What is the maximum allowable spacing for vent pipes in plumbing?

The maximum allowable spacing for vent pipes in plumbing is indeed 1.5 meters (5 feet). This standard is established to ensure that vent pipes effectively allow for the proper release of gases and the maintenance of atmospheric pressure within the drainage system. Adequately spaced vent pipes can help prevent negative pressure in the drainage system during discharge, which can lead to siphoning of traps and subsequent sewer gas infiltration into living spaces.

Maintaining appropriate spacing, as specified, enhances the overall efficiency of the plumbing system and contributes to health and safety by minimizing any potential risks associated with improper ventilation.