How far apart are rafters generally spaced on a gable roof?

How far apart are rafters generally spaced on a gable roof?

• A. 12 to 18 inches
• B. 24 to 36 inches
• C. 16 to 24 inches
• D. 6 to 12 inches

Answer: (C)

Rafters are spaced on center, which is the distance from the center of one rafter to the center of the next. For a typical residential gable roof, the common range is 16 to 24 inches apart. This spacing provides a good balance between enough support for the roof sheathing (often 1/2-inch plywood or OSB) and efficient use of lumber. If you tighten the spacing to around 12 inches, you’re using more material without a proportional gain in performance. If you space them much wider, like 24 to 36 inches, the sheathing and roof loads may deflect more unless other design measures are taken (such as thicker or stronger sheathing or additional framing). So 16 to 24 inches covers the standard, widely used range for typical gable roofs.

Rafters are spaced on center, which is the distance from the center of one rafter to the center of the next. For a typical residential gable roof, the common range is 16 to 24 inches apart. This spacing provides a good balance between enough support for the roof sheathing (often 1/2-inch plywood or OSB) and efficient use of lumber. If you tighten the spacing to around 12 inches, you’re using more material without a proportional gain in performance. If you space them much wider, like 24 to 36 inches, the sheathing and roof loads may deflect more unless other design measures are taken (such as thicker or stronger sheathing or additional framing). So 16 to 24 inches covers the standard, widely used range for typical gable roofs.