Determine the purchase quantity of 2 × 8 rafters needed for the roof in Figure 14.68. The slope of the roof is 4:12. From Figure 14-48, the slope length factor is 1.055.

What will be an ideal response?


Run = 28?8? / 2 = 14?4?

Length = 14?4? × 1.055 = 15.12? – Use 16? rafters

Number of spaces = 38?8? × 0.75 spaces per foot = 29 spaces

Use 30 for each half of the roof for a total of 60.

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