6 | 19 | 3 | 20 | 10 | 23 | 8 | 25 | 0 |
2x10 | 20 | 16 | 7 | 17 | 3 | 18 | 8 | 21 | 2 | 22 | 3 |
2x10 | 24 | 15 | 1 | 15 | 9 | 17 | 0 | 19 | 3 | 20 | 4 |
B. Slate Roofs Not Plastered, or Shingle Roofs Plastered.*
Total load, 57 pounds per square foot.
Size of Joists. | Dist. on Centres. | Hemlock. | White Pine. | Spruce. | Oregon Pine. | Georgia Pine. | |||||
Ins. | Ft. | Ins. | Ft. | Ins. | Ft. | Ins. | Ft. | Ins. | Ft. | Ins. | |
2x4 | 16 | 6 | 9 | 7 | I | 7 | 7 | 8 | 8 | 9 | 2 |
2x4 | 20 | 6 | 0 | 6 | 4 | 6 | 9 | 7 | 9 | 8 | 2 |
2x6 | 16 | 10 | 2 | 10 | 7 | 11 | 6 | 13 | 0 | 13 | 8 |
2x6 | 20 | 9 | 1 | 9 | 6 | 10 | 2 | 11 | 7 | 12 | 3 |
3x6 | 16 | 12 | 6 | 13 | 0 | 14 | 1 | 15 | 11 | 16 | 9 |
3x6 | 20 | 11 | •1 | 11 | 8 | 12 | 7 | 14 | 3 | 15 | 0 |
2x8 | 16 | 13 | 7 | 14 | 2 | 15 | 3 | 17 | 4 | 18 | 3 |
2x8 | 20 | 12 | 2 | 12 | 8 | 13 | 8 | 15 | 6 | 16 | 4 |
2x8 | 24 | 11 | 1 | II | 7 | 12 | 6 | 14 | 2 | 14 | 11 |
3x8 | 16 | 16 | 7 | 17 | 4 | 18 | 9 | 21 | 3 | 22 | 5 |
3x8 | 20 | 14 | 10 | 15 | 6 | 16 | 9 | 19 | 0 | 20 | 1 |
3x8 | 24 | 13 | 7 | 14 | 2 | 15 | 3 | 17 | 4 | 18 | 4 |
2x10 | 16 | 17 | 0 | 17 | 8 | 19 | 2 | 21 | 7 | 22 | 10 |
2x10 | 20 | 15 | 2 | 15 | 10 | 17 | 1 | 19 | 4 | 20 | 6 |
2x10 | 24 | 13 | 10 | 14 | 6 | 15 | 7 | 17 | 8 | 18 | 8 |
 
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