Which construction type is described as having an excellent fire resistance yet capable of large conflagrations?

Which construction type is described as having an excellent fire resistance yet capable of large conflagrations?

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

Answer: (D)

Heavy timber construction uses large wood members that perform well in fire because the outer layer chars and protects the inner wood, slowing heat transfer and helping the structure maintain its strength for a longer period. That protective char gives excellent fire resistance ratings for the building. At the same time, the wood itself is fuel, and the substantial fuel load can allow the fire to grow and sustain once it gets going, potentially leading to a large conflagration if the fire isn’t contained. So this type combines strong fire resistance with a higher risk of a big, spreading fire due to the amount of wood present.

Heavy timber construction uses large wood members that perform well in fire because the outer layer chars and protects the inner wood, slowing heat transfer and helping the structure maintain its strength for a longer period. That protective char gives excellent fire resistance ratings for the building. At the same time, the wood itself is fuel, and the substantial fuel load can allow the fire to grow and sustain once it gets going, potentially leading to a large conflagration if the fire isn’t contained. So this type combines strong fire resistance with a higher risk of a big, spreading fire due to the amount of wood present.