Drainage

UPC Drainage Sizing Tables

UPC Appendix C Table C304.2 building drain sizing: DFU capacity by pipe size and slope.

Introduction

The UPC Appendix C provides drainage sizing tables. Table C304.2 sizes building drains and sewers based on DFU and slope. Table C304.3 sizes horizontal fixture branches and stacks.

UPC Appendix C Table C304.2 - Building Drains and Sewers

Pipe Dia (in)	1/16" slope	1/8" slope	1/4" slope	1/2" slope
2	-	-	21	26
2-1/2	-	-	24	31
3	-	20	42	50
4	-	180	216	250
5	-	390	480	575
6	-	700	840	1000
8	1400	1600	1920	2300
10	2500	2900	3500	4200
12	3900	4600	5600	6700
15	7000	8300	10000	12000

Notes

• Values are maximum DFU allowed for each pipe size at the given slope.
• 1/16" per foot slope is only permitted for pipes 8" and larger.
• Slope requirements: 1/4" per foot for pipes <3", 1/8" per foot for pipes >=3".

UPC Pipe Sizing Guide

How the Uniform Plumbing Code sizes water supply pipes using WSFU tables, and how Plumbing Booster applies UPC-specific values for both water supply and drainage.

Drainage Pipe Sizing Reference

Complete reference for drainage pipe sizing using IPC Table 710.1 and UPC Table 703.2, including slope requirements and maximum length limitations.

Sanitary Drainage Design Guide

Sanitary drainage system design involves sizing waste pipes using Drainage Fixture Units (DFU), selecting appropriate slopes, and ensuring venting adequacy.