What is prohibited regarding underground piping beneath buildings?

The prohibition regarding underground piping beneath buildings relates specifically to the requirement for proper installation methods. When piping is installed underground, especially beneath structures, it is essential to protect it from potential damage and environmental factors. The installation of pipes without a conduit can lead to issues such as physical damage from shifting soil, movement from building foundations, or potential corrosion. A conduit provides a protective layer for the piping, ensuring its longevity and functionality.

Using plastic pipes, the allowance of copper pipes, or specific installation depths do not directly address the critical need for protection against external elements. The requirement for a conduit is specifically meant to safeguard the piping system, which is a vital aspect when considering the integrity and durability of underground installations in a building context.