Minnesota Administrative Rules

4714.1103 SIZE OF LEADERS, CONDUCTORS, AND STORM DRAINS.

UPC sections 1103.1, 1103.2, and 1103.3 are amended to read as follows:

1103.1 Vertical Conductors and Leaders. Vertical conductors and leaders shall be sized by the maximum projected roof area and Table 1103.1. For sizes not listed under Table 1103.1, a minimum rainfall rate of 4 inches per hour must be used to size the rainwater piping.

1103.2 Size of Horizontal Storm Drains and Sewers. The size of building storm drains or building storm sewers or their horizontal branches shall be based on the maximum projected roof or paved area to be handled and Table 1103.2. For sizes not listed under Table 1103.2, a minimum rainfall rate of 4 inches per hour must be used to size the rainwater piping.

1103.3 Reduction in Size Prohibited. Except for siphonic roof drainage systems, storm drain piping shall not reduce in size in the direction of flow, including changes in direction from horizontal to vertical.

Statutory Authority:

MS s 326B.43

History:

45 SR 1007

Published Electronically:

September 27, 2021