In Type IV construction, cross-laminated timber floors must be a minimum of how many inches in thickness?

• A. 2
• B. 3
• C. 4
• D. 6

Answer: (C)

In Type IV construction, which is also known as heavy timber construction, there are specific requirements for the thickness of materials used, especially when it comes to cross-laminated timber (CLT) floors. The minimum thickness requirement of 4 inches is established to ensure structural integrity, fire resistance, and overall performance of the building.

A thickness of 4 inches provides a robust platform that allows the material to perform effectively under various loads while also contributing to its fire-resistance properties. Thicker materials generally have better thermal mass, which enhances their ability to absorb and release heat. This thickness also helps to meet the fire safety regulations established in the building code, safeguarding the structure during an emergency.

In summary, the 4-inch requirement for cross-laminated timber floors in Type IV construction is vital for ensuring safety, structural stability, and compliance with fire resistance standards, making it the correct choice.