In building construction and fire prevention there are organizations that have created a useful system on how to determine which type of building falls into which category. The ICC (International Code Council) and NFPA (National Fire Protection Association) create these building codes for firefighter safety. The two most commonly known standards for building classification are NFPA 5000 and also the International Building Code (IBC). The two are very similar, however they differ in subcategorization. The International Building Code uses Roman numerals to indicate the type of construction. As well as subcategories with letters for every five classes and the amount of fire resistance expected for each building. NFPA uses Roman numerals behind the construction type. Unlike the IBC, the NFPA uses a 3-digit number system to subcategorize the hourly fire rating for load-bearing walls, beams and columns, and floor construction. The IBC and NFPA divide construction into five classes, Type I, Type II, Type III, Type IV, and Type V. Type V buildings are known as wood-frame buildings. To reduce Type V buildings to the essentials, they are built with lightweight materials to save the contractor money. This type of construction is the most dangerous for firefighters due to the lightweight and cheap materials used. Some of the wood frame buildings are log cabin, post and frame, balloon frame, deck frame, board and beam and truss frame. Log cabins are structures built from tree trunks. The ends are notched in order... in the center of the paper... in most cases, if steel were to be used in a Type I structure, it would be to reinforce concrete because concrete has a strong compressive strength but weak in tensile strength. If there is any exposed steel, it is flame retardant with a flame retardant. Mainly the fire risks that firefighters face in these structures are usually due to human errors during the construction of the buildings or when occupants occupy the building. On construction sites, welding, cutting, plumber's torches, electrical cables and heaters all pose a fire hazard. The other risk of this type of building would be the collapse of the concrete walls or floors during construction.