18-29-711.3 Horizontal stack offsets.
   A stack with a horizontal offset located more than four branch intervals below the top of the stack shall be vented in accordance with Section 914 and sized as follows:
   1.   The portion of the stack above the offset shall be sized as for a vertical stack based on the total number of drainage fixture units above the offset.
   2.   The offset shall be sized in accordance with Section 18-29-710.1.1.
   3.   The portion of the stack below the offset shall be sized as for the offset or based on the total number of drainage fixture units on the entire stack, whichever is larger (see Table 18-29-710B, Column 4).