R609.8

Section R609.8 is titled 'Mullions' and covers requirements for vertical window frame members. A cross-reference to a standard which mullions must conform to, an alternative allowance for mullions to be designed by accepted engineering practice in lieu of the standard, cross-reference to subsections which mullions tested as stand-alone units or by accepted engineering practice must conform to, and cross-reference to subsections which mullions must conform to when tested as an assembly is established. The purpose of this section is to prevent mullion structural failure.

The model shows a wall section with two windows separated by a highlighted mullion.