Structural wood supports, such as columns, beams, and beams, must be at least 8 inches thick. Heavy roof and floor planks must be at least 6 inches thick. 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. Also known as heavy wood construction, Type IV construction has exterior walls made of non-combustible materials (masonry). The interior structural elements, including beams, columns, arches, floors and ceilings, are made of solid or laminated wood with no hidden spaces.
This wood must have dimensions large enough to be considered heavy wood. These dimensions vary depending on the specific code being used. 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. Imagine the sky-high skyscrapers of New York when you think about building Type I buildings. Or, closer to home, think of the large steel beams and tons of concrete that make up your local parking lot. This classification provides the highest level of safety because it uses materials such as cast concrete and steel beams, things that won't give in to fire very easily.
So if you want to build a single-family home, this type is probably not for you. With Type I, you'll get the highest level of fire protection, but it will be the most expensive and specific of all types of construction. 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.
If you think your project could fall into this category, it will have less fire protection than Type I, but you will have additional options for building materials and the code will be less rigid. 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. The main purpose of type III construction in the event of a fire is to contain the fire within the outer walls of the building and to prevent the fire from spreading to nearby buildings.
A method often used for type III buildings is construction with sloping or upward sloping slabs, in which the concrete is poured into the shape of a wall and then tilted upwards to form the walls of the building. This differs from precast concrete in that, when tilted, the concrete is poured in place and then lifted into position. The construction options for type III buildings are much more varied than those for types I and II, but once again, you'll have less fire protection. A good way to combat this is to use roof sprinklers and have high-quality ventilation systems that have a sequence of operations linked to the fire alarm system to control smoke and stop the spread of fire.
Columns, beams, and beams must be at least 8 inches thick to support building loads; heavy roof and floor boards must be at least 6 inches thick. Type IV buildings have non-combustible exterior walls and interior elements, but they do not have groups A and B. 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.
Despite the different types of construction, all structures burn out as a result of their content (mainly synthetic today) and, in the case of some of the current constructions, of their structural and aesthetic elements. In addition, knowing the types of construction saves lives by helping firefighters to anticipate dangerous situations, such as an electric shock, an air current and a landslide. Within Type V are smaller buildings, such as single-family residential houses, restaurants or small office buildings. V-type buildings can be particularly difficult for firefighters because exposed wood has no resistance to fire.
When it comes to construction, building size, purpose, coding, and budget come into play to help you determine the type you need. Also known as fire-resistant construction, Type I construction maintains its structural integrity during a fire. Understanding these types of construction gives any construction worker or firefighter a basic understanding of how these structures come together. Each type of construction is unique and firefighters must have a good working knowledge of building construction, the materials and connections used, how smoke and fire spread inside and outside structures, how fire affects materials and connections, what can fail, how it can fail, and what happens when flaw.
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 following comparative chart comes from Vincent Dunn's book, “Fire Extinguishing Strategy”, and shows the relationship between each type of construction and its potential for fire to spread and collapse. By contrast, Type 5 structures, the least resistant to fire, are lightweight and made of combustible materials that collapse soon after they catch fire. When firefighters encounter type 1 buildings, they must secure the stairs to ensure a safe evacuation.
Schools, businesses and houses with fireproof walls and wooden ceilings are distinguished as type 3 buildings. There are advantages and disadvantages to each type, the main concern is that the more fire resistant your building is, the higher the costs. . .
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