In Type I construction, if height and area exceed limits, what must be used for walls and floors?

• A. Combustible wood framing
• B. Water-resistant coatings
• C. Plastic sheathing
• D. Fire-resistive construction for walls and floors

Answer: (D)

In Type I construction, the structure is designed to be highly fire resistant, using noncombustible or heavily protected materials. When the height or area of a Type I building would exceed the code limits, the protection level must be maintained by using fire-resistive construction for the walls and floors. This means the walls and floor/ceiling assemblies are rated to resist fire for a specified period, helping to keep the structural elements stable longer during a fire.

Fire-resistive construction can involve reinforced concrete, protected steel framing, or masonry with rated fire-resistant assemblies. The goal is to preserve structural integrity and prevent early collapse by keeping the fire from compromising load-bearing elements.

The other options don’t provide that required level of structural fire resistance. Combustible wood framing would not meet Type I’s fire-resistance expectations; water-resistant coatings and plastic sheathing don’t offer the necessary fire-resistance ratings for walls and floors in this context.