The underside of an arch, beam, or similar structure is called which term?

The underside of an arch, beam, or similar structure is called which term?

• A. Soffit
• B. Crown
• C. Keystone
• D. Tilt

Answer: (A)

The underside of an arch, beam, or similar structure is called a soffit. In architectural and plastering terminology, the soffit is the exposed surface on the bottom side of that member, which you often finish with plaster or drywall to create a smooth, continuous underside. It’s a distinct term from the crown, which is the top portion of an arch or curve; the keystone, located at the apex of an arch, is the central wedge that locks the curve in place. Tilt isn’t used to describe the underside in this context. So when you’re working under arches or beams, you’re thinking about finishing the soffit to ensure proper alignment and a clean, durable surface.

The underside of an arch, beam, or similar structure is called a soffit. In architectural and plastering terminology, the soffit is the exposed surface on the bottom side of that member, which you often finish with plaster or drywall to create a smooth, continuous underside. It’s a distinct term from the crown, which is the top portion of an arch or curve; the keystone, located at the apex of an arch, is the central wedge that locks the curve in place. Tilt isn’t used to describe the underside in this context. So when you’re working under arches or beams, you’re thinking about finishing the soffit to ensure proper alignment and a clean, durable surface.