- No galvanized steel or 304 stainless steel pipe shall be installed underground and shall be not less than 6 inches (152 mm) aboveground.
- ABS and PVC DWV piping installations shall be in accordance with Chapter 14 "Firestop Protection." Except for individual single-family dwelling units, materials exposed within ducts or plenums shall have a flame-spread index of not more than 25 and a smoke-developed index of not more than 50 where tested in accordance with ASTM E84 or UL 723. These tests shall comply with all requirements of the standards to include the sample size, both for width and length. Plastic pipe shall not be tested filled with water.
Exception: Where connected to a common building sewer, the drainage piping of two or more buildings located on the same lot and under one ownership shall be permitted to be vented by means of piping sized in accordance with Table 703.2, provided the aggregate cross-sectional area of vents is not less than that of the largest required common building sewer.
- For safe pans — not less than 4 pounds per square foot (lb/ft2) (19 kg/m2) or 1/16 of an inch (1.6 mm) thick.
- For flashings or vent terminals — not less than 3 lb/ft2 (15 kg/m2) or 0.0472 of an inch (1.2 mm) thick.
- Lead bends and lead traps shall be not less than 1/8 of an inch (3.2 mm) in wall thickness.
See Appendix B of this code for explanatory notes on the design of combination waste and vent systems.