At what intervals must horizontal copper pipe 1 inch and smaller be supported?

When considering the support requirements for horizontal copper piping that is 1 inch in diameter or smaller, the correct answer is that such pipes must be supported at intervals of 8 feet. This support interval is established to ensure the stability of the piping, preventing sagging or bending due to weight, which can ultimately lead to joint stress or failure.

Copper pipes, while they are relatively lightweight compared to some other materials, still require proper support to handle the pressures and stresses they may encounter in a plumbing system. By adhering to the 8-foot support requirement, plumbers can ensure that the pipe remains level and securely in place, safeguarding the integrity of the entire system.

In municipal or building code requirements, these specifications are typically laid out to protect the integrity of the plumbing work and to comply with safety and performance standards. Therefore, proper support is not only a matter of functional installation but also of compliance with relevant plumbing codes.