Joists are best described as which of the following in structural framing?

• A. a decorative element
• B. also beams (steel or wood) which provide direct support for a floor or roof system
• C. vertical supports for arches
• D. curved features used in vaults

Answer: (B)

Joists are horizontal framing members that carry the load of a floor or ceiling by spanning between supports and transferring that load to beams or bearing walls. They are designed to resist bending and provide a stable platform for subflooring and finish flooring, usually made of wood or steel and spaced at regular intervals (like 16 inches on center). This is why they’re described as providing direct support for a floor or roof system.

The other options don’t fit because a decorative element isn’t a structural member, vertical supports for arches are columns or piers, and curved features used in vaults refer to arches or vault rib structures rather than floor framing.