Question

In Type 4 construction, structural members are generally expected to be greater than 8 inches in diameter and made of solid wood. The fire-rating for all structural members that are made of wood is generally 2 hours. In type 4 constructions, what fire-rating must all non-wood material possess?

Answer 1

In Type 4 construction, non-wood materials are generally required to have a fire-resistance rating comparable to that of wood, typically around 2 hours, although the exact rating can vary based on material and use.

Step-by-step explanation:

In Type 4 construction, which is commonly known as Heavy Timber or Mill construction, the primary structural frame components are made of solid wood which is expected to have at least a 2-hour fire rating. For non-wood materials used within Type 4 constructions, the fire-rating requirement varies by the material and its use within the building. However, these materials typically are required to have a fire-resistance rating comparable to the wood used, which would also generally be around 2 hours. It is important to note that local building codes and the International Building Code (IBC) provide specific fire-rating requirements and these should be consulted for precise regulations.

For instance, masonry used in fireproofing for Type 4 construction may need to match the 2-hour fire-rating of the structural members. The idea, just like with wood, is that the structural integrity of the building is maintained for the duration of the fire-resistance period, allowing for safe evacuation and firefighting operations.