What is Type IV construction commonly referred to as?

Type IV construction is commonly referred to as "Ordinary construction." This classification includes buildings that are primarily built with non-combustible materials, like brick or masonry, but often includes some wood elements as well. The key characteristic of Type IV construction is that it has exterior walls made from non-combustible materials, while the floors and roof are constructed with heavy timber.

Heavy timber construction, while it utilizes lumber that is larger than standard framing members, is distinct from Type IV in terms of its materials. In what is considered heavy timber construction, the structural elements cannot be less than a prescribed minimum size, which provides greater fire resistance.

On the other hand, light frame and wood frame constructions refer to building techniques that utilize smaller, lighter lumber and are more susceptible to structural failure in the presence of fire compared to heavy timber or ordinary construction.

Understanding these distinctions is essential for fire fighters as they navigate different building types and their associated hazards during firefighting operations.