Fire-Retardant Treated Lumber Use: Type III-A Buildings

Type III-A building needs to stay within the limitations of allowable height, allowable number of stories and allowable area requirements of the International Building Code. Type III-A buildings are required to have exterior walls of noncombustible materials to meet a 2 hour fire-resistance rating which permits FRTW to be used. The noncombustible material must meet the criteria called out in  ASTM E 136 and FRTW must comply with the International Building Code. Different types of materials will require different specifications for connectors and fasteners. Some buildings may consist of two different construction types but the building will be classified as the lowest of the two types present.