For above-ground piping, what is the maximum developed length between cleanouts?

• A. 50 feet
• B. 60 feet
• C. 100 feet
• D. 75 feet

Answer: (D)

Cleanouts are access points that let you insert a drain snake or auger to clear blockages. The distance between these access points on a run is limited so a blockage can be reached and cleared without having to dismantle sections of piping. For above-ground drainage piping, the maximum developed length between cleanouts is 75 feet. This spacing keeps cleaning practical and efficient, since a longer run could place a blockage beyond the reach of standard cleaning tools, making maintenance harder and more costly. Shorter spacing would increase the number of cleanouts and installation cost, so 75 feet is the chosen standard.