NASCLA Accredited Commercial General ContractorWoodMedium
A commercial building project specifies the use of Heavy Timber construction for its exposed structural elements. According to the International Building Code (IBC), which of the following is the minimum nominal dimension for a column in Heavy Timber (Type IV) construction?
- A12 inches by 12 inches
- B6 inches by 6 inches
- C10 inches by 10 inches
- D8 inches by 8 inches
Show answer & explanationAnswer & explanation
Correct answer: D. 8 inches by 8 inches
The IBC specifies minimum nominal dimensions for structural members in Heavy Timber (Type IV) construction to ensure adequate fire resistance through charring. For columns, the minimum nominal dimension is 8 inches by 8 inches.
Why the other options are wrong
- A. 12x12 is also acceptable but exceeds the minimum requirement.
- B. 6x6 is typically not sufficient for IBC Heavy Timber columns.
- C. While 10x10 would be acceptable, it is not the minimum.
IBC Heavy Timber Columns
Minimum nominal dimensions for wood columns in Type IV (Heavy Timber) construction as defined by the International Building Code, primarily for fire resistance.
- Type IV construction relies on the mass of timber for inherent fire resistance.
- Minimum dimensions prevent rapid structural failure during a fire.
- IBC specifies different minimums for columns, beams, and arches.
Memory trick: Heavy columns stand tall, 8x8 for all.