Type IV building construction is also known as what?

Type IV building construction is commonly referred to as heavy timber construction. This type of construction uses large wooden beams and columns that are typically at least 8 inches in dimension. The heavy timber elements provide structural integrity while also possessing a level of fire resistance due to their mass. When exposed to fire, these large timbers burn more slowly than smaller timber, allowing for more time for occupants to evacuate and for firefighters to initiate rescue and firefighting operations.

Heavy timber construction incorporates a combination of combustible and noncombustible materials, but what distinguishes it is the use of heavy, solid wooden members that are integral to the structural system. The presence of these large wooden elements contributes to the building's unique characteristics, making it different from other construction types, like ordinary construction, which typically involves smaller wood members and lighter materials.

In contrast to the other construction types, which focus on different materials and design philosophies, heavy timber construction is well-recognized for its aesthetic appeal and structural capabilities while still presenting specific fire safety concerns that responders must address. Understanding the features of Type IV construction is crucial for incident safety officers when evaluating potential hazards at the scene of an incident.