Which term describes a lightweight truss design noted by the bow shape of the top chord?

• A. Cast-in-place Concrete
• B. Eave
• C. Bowstring Truss
• D. Cockloft

Answer: (C)

A bowstring truss is a lightweight roof truss characterized by a top chord that is curved into a bow shape, forming a bowstring-like profile when paired with a straight bottom chord and verticals. This bow-shaped top chord is the defining feature, allowing the truss to span wide spaces with relatively few members while keeping weight down. In practice, recognizing this type helps you anticipate how it behaves under fire—slender members can fail quickly, and the curved top chord can lead to rapid loss of roof support. The other terms refer to different things: cast-in-place concrete is poured on site, an eave is the roof’s edge overhang, and a cockloft is the space between the ceiling and the roof—not a truss.