Which construction type is associated with curved or vaulted ceilings that use glue-laminated beams which may fail in a fire?

Which construction type is associated with curved or vaulted ceilings that use glue-laminated beams which may fail in a fire?

• A. Type I
• B. Type II
• C. Type III
• D. Type IV

Answer: (D)

Heavy timber construction, known as Type IV, is defined by large wooden structural members, including glue-laminated beams, used to create long spans and often curved or vaulted ceilings. In a fire, these substantial wood members can maintain some load-bearing capacity while they char on the outside; however, as the fire progresses, the cross-section of the wood reduces, and the glue-laminated or built-up members can lose strength or fail, leading to structural compromise. This combination of curved or vaulted ceilings with glue-laminated timber is characteristic of Type IV, setting it apart from other types that rely on noncombustible or fire-resistive materials.