Pipe Support Spacing Chart — IPC Table 308.5 Hanger Intervals
Maximum pipe hanger and support spacing by piping material per IPC Table 308.5, horizontal and vertical, for common plumbing piping.
Updated August 22, 2026
Pipe sags between supports, and every material sags differently — so the International Plumbing Code sets a maximum hanger interval per material in Table 308.5, reproduced below. The pattern is intuitive once you see it: rigid metals span far (steel and copper pipe every 12 ft), rigid plastics need help every few feet because they creep under sustained load (PVC and ABS every 4 ft, small CPVC every 3 ft), and flexible tubing barely supports itself at all — PEX every 32 inches horizontally, which in practice means a support at every other joist bay.
Vertical (riser) spacing is a separate column and follows different logic: gravity pulls along the pipe rather than across it, so most materials allow 10–15 ft vertically — typically a support at each floor — with the footnoted plastics also needing a mid-story guide at 2 inches and smaller to stop the riser from buckling sideways. Two cautions before you copy numbers onto a drawing: these are the IPC values, and jurisdictions on the Uniform Plumbing Code use a differently structured table that does not match row-for-row (see the FAQ); and code intervals are minimums for ordinary gravity and pressure piping — engineered systems (per MSS SP-58 practice) space supports for actual loads, valves, and equipment, which can demand closer spacing than the code floor.
IPC Table 308.5 — Hanger Spacing by Piping Material
| Piping material | Max horizontal spacing (ft) | Max vertical spacing (ft) | Notes |
|---|---|---|---|
| ABS pipe | 4 | 10 | b |
| Aluminum tubing | 10 | 15 | — |
| Brass pipe | 10 | 10 | — |
| Cast-iron pipe | 5 | 15 | a |
| Copper or copper-alloy pipe | 12 | 10 | — |
| Copper or copper-alloy tubing, 1-1/4″ and smaller | 6 | 10 | — |
| Copper or copper-alloy tubing, 1-1/2″ and larger | 10 | 10 | — |
| PEX pipe (cross-linked polyethylene) | 2.67 (32 in) | 10 | b |
| PEX-AL-PEX pipe | 2.67 (32 in) | 4 | — |
| CPVC pipe or tubing, 1″ and smaller | 3 | 10 | b |
| CPVC pipe or tubing, 1-1/4″ and larger | 4 | 10 | b |
| Steel pipe | 12 | 15 | — |
| Lead pipe | Continuous | 4 | — |
| PE-AL-PE pipe | 2.67 (32 in) | 4 | — |
| Polypropylene (PP) pipe or tubing, 1″ and smaller | 2.67 (32 in) | 10 | b |
| Polypropylene (PP) pipe or tubing, 1-1/4″ and larger | 4 | 10 | b |
| PVC pipe | 4 | 10 | b |
| Stainless steel drainage systems | 10 | 10 | b |
a — Cast-iron horizontal spacing may increase to 10 ft where 10-ft pipe lengths are installed. b — For sizes 2″ and smaller, install a mid-story guide between vertical supports. 1 ft = 304.8 mm. Support piping at each horizontal branch connection and near concentrated loads regardless of interval.
Sources & Further Reading
- International Plumbing Code, Table 308.5 — Hanger Spacing, digit-verified row-for-row across a municipal reproduction of the 2009 IPC table (McPherson, KS handout) and the state-adopted Alabama Plumbing Code 2015 (IPC) via the UpCodes public viewer; sampled rows additionally match ICC’s public 2024 IPC text (values unchanged across these editions)
Frequently Asked Questions
How often do I need to support PEX?
Horizontally, every 32 inches (2.67 ft) per IPC Table 308.5 — every other 16″ o.c. joist bay works out naturally. Vertically every 10 ft, with a mid-story guide for 2″ and smaller risers. PEX-AL-PEX composite tubing is different: its aluminum core lets it hold a bend, but the IPC still limits it to 32 inches horizontally and only 4 ft vertically.
Why does the UPC give different hanger spacing than this table?
Because the Uniform Plumbing Code writes its support table (UPC Table 313.1) around joint types as well as materials — cast iron with compression gaskets is supported at every other joint, copper splits at 2 inches rather than 1-1/2, and CPVC gets a different interval. The two codes genuinely disagree for several materials, so never mix rows: use this IPC table in IPC states and the UPC table where the UPC is adopted. Your local amendment can override either.
Why can copper pipe span 12 feet but copper tubing only 6?
The table distinguishes rigid pipe from tubing by wall and temper. Threaded-weight copper pipe is thick and stiff, so it spans like steel (12 ft). Drawn copper tube in small sizes (1-1/4″ and smaller) is far more flexible and creeps at hot-water temperatures, so it needs a hanger every 6 ft; at 1-1/2″ and larger the tube stiffens enough for 10 ft. Same metal, different section.
Do these intervals apply to horizontal drains that need slope?
Yes — and the slope is why sag matters so much on DWV plastics. A 4-ft hanger interval on PVC exists largely to preserve the 1/4-in-per-foot (or 1/8-in) grade: a bellied section traps water and solids. Hang drainage so the pipe cannot sag below its grade line between supports, add a hanger at every horizontal branch connection, and support cast iron at each hub or coupling per the footnote when using 5-ft lengths.
Try the Calculators
Pipe Support Spacing Chart — IPC Table 308.5 Hanger Intervals — reuven.tools/reference/pipe-hanger-spacing — verified against: International Plumbing Code, Table 308.5 — Hanger Spacing, digit-verified row-for-row across a municipal reproduction of the 2009 IPC table (McPherson, KS handout) and the state-adopted Alabama Plumbing Code 2015 (IPC) via the UpCodes public viewer; sampled rows additionally match ICC’s public 2024 IPC text (values unchanged across these editions)