Fire Proofing Steel

685 Words3 Pages
Steel is any range of alloys of iron and carbon that contain less than two percent carbon. Typical structural steel is iron whose properties have been optimized for structural purposes by controlling the amounts of carbon and other elements in the metal, usually less than three-tenths of one percent carbon. Although steel will not burn, steel expands and softens when heated which typically leads to steel losing its structural integrity. This means that steel must be properly fireproofed in order to prevent structural failure. Structure fires are not hot enough to melt the steel, but the fire is able to weaken the steel significantly. Originally, steel was fire proofed by encasing the steel in brick masonry or poured concrete. This method was effective but added a substantial amount of weight to the load that the steel had to tolerate. Adding this extra weight to the frame increased the costs of construction. Spray-on fireproofing for structural steel was developed as a lightweight, low cost option where the fireproofing material does not need to serve as a finished surface. Typical structural steel systems that use spray-on fireproofing include columns, beams and open web joists in houses, buildings, factories and many other types of construction. Structural steel that is normally in plain view does not usually use spray-on fireproofing because it leaves an unattractive look. The materials sprayed-on the steel generally consist of a gypsum based plaster, a fiber and a binder, or a cementitious mixture. The mix must be controllable for installation, easy clean up, and have a strong adhesive in order to stay on the steel. The spray-on materials insulate the steel from high temperatures for long periods of time. Spray-on fireproofing can be done to specific thickness requirements as well as hours of protection. Materials The materials necessary to complete spray-on
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