For unprotected I‑sections, the standard provides the correction factor ksh according to Equation 4.26a in Section 4.2.5.1 (2) to consider the shadowing effect. The term [Am/V]b is used there. This section factor includes Am, which represents the box enclosing the cross‑section (Index b = boxed). In the case of a three-sided fire exposure (a girder with a massive ceiling), the flange surface not exposed to fire is not taken into account when determining [Am/V]b.