Which of the following materials is commonly used for fire-resistant doors in Japanese buildings

Which of the following materials is commonly used for fire-resistant doors in Japanese buildings

Which of the following materials is commonly used for fire-resistant doors in Japanese buildings, required to meet the 1-hour fire resistance rating?

A. Solid wood

B. Aluminum alloy

C. Steel sheet with rock wool core

D. Glass fiber reinforced plastic (GFRP)

E. PVC plastic

Answer: C

Explanation: Fire-resistant doors in Japan are typically made of steel sheets with a rock wool core. Rock wool provides excellent fire insulation, and the steel sheet ensures structural integrity, allowing the door to meet the required 1-hour fire resistance rating—this is a common material and fire safety