722.4.1.1 Equivalent thickness.
BC § 722.4.1.1
The fire-resistance ratings of walls or partitions constructed of solid or hollow clay masonry units shall be determined from Table 722.4.1(1) or 722.4.1(2). The equivalent thickness of the clay masonry unit shall be determined by Equation 7-8 where using Table 722.4.1(1). The fire-resistance rating determined from Table 722.4.1(1) shall be permitted to be used in the calculated fire-resistance rating procedure in Section 722.4.2. T e = V n / LH (Equation 7-8) where: T e = The equivalent thickness of the clay masonry unit (inches). V n = The net volume of the clay masonry unit (inch 3 ). L = The specified length of the clay masonry unit (inches). H = The specified height of the clay masonry unit (inches).













