For piping larger than two inches in diameter, how many inches of horizontal service space shall be provided in front of the cleanout?

For piping larger than two inches in diameter, the requirement for horizontal service space in front of the cleanout is established by plumbing codes to ensure accessibility for maintenance and cleaning. Having 18 inches of horizontal space is necessary to allow a technician to perform inspections or repairs adequately without obstruction. This clearance also facilitates the use of standard tools and equipment that may be needed during service.

The 18-inch figure is derived from industry standards that prioritize safety and convenience during maintenance activities, ensuring that enough room is available to work effectively without compromising safety or accessibility. Adhering to this requirement is essential for proper plumbing design and to meet local building codes that govern the installation and maintenance of plumbing systems.