714.3 Selections of drainage pipe sizes.

Pipe shall be sized to prevent full-bore flow.

714.3.1 Selecting pipe wall roughness.

Pipe size calculations shall be conducted with the pipe wall roughness factor (k s ), in accordance with the manufacturer's specifications and as modified for aging roughness factors with deposits and corrosion.

714.3.2 Slope of horizontal drainage piping.

Horizontal drainage piping shall be designed and installed at slopes in accordance with Table 704.1.

Section PC 715: Backwater Valves

715.1 Sewage backflow.

Where fixtures, floor drains, or area drains are subject to overflow as the result of backwater from the public sewer system, accessible backwater valves shall be installed in the fixture drain pipe from such fixture, in the branch drain to such area drain or group of fixtures, or in the building drain at its point of exit from the building and downstream from the building trap. Buildings located in flood hazard areas shall be deemed to be subject to overflow as the result of backwater from the public sewer system and shall be provided with backwater valves in accordance with the additional requirements of Section 7.3.3 of ASCE 24 as modified by Appendix G of the New York City Building Code.