What is the maximum developed length above ground for a drain pipe before a cleanout is required?

• A. 75'
• B. 50'
• C. 100'
• D. 125'

Answer: (A)

Access for cleaning is built into drainage runs by placing cleanouts at intervals. For drain piping that runs above ground, you must not let the section between cleanouts exceed 75 feet of developed length. Developed length means the actual pipe length including any fittings that add length. This rule keeps blockages reachable with a snake or rodding tool. So if a run could be longer than 75 feet between access points, you need to add a cleanout somewhere in the middle so every section remains at or under 75 feet. The other distances aren’t the standard for above-ground drains; 75 feet is the limit that ensures practical cleaning access.