For horizontal drains with a diameter of 4 inches or less, what is the maximum distance between cleanouts?

The maximum distance between cleanouts for horizontal drains with a diameter of 4 inches or less is established by plumbing codes to ensure accessibility for maintenance and cleaning. Having a maximum distance of 100 feet between cleanouts allows for effective access to the drainage system for any potential blockages or build-up that may occur over time.

This distance is critical for smaller diameter pipes, as they are more prone to clogs due to their reduced flow capacity. By maintaining cleanouts within this specific distance, plumbers can more easily and efficiently address issues, helping to maintain the functionality of the drainage system and preventing extensive and costly repairs.

While other distances are valid for different pipe sizes or configurations, the standard for 4-inch or smaller horizontal drains is specifically set at 100 feet to balance practical accessibility with effective plumbing system design.