It is the only construction category that allows combustible exterior walls, as well as combustible structural elements inside. Frames, walls, floors and ceilings are made wholly or partially of wood. Walls and frames can be constructed of any material allowed by code with type V construction, usually wood. A type V-B construction, the most basic, does not require a fire rating for any of the building elements.
The construction elements are the main structural frame, the bearing walls, the non-bearing walls, the floor construction and the roof construction. It is an economical option but, because the structure has inherently lower fire ratings, it has limitations on use and may need greater setbacks or barriers to protect adjacent properties. In general, type 3 buildings often contain fire-resistant materials, but lightweight roof systems can burn out quickly and fire-cut beams can cause hazardous situations for firefighters. A keen sense of construction types saves lives by helping firefighters anticipate hazardous situations such as electric shocks, drafts and landslides.
But Type V construction buildings are always smaller than a building of the same use built for a stricter type of construction. The exterior walls of Type III construction are constructed of bricks, masonry, concrete blocks, prefabricated panels, or other non-combustible materials. The type of activities carried out within a structure can help determine if Type V timber frame construction is an option. Any structure that requires a permit to build, modify, or remodel should be classified by construction type and occupancy.
If the roof is determined to be sustainable, a ladder company should be able to effectively use chainsaws to ventilate the building and make appropriate cuts based on the type of roof system. Type V construction requires that all major building elements except unsupported interior walls and partitions be of one-hour fire resistant constructions. Many buildings were built before the 1960s using large pieces of wood, and are known as Type 4 buildings. The most fire-resistant buildings, Type 1 structures, are constructed of concrete and protected steel, materials that are capable of withstanding high temperatures for a long time.
Although all Type 3 buildings have wooden roofs, older buildings tend to have conventional framed roofs, while newer buildings tend to have lightweight roof systems. Construction without Type V protection has no fire resistance requirements, except where the code requires protection of exterior walls due to their proximity to a property line. As for the typical ventilation operation of climbing to the roof and making a hole, that's not really an option when it comes to a type 1 construction. Understanding the types of construction is absolutely vital for firefighters and anyone in the construction industry, but everyone can enjoy the structures that surround them a lot by learning more about the five types of buildings.