This type of building has an excellent record of fire resistance, but they're capable of large conflagration type fires

This type of building has an excellent record of fire resistance, but they're capable of large conflagration type fires

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

Answer: (D)

Heavy timber construction uses large solid timber members that resist fire through a protective char layer that forms on the surface. That char slows heat transfer and helps the structure maintain strength longer, so these buildings have an excellent fire-resistance record in terms of keeping the structure intact during a fire. At the same time, the substantial wooden fuel inside and the open, expansive interior can allow a fire to grow into a large conflagration if it becomes uncontained or if exposure from outside is intense. So the combination described—strong fire resistance of the structure plus potential for large, spreading fires due to the timber fuel—is characteristic of heavy timber construction.

Heavy timber construction uses large solid timber members that resist fire through a protective char layer that forms on the surface. That char slows heat transfer and helps the structure maintain strength longer, so these buildings have an excellent fire-resistance record in terms of keeping the structure intact during a fire. At the same time, the substantial wooden fuel inside and the open, expansive interior can allow a fire to grow into a large conflagration if it becomes uncontained or if exposure from outside is intense. So the combination described—strong fire resistance of the structure plus potential for large, spreading fires due to the timber fuel—is characteristic of heavy timber construction.