609.3 Under Concrete Slab.

Water piping installed within a building and in or under a concrete floor slab resting on the ground shall be installed in accordance with the following requirements: (1) Ferrous piping shall have a protective coating of an

approved type; machine applied and in accordance with recognized standards. Field wrapping shall provide equivalent protection and shall be restricted to those short sections and fittings necessarily stripped for threading. Zinc coating (galvanizing) shall not be deemed adequate protection for piping or fittings. Approved nonferrous piping shall not be required to be wrapped. (2) Copper or copper alloy tubing shall be installed without

joints where possible. Where joints are permitted, they shall be brazed, and fittings shall be wrought copper. For the purpose of this section, “within a building” shall mean within the fixed limits of the building foundation.