Section 890.1570  Vent Headers

Connection of Vents.  Stack vents and vent stacks may be connected into a common vent header at the top of the stacks and then be extended through the roof to the outside atmosphere at one point.  This header shall be sized as provided in Appendix A, Table K, the number of units being the sum of all units on all stacks connected thereto, and the developed length being the longest vent length from the interception at the base of the most distant stack to the vent terminal to the outside atmosphere, as a direct extension of one (1) stack.