What is the rating of flame spread?
The materials used in the construction of a building may burn if they are organic, containing carbon that can light in the air. Various wooden products, plastics and many fibers are flammable, which means they will burn if they are ignited by flame. The test used to determine the flammable burden of materials is the evaluation of the flame range. The wooden fiber board can be made with different adhesives that can speed up the flame burning rate. These factors need to be compared in a standard test and the flame span evaluation allows direct comparison of different materials.
The tunnel test is a common test assessment test. The material to be tested is connected to the top of the tunnel room, with holes only at each end. The windows located along the length of the tunnel room allow the flame span to observe. The sample is at least 18 inches (46 centimeters) wide and 25 feet (7.6 meters) long. The timer begins when the flame is applied to one end of the sample, and stops when the flame burn specificThe length of the sample.
The rate at which the flame moves through the sample depends on the amount of air flow. The movement of the air in the tunnel is carefully checked, so the evaluation of the flame span can be compared directly for various building materials. One end of the tunnel contains a shock absorber for incoming air and any smoke from the test is removed by the fan at the other end.
Standards are needed to compare the flame propagation values for different materials. Standards are materials that burn consistently in different tests, which gives a similar value for all tests. The zero flame span evaluation is obtained by attempting to light a plate made of asbestos fiber and cement that will not burn. The value of 100 is given by red oak wood, which gives a series of flammability for all other materials.
Building code authorities use information on flame to createStandards for new buildings. Materials with low rating in areas where fires are more common, such as residential garages or in areas of the world where fires are a seasonal problem, may be required for hospitals. Class I materials are usually considered to be the most resistant to fire and the V class are most flammable.
Material costs may not be the only factor in determining the cost of flame buildings. The concrete -based board may not be more expensive than the wooden board on board, although it has a very low fire ranking. The cost of construction may be more dependent on the structural weight of non -flammable materials. Cement or concrete materials can be quite heavy and can cost more because of the stronger structures needed to support them and increase their installation work.