722.5.2.2 Spray-applied fire-resistant materials.
BC § 722.5.2.2
The provisions in this section apply to structural steel beams and girders protected with spray-applied fire-resistant materials. Larger or smaller beam and girder shapes shall be permitted to be substituted for beams specified in approved unrestrained or restrained fire-resistant-rated assemblies, provided that the thickness of the fire-resistant material is adjusted in accordance with the following expression: h 2 = {[W 1 /D 1 ) + 0.60]/[(W 2 /D 2 ) + 0.60]} h 1 (Equation 7-17) where: h = Thickness of spray-applied fire-resistant material in inches. W = Weight of the structural steel beam or girder in pounds per linear foot. D = Heated perimeter of the structural steel beam or girder in inches. Subscript 1 refers to the beam and fire-resistant material thickness in the fire-resistance-rated assembly. Subscript 2 refers to the substitute beam or girder and the required thickness of fire-resistant material. Exception: The fire-resistance of structural steel beams and girders protected with intumescent or mastic fire-resistant coatings shall be determined on the basis of fire-resistance tests in accordance with Section 703.2.
