A rafter is which of the following?

• A. Vertical column supporting the roof.
• B. A curved brace used in arches.
• C. An inclined beam that supports a roof and runs parallel to the slope.
• D. A horizontal tie beam in a wall.

Answer: (C)

Rafters are the inclined framing members that form the roof’s skeleton, running from the ridge down to the exterior walls. They support the roof deck and any finish, carrying the roof’s weight and transferring it to the walls. Because they follow the slope of the roof, they are parallel to that slope rather than vertical or horizontal. This makes them distinct from a vertical column (a post) that carries loads straight down, a curved brace used in arches, or a horizontal tie beam that connects opposite walls at the top of a wall line. In typical roof framing, rafters are spaced regularly and cut to sit on the ridge or ridge beam at the top and rest on the wall plates at the bottom, forming the slope and providing the roof with its overall shape and strength.