This section is from the book "Cassell's Cyclopaedia Of Mechanics", by Paul N. Hasluck. Also available from Amazon: Cassell's Cyclopaedia Of Mechanics.
The accompanying table shows at a glance the respective scantlings for collar, king-post, and queen-post roofs. As to the various adaptabilities of these roofs, it may be stated that collar roofs ai'e not adaptable for roofs above 18-ft. span, because the timbers would be abnormally large, the expenditure would be exorbitant, and the roof would be unsightly. King-post roofs are applicable for roofs of 18-ft. to 30-ft. span. Queen-post roofs are applicable for roofs 30-ft. to 45-ft. span.
Description of Roof. | Span. | Tie Beam. | Principal Rafter. | King Post. | Queen Post. | Strut. | Straining Beam. | Purlin. | Straining Sill. | Common Rafter. | Collar. | Ridge. |
Feet. | Inches. | Inches. | Indies. | Inches. | Inches. | Inches. | Inces. | Inches. | Inches. | Inches. | Inches. | |
Collar Roof. | 8 | 3x2 | 2x2 | 7 x 1 1/4 | ||||||||
10 | 31 x 2 | 2 1/2 x 2 | 7 x 1 1/2 | |||||||||
12 | 31/2x 2 1/4 | 3 1/2 x 2 | 7 x 1 1/2 | |||||||||
14 | 4x2 | 4 1/2 x 2 | 9 x 1 1/2 | |||||||||
16 | 4x2 | 5x2 | 9 x 1 1/2 | |||||||||
18 | 4 x 2 1/4 | 5 1/2 x 2 | 9x1 1/2 | |||||||||
King-post Roof. | 18 | 7x3 | 41/2x3 | 4 1/2 x 3 | 3 1/2 x 2 | 7x3 | 3 1/2 x 2 | |||||
20 | 9x4 | 4 x 4 | 5x4 | 4x2 | 7x4 | 4x2 | ||||||
22 | 9x4 | 6x3 | 6 x 3.4 | 4 x 2 1/2 | 8x4 | 4 1/2 x 2 | ||||||
24 | 91/2 x 4 | 6 x 3 1/2 | 6x3 1/2 | 44 x 2 3/4 | 8x5 | 4 1/2 x 2 | ||||||
26 | 9x5 | 6x4 | 6x4 | 4x3 | 8 1/2 x 5 | 4 1/2x 2 1/4 | ||||||
28 | 10 x 5 | 6x4 | 6x6 | 4 1/2 x 3 | 8 3/4 x 5 1/4 | 41/2 x 2 1/3 | ||||||
30 | 11 x 6 | 6x5 | 7x6 | 6x3 | 8x6 | 4 1/2 x 24 | ||||||
Queen-post Roof. | 30 | 9x4 | 5 1/2 x 4 | 4 1/2 x 4 | 4x3 | 7x4 | 8x4 | 4x4 | 4x2 | |||
32 | 10 x 4 | 6 x 4 | 5x4 | 4 x 3 1/2 | 7 1/2 x 4 | 8x4 | 4 1/2 x 4 | 4x2 | ||||
31 | 10 x 5 | 6 1/2 x 4 | 6x4 | 4 1/2x 3 1/2 | 8x4 | 8 1/2 x 5 | 5 x 4 | 44 x 2 | ||||
33 | 10 x 6 | 6 1/2 x 5 | 7x4 | 5 x31/2 | 8 x 4 1/2 | 8 1/2 x 5 | 5x4 | 4 1/2x2 | ||||
38 | 10 x 6 | 6x6 | 7x5 | 5x4 | 8x5 | 8 3/4 x 5 1/4 | 5 x 4 1/2 | 4 1/2 x 2 | ||||
40 | 11 x 0 | 7x6 | 7x6 | 6x4 | 8 1/2 x 5 | 8x6 | 5 x 4 1/2 | 4 1/2 x 2 | ||||
42 | 11 1/2 x 6 | 7x6 | 8x4 | 6x5 | 8x6 | 9x5 | 6x4 | 4 3/4 x 2 | ||||
45 | 12 1/2 x 6 | 7 1/4 x 6 | 8x6 | 6x6 | 8x6 | 9x6 | 6x4 | 5x2 |
 
Continue to: