Non-Combustible Exposed metal floor and roof systems, as well as metal or masonry walls, are commonly employed. When subjected to fire, it is stable in terms of collapse. Type II construction is commonly encountered in new buildings and commercial structure remodels. Non-combustible materials are used to build the walls and roofing. These materials include ceramic tile, concrete, glass, and metal.
Type II construction is also known as fire-resistant construction. It provides adequate protection from fire for personnel and property. The key word here is "adequate." Fire codes require type II construction for any building over 10 feet high. The code requires fire-resistive barriers on all floors except the ground floor. The fire-resistive barrier should be a minimum of 1/8 inch thick solid sheet metal or mineral wool insulation. There should be an opening in the ceiling and wall for smoke to escape in an emergency. This is called fire-rated doors and windows. They must have a rating of 30 minutes or greater. The room itself cannot have a door that will block the way for people to escape in an emergency.
The purpose of this construction type is to prevent combustion or flaming conditions within the building. This prevents spread of fire from one room to another via heat radiation and air movement. Smoke and other products of combustion can't pass through non-combustible materials so there is no need for ventilation in type II buildings.
Except as authorized in Section 603 and elsewhere in this code, Types I and II construction are those in which the building elements mentioned in Table 601 are made of noncombustible materials. These include brick, stone, concrete, wood, metal, and other such materials. Type III construction is for buildings that are entirely composed of combustible material. This includes anything made of cloth, paper, or any other material that can burn.
The code requires certain minimum levels of safety to be maintained in buildings, including protection from fire. The only way to achieve this goal is by using one of the three types of construction described above. It is important to remember that even if a building is labeled as "fire-resistant," that does not mean it will resist fire for very long if it catches light inside.
Buildings must also be kept free of hazards that could cause injury or death if they fall on people or cause other damage. For this reason, all buildings should have permanent stairways and landings, and all doors and windows should be properly secured during inclement weather or when not in use.
Finally, buildings must be kept up according to some sort of maintenance program. This ensures that problems with heating systems, plumbing, or electrical wiring do not go unnoticed. Regular inspections may also reveal issues before a disaster occurs.
Type III construction consists of outer walls made of noncombustible materials and internal building elements made of any material approved by this code. The type of construction does not affect the fire rating of a wall system.
All outer wall surfaces in a Type III building must be completely dry. This includes ceilings, which require a water-resistant coating to prevent moisture from promoting the growth of mold or other fungi.
The code also requires that all wiring within the boundary of a Type III structure be enclosed in metal conduits. These conduits can either be part of the original construction or they can be installed after the fact. They must be continuous throughout, with no open ends. If an opening is needed for some reason, it must be fully covered with fire-resistive material.
The code allows for openings between rooms in a Type III building, as long as they are not less than 1/8 inch (3.2 mm) wide. These openings can be anything from a window to a door. They must be closed and sealed with fire-resistant material. Sealed means that there should be no space around the edge of the opening larger than 1/4 inch (6 mm).
Type II construction is the same as Type I construction, except that the building elements mentioned in Table 601 are noncombustible, unless otherwise specified in Section 603. What exactly is Type III construction? Type III construction means that any material used to construct a dwelling must be listed in Table 601 or be noncombustible. The only exceptions are that materials can be noncombustible for reasons other than being listed in Table 601 if they are approved by the local building official and include an indication of this fact on the drawing or specification for the work.
A Type II, Type III, or Type IV construction method is used depending on what type of material will be used to build the house. Type II houses use wood products such as plywood or lumber as their main building material. These products are considered combustible materials so they must be fire-resistant. Noncombustible materials can be used instead; for example, Type III houses use concrete or masonry as their main building material. These materials are not affected by fire so Type III houses can be built entirely out of these substances.
Type IV construction is used when a house uses steel or aluminum as its main building material. These products cannot burn but can become very hot during a fire so they should not be used in a house that may be burning at some distance from the actual structure.