Since each type of building construction is associated with unique building materials, they all have different levels of fire protection. The fire-resistant group (Type I) material can generally last three to four hours against fire, whereas for wood and other Type IV and Type V structures, it depends on the thickness of the materials used. The base rate is approximately 1 hour of fire resistance per 1.5 inches of wood thickness. As with Type I buildings, construction materials for Type II construction projects, including interior walls, frames, floors, roofs and exteriors, are made of non-combustible materials such as metal and concrete.
Although their construction materials are labeled as non-combustible, they offer less fire protection than Type I because they are not usually coated with fire-resistant coatings, so the spread of fire would likely cause more damage. Buildings that fall into this category have exterior walls constructed of bricks, masonry, concrete blocks, prefabricated panels, or other non-combustible materials. But the interior structures and the roof can have wooden frames. If you want a timber-framed structure with a higher level of fire protection, Type IV buildings are a good choice.
However, remember that construction costs will be more expensive than the last type of construction, Type V. Although many buildings look similar at first glance, the underlying materials greatly affect cost and durability, especially in an extreme situation, such as a fire. All buildings are rated Type 1 to Type 5, and this type of building provides crucial information about a building's fire resistance. 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.
In contrast, Type 5 structures, the least fire-resistant, are lightweight structures made of combustible materials that can collapse soon after catching fire. When firefighters encounter Type 1 buildings, their primary purpose is to secure the stairs to ensure safe evacuation. In general, type 1 buildings are extremely durable and are unlikely to collapse if a fire breaks out. Many new or recently renovated retail structures, including “department stores” and large shopping malls, are Type 2 buildings.
While these buildings generally have firefighting systems, they are prone to collapse due to their metal roofs, which fail at high temperatures, even if not directly affected by flames. In general, type 2 buildings include many non-combustible materials, but they are nevertheless risky due to their increased risk of collapse. Both new and old buildings, such as schools, businesses and homes, can use the “ordinary construction” that distinguishes Type 3 buildings, which consist of non-combustible walls with wooden roofs. Although all Type 3 buildings have wooden roofs, older buildings tend to have conventional framed roofs, while newer buildings often have lightweight roof systems.
As firefighters approach Type 3 buildings, their priority is to determine if the building is old or new in order to make the right ventilation decisions. In general, type 3 buildings often contain fire-resistant materials, but lightweight roof systems can burn out quickly and beams cut by fire can cause hazardous situations for firefighters. Many buildings were built before the 1960s using large pieces of wood, and are known as Type 4 buildings. Easily recognized by firefighters, these buildings have wood in the walls and roof openings, barns, factories and old churches often use this type of construction.
In all buildings, wood is connected by metal plates and bolts, forming a robust structure. In general, Type 4 buildings withstand fire quite well if they are in good condition, but the age of many of these buildings presents significant difficulties for firefighters. Fire resistant structures have a minimum height of 75 feet. The walls, partitions, floors, ceilings and roofs of these buildings can be fire resistant, which means they have non-combustible surfaces.
This design prevents a fire from spreading if an incident occurs. Construction crews use steel and concrete beams to build this type of structure, which helps prevent collapse. Examples of fire-resistant buildings include high-rise structures, such as office buildings or hotels. Unlike fire-resistant buildings, non-combustible buildings have fire-extinguishing systems instead of fire-resistant cladding.
One of the biggest differences between the two is that a non-combustible building has no minimum height. In addition, floors and roof are often made of metal, which helps prevent the possible spread of fire. Examples of non-combustible structures include shopping malls and new school buildings. Contractors and builders often use the type of construction of ordinary buildings for residential housing, including brick or block walls with wooden floors and ceilings.
While common building construction types may not be fire resistant, they have good ventilation to help prevent potentially combustible gases from building up. Construction crews build interior walls and floors with fire-cut joists, which are special cuts of wood that connect to an exterior wall, but can detach when damaged by fire. This helps preserve exterior walls in the event of a fire and can prevent them from collapsing. Examples of common building types include schools and residential homes.
Heavy timber buildings have non-combustible exteriors and some non-combustible interior structures. All wooden beams, columns and beams are at least 8 inches thick, while wood planks for floors and ceilings are at least 6 inches thick. A heavy wooden building is unlikely to collapse in a fire, but the fire may require large amounts of water to extinguish. Examples of heavy timber construction include barns, churches, and mills.
Timber-framed buildings have both wooden exteriors and interiors and can be highly combustible. This is the only type of building that uses all exterior fuels. Timber frame buildings may have a lower construction cost than other types. You can find this type of building construction in modern houses and garages.
It's best to identify a building during pre-planning, but there are different characteristics that will help firefighters identify the type of building as they stop at the scene. Ventilation in such buildings is not an option, because the roof must also be composed of non-combustible materials. Knowing the different types of building construction is useful for professionals who design, build or maintain structures. If you don't have an eye for those details yet, it's important to know the five types of building construction.
This type is called “non-combustible”, not because of its fire resistance, but because of the fuel provided by the building. By distinguishing these building constructions into five types, you can personally decide which structure is best for a new construction. Type V includes smaller buildings, such as single-family residential houses, restaurants, or small office buildings. Each building type has specific characteristics that stair companies must be familiar with in order to ventilate the building as safely and efficiently as possible.
If you think your project might fall into this category, you'll have less fire protection than Type I, but you have additional options for building materials and the code will be less rigid. Type V buildings can be particularly difficult for firefighters because exposed wood has no fire resistance. The most common types of roof systems in a commercial Type 3 construction environment include parallel cable armor systems and panel roofs. .