On a tile roof, what size and spacing of rafters should be used?

On a tile roof, what size and spacing of rafters should be used?

• A. 2 x 4 spaced 12 in o.c
• B. 2 x 6 spaced 16 in o.c
• C. 2 x 8 spaced 24 in o.c
• D. 1 x 6 spaced 16 in o.c

Answer: (B)

Rafter sizing and spacing are chosen to safely carry the roof’s loads, including the heavy tile weight, without excessive deflection. For a tile roof, the dead load from the tiles is substantial, so using a sturdier rafter that won’t sag or fail is important. The combination of 2x6 lumber spaced 16 inches on center provides enough bending strength and stiffness to support typical tile loads over common spans, while not wasting material. It balances structural capacity with practicality for standard residential tile roofs. Smaller or more widely spaced rafters would risk sag or inadequate support for the tile. A 2x4 at 12 inches on center is generally undersized for tile, a 1x6 is also insufficient for rafters, and a 2x8 at 24 inches on center might be overbuilt for some spans but can be less favorable for tile due to reduced stiffness over wide spacing. In practice, always consult span tables for wood species and local loads, but 2x6 at 16 inches on center is a common, appropriate choice for tile roofs.

Rafter sizing and spacing are chosen to safely carry the roof’s loads, including the heavy tile weight, without excessive deflection. For a tile roof, the dead load from the tiles is substantial, so using a sturdier rafter that won’t sag or fail is important. The combination of 2x6 lumber spaced 16 inches on center provides enough bending strength and stiffness to support typical tile loads over common spans, while not wasting material. It balances structural capacity with practicality for standard residential tile roofs.

Smaller or more widely spaced rafters would risk sag or inadequate support for the tile. A 2x4 at 12 inches on center is generally undersized for tile, a 1x6 is also insufficient for rafters, and a 2x8 at 24 inches on center might be overbuilt for some spans but can be less favorable for tile due to reduced stiffness over wide spacing. In practice, always consult span tables for wood species and local loads, but 2x6 at 16 inches on center is a common, appropriate choice for tile roofs.