Conventional Flat Roof Characteristics

Conventional Flat Roof Characteristics

• A. Rafters are metal and there are no internal supports.
• B. Rafters wood 2x3 with plywood only.
• C. Wood rafters 2x6 or larger spanning outside walls with possible internal supports; rafters may be suspended by metal hangers; older roofs may have scissor bracing; 1x6 sheathing or plywood or both.
• D. There is always continuous internal steel supports.

Answer: (C)

Conventional flat roof construction uses wood framing with properly sized rafters and appropriate bracing. Typically, rafters are wood and sized at 2x6 or larger, spanning between exterior walls with the potential for internal supports to carry loads. Rafters may be suspended by metal hangers to secure them, and older roofs may show scissor bracing for lateral stability. The roof deck or sheathing is usually 1x6 boards or plywood, or a combination of both. This combination reflects common practice for a conventional flat roof, whereas metal rafters with no internal supports, undersized 2x3 rafters, or a requirement for continuous internal steel supports do not fit the standard construction.

Conventional flat roof construction uses wood framing with properly sized rafters and appropriate bracing. Typically, rafters are wood and sized at 2x6 or larger, spanning between exterior walls with the potential for internal supports to carry loads. Rafters may be suspended by metal hangers to secure them, and older roofs may show scissor bracing for lateral stability. The roof deck or sheathing is usually 1x6 boards or plywood, or a combination of both. This combination reflects common practice for a conventional flat roof, whereas metal rafters with no internal supports, undersized 2x3 rafters, or a requirement for continuous internal steel supports do not fit the standard construction.