Plumbing Drain Systems
IRC Sections
General
P2601.2 | Home must be connected to sanitary drainage system | |
P2603.2.1 | Protection against damage | |
P2603.3.1 | Penetrations | |
P2603.4 | Pipes through foundation walls | |
P2603.5 | Freezing |
General Installation Requirements
P2604.1 | Trenching and bedding | |
P2604.2 | Water service and sewer in same trench | |
P2604.3 | Backfilling | |
P2604.4 | Protection of footings | |
P2605.1 | Supports | |
P2606.1 | Sealing of annular spaces | |
P2607 | Waterproofing of openings | |
P3008 | Sewage backflow and backwater valve requirements |
Spacing Chart for Different Materials (spacing in feet)
Material Max Horizontal ft Max Vertical ft
PVC | 4 | 10 |
CPVC 1 inch or smaller | 3 | 10 |
PEX 1 inch or smaller | 2.67 | 4 |
PEX 1 ¼ inch or larger | 4 | 10 |
COPPER (1 ¼ inch or smaller) | 6 | 10 |
COPPER (1 ½ inch or larger) | 10 | 10 |
Drain pipe requirements
P3003.9.2 | Purple primer not required on glued pipe (not pressurized) | |
P3003.13 | Joints between different materials | |
P3005.1 | Drainage fittings and connections | Table |
P3003.2 | Prohibited joint connections (no glued abs to pvc) | |
P3005.2 thru P3005.6 | Clean out requirements (notes where required, direction changes and sizes | |
P3005.3 | Required horizontal slope | |
P3005.4.2 | Building drain and sewer size and slope | table |
P3005.4 | Drain pipe sizing | |
P3006 | Sizing of drain pipe off sets |
Drainpipes for individual fixtures or sinks
P2706 | Strainer/basket required for drain receptors | |
P2706.1.2 | Standpipes (min 18” max 42”) | |
P2706.1.2.1 | Washing machine standpipe (minimum 30 “) | |
P2706.2 | Prohibited waste receptors | |
P2707.1 | Directional fitting or tailpipe required for disposal or dishwasher | |