While many buildings look similar at first glance, the underlying materials affect their cost and durability, especially in the event of an emergency. Building codes classify all structures from type 1 to type 5, and this type of building reveals crucial information, such as fire resistance. The most fire-resistant buildings, type 1 structures, are built with concrete and protected steel, which can withstand high temperatures without collapsing. By contrast, Type 5 structures, the least resistant to fire, are lightweight and made of combustible materials that collapse soon after they catch fire.
Type 1 buildings are fire-resistant skyscrapers. Overall, these buildings measure more than 75 feet tall, including high-rise homes and commercial spaces. Because of their materials and design, type 1 buildings are considered to be the safest in the event of a fire, since they can withstand high temperatures for long periods of time. When firefighters encounter type 1 buildings, they must secure the stairs to ensure a safe evacuation.
In general, type 1 buildings are very durable and are unlikely to collapse if a fire breaks out. Many new or recently renovated commercial structures, including large stores and large shopping centers, are type 2 buildings. While these buildings generally have fire extinguishing systems, they are prone to collapsing when flames expose their metal roofs to high temperatures. Type 2 buildings include many non-combustible materials, but they still pose risks because they are more likely to collapse.
Schools, businesses and houses with fireproof walls and wooden ceilings are distinguished as type 3 buildings. While older buildings tend to have conventionally framed roofs, newer buildings offer lightweight roof systems. As firefighters approach type 3 buildings, they prioritize determining if the building is old or new in order to make appropriate ventilation decisions. Although type 3 buildings contain fire-resistant materials, their roof systems burn out quickly and their fire-cut beams pose a hazard to firefighters.
Many type 4 buildings were built before the 1960s with large pieces of wood. These buildings, easily recognizable by firefighters, have wooden walls and ceilings seen in barns, factories and old churches. They owe their robust structure to the wood connected by metal plates and bolts. While well-maintained type 4 buildings resist fire, the age of some of these buildings poses significant difficulties for firefighters.
“Ordinary” buildings have non-flammable load-bearing outer walls with combustible roofs, floors and interior walls.. Since each type of building construction is associated with unique building materials, they all have different levels of fire protection. The material of the fire-resistant group (type I) can generally last three to four hours against fire, while for wood and other structures of types IV and V, it depends on the thickness of the materials used. The basic speed is approximately 1 hour of fire resistance per 1.5 inches of wood thickness.
Like Type I buildings, the construction materials of Type II construction projects, including interior walls, frames, floors, roofs, and exterior walls, are all made of non-combustible materials, such as metal and concrete. Although their building materials are labeled as fireproof, they offer less fire protection than Type I because they are not usually coated with fire-resistant coatings, so a fire that spreads is likely to cause more damage. Buildings that fall into this category have exterior walls constructed of brick, masonry, concrete blocks, prefabricated panels, or other non-combustible materials. But the interior structures and the ceiling 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. Fire resistant structures measure a minimum of 75 feet in height. The walls, partitions, floors, ceilings and ceilings of these buildings can be fire resistant, meaning they have non-combustible surfaces.
This design prevents fire from spreading if an incident occurs. Construction crews use steel and concrete beams to build this type of structure, helping to 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 coatings.
One of the biggest differences between the two is that a fireproof building has no minimum height. In addition, the floors and roof are usually 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 ordinary building type of construction 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 accumulating. Construction crews construct interior walls and floors with fire-cut beams, which are special cuts of wood that are connected to an outer wall, but can break if damaged by fire. This helps to preserve the outer walls in the event of a fire and can prevent them from collapsing. Examples of ordinary building types include schools and residential houses.
Heavy-wood buildings have fireproof externals and some non-combustible interior structures. All wooden beams, columns and beams are at least 8 inches thick, while wooden boards for floors and ceilings are at least 6 inches thick. A heavy wood building is unlikely to collapse in a fire, but the fire may require large amounts of water to extinguish. Examples of heavy wood construction include barns, churches and mills.
Timber frame buildings have both wooden exterior and interior and can be highly combustible. This is the only type of building that uses all combustible externals. 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.
Ultimately, Type 1A stands out with the best fire resistance of the five types of building construction. Within Type V are smaller buildings, such as single-family residential houses, restaurants or small office buildings. If the roof is determined to be sustainable, a stair company should be able to effectively use chain saws to ventilate the building and make appropriate cuts depending on the type of roof system. Stair crews should frequent type 1 buildings in their area and be familiar with the systems they can find (elevators, HVAC, fire pumps, etc.).
In the end, building construction types will influence the purpose of the building, occupant load, square footage, height, proximity to other structures, windows, location of exits, fire resistance and the need for sprinklers. The floors and roofs of these buildings are also not combustible, since the floors are usually covered with lightweight concrete and the roofs are foam-insulated with metal construction. That's why building codes require type 1 fire-resistant structures to have complex fire resistance systems, such as self-pressurized ladders and HVAC systems to encourage air movement. If they approach a building with no signs of unreinforced masonry, firefighters should make noise on the walls to determine the type of wall before climbing onto the roof.
The many nuances of a building's use and size requirements can complicate things and create confusion about which type of construction is the most suitable. Each type of building has specific features that stair companies must be familiar with in order to ventilate the building as safely and efficiently as possible. The best way to identify a building is during pre-planning, but there are different characteristics that will help firefighters identify the type of building as they arrive on the scene. Understanding how fire spreads in different buildings allows firefighters to make crucial decisions about ventilation and water.