Drain Types
Different drains need different slopes.
- Sanitary Minimum 1/4" per foot
- Storm Minimum 1/8" per foot
- Waste Minimum 1/4" per foot
- Vent Minimum 1/8" per foot
Flow Characteristics
Velocity
2-8 ft/sec ideal.
Capacity
Based on size.
Scouring
Self-cleaning.
Manning's
Flow formula.
Best Practices
- Support Every 4-6 feet.
- Cleanouts Required access.
- Venting Proper airflow.
- Testing Before covering.
Common Issues
- Bellies Low spots.
- Backfall Reverse slope.
- Clogs Poor flow.
- Sagging Poor support.