Footnotes from the code: for several materials 2 in and smaller, a guide is required midway between vertical supports to prevent movement perpendicular to the pipe axis; cast-iron horizontal spacing may increase to 10 ft where 10-ft pipe lengths are installed.

Pipe support spacing is the maximum distance permitted or recommended between hangers, clamps, straps, guides, or other supports carrying or restraining a pipe run. Spacing affects sag, alignment, slope, joint stress, vibration, thermal movement, pipe stress, and hanger loads.

One material can have 4 ft horizontal spacing but 10 ft vertical spacing, since the governing physical concern is different in each orientation.

The 2024 IRC Table P2605.1 explicitly lists maximum horizontal and vertical support spacing by piping material for the residential plumbing context. Always check the locally adopted code edition and amendments, since some U.S. jurisdictions use the IRC, IPC, UPC, or state and city amendments that may differ from the base code values shown here.

The 2024 IPC requires piping to be supported in accordance with Table 308.5, with an exception for systems specifically engineered for expansion and contraction. The IPC Table 308.5 values match the IRC Table P2605.1 values for the materials covered in this chart, giving this page relevance for both residential and broader commercial plumbing audiences.

This is a plumbing-code support interval, not a universal engineered process-piping span for every size, schedule, temperature, or service. Do not treat 12 ft as an engineered maximum span for hot steam, heavy valves, large process piping, or vibration-sensitive systems. See the Black Iron Pipe Size Chart, Pipe Weight Chart, and Pipe Schedule Chart for related dimensional and weight data.

The general IRC support category for steel pipe gives 12 ft horizontal and 15 ft vertical spacing. Galvanizing does not create a completely separate support-spacing family; it is a surface coating applied to the same underlying steel pipe dimensional system. See the Galvanized Pipe Size Chart for the complete galvanized dimensional reference.

The Copper Development Association separately gives practical guidance for drawn copper tube at approximately 8-ft horizontal intervals for 1 in and smaller and 10 ft for larger sizes, unless applicable plumbing-code requirements say otherwise, with vertical runs generally supported about every 10 ft per story. Code tables and manufacturer or industry recommendations are not always numerically identical; use whichever requirement is applicable to the specific project. See the Copper Pipe Size Chart for complete copper dimensional data.

Manufacturer technical guidance independently confirms that common plumbing codes generally limit ABS and PVC horizontal hanger spacing to 4 ft, while emphasizing that support must also consider operating temperature, fittings, and local code requirements. See the PVC Pipe Size Chart for complete dimensional data.

Manufacturer guidance independently confirms this same general code pattern: 3 ft for 1 in and smaller and 4 ft for 1-1/4 in and larger. Temperature-sensitive plastic systems may require manufacturer-specific closer spacing beyond this base code value.

Uponor’s bare PEX-a installation guidance uses the same IPC-aligned base spacing: 32 in for 1 in and smaller, and up to 48 in for 1-1/4 in and larger under some codes, with vertical support approximately every 5 ft. Where code, listing, and manufacturer instructions differ, the actual project must satisfy the applicable adopted code and listed installation requirements. See the PEX Pipe Size Chart for complete PEX dimensional data.

Uponor’s proprietary PEX-a Pipe Support can increase horizontal support spacing to as much as 8 ft when installed in accordance with its system requirements. For higher temperature-differential applications, clamps or fixed points are also required per the manufacturer’s instructions, with clamping typically specified at a maximum on-center interval to control thermal expansion. This demonstrates that “PEX spacing equals 32 inches” is not universally true for every engineered or listed PEX support system.

Manufacturer technical guidance likewise confirms common plumbing-code support at 4 ft for both ABS and PVC.

The 2024 IRC also includes manufacturer-based provisions and footnotes for these composite and polypropylene systems, allowing spacing to be increased to the manufacturer’s installation requirements based on maximum operating temperature design or incorporation of pipe/tube supports per the manufacturer’s instructions.

Do not extrapolate this drainage-system value to all stainless process piping; process and industrial stainless systems have their own engineering-based support requirements.

Support spacing depends partly on elastic stiffness, creep behavior, temperature sensitivity, pipe or tube geometry, weight, and joint system. Rigid steel can typically span farther than flexible thermoplastic tubing in ordinary plumbing applications, which is why steel allows 12 ft while PEX 1 in and smaller allows only 32 in under the same code table.

Examples from the code include copper tubing changing spacing at the 1-1/4 to 1-1/2 in transition, PEX changing at the 1 to 1-1/4 in transition, CPVC changing at the same threshold, and PE-RT and polypropylene changing likewise. For engineered metal piping, size also affects pipe weight, bending stiffness, support load, and sag behavior in ways not captured by the plumbing code table.

Support selection must consider pipe self-weight, contained fluid, insulation, and valves or fittings. The IPC requires hangers and supports to support the piping and its contents, and its general support provisions address approved support materials and structural attachment. See the Pipe Weight Chart for empty and filled pipe weight data.

A pipe support system is normally concerned with the operating or load condition, not just empty pipe. Large-diameter, fluid-filled pipe can weigh substantially more than empty pipe. See the Pipe Volume Chart and Pipe Weight Chart for the volume and weight calculations behind this consideration.

Manufacturer technical guidance states that support spacing for horizontal plastic systems must consider the maximum operating temperature, publishing recommended spacing according to size, schedule, and operating temperature. Higher temperature reduces thermoplastic stiffness, increases sag, and increases thermal movement, requiring closer supports in many cases. A room-temperature spacing table cannot automatically be used for hot CPVC or PVC process piping.

The IPC expressly allows an exception where expansion and contraction support intervals are established by engineered design. A hanger carries weight, a guide directs movement, an anchor restrains movement, and an expansion loop or offset accommodates growth. For PEX, manufacturer support systems can use special clamps and fixed points to control movement in higher temperature-differential applications.

Heavy items such as large valves, strainers, flanges, backflow preventers, pumps, and meters introduce concentrated loads. Manufacturer technical guidance recommends supporting changes in direction close to fittings to avoid excessive stresses, and notes that heavy valves and fittings affect required spacing.

Elbows and tees can need closer support due to torsion, thermal movement, weight, and branch loads. Manufacturer guidance explicitly recommends supporting changes in direction as close as practical to the fitting.

Support must maintain required slope, alignment, and drainage grade. Sagging between supports can create bellies, standing water, or grade reversal. Therefore maximum hanger spacing may still be too wide if it fails to preserve slope in a real installation, particularly relevant for PVC DWV, ABS, and cast iron drainage piping.

The 2024 IRC footnote requires, for several materials 2 in and smaller, a guide installed midway between required vertical supports to prevent movement perpendicular to the pipe axis. Vertical spacing described as “support every 10 ft” does not necessarily mean the pipe needs no intermediate guiding within that interval.

Support type selection depends on expected movement, load, pipe material, temperature, and insulation, not on spacing distance alone.

The IPC requires approved hanger and support materials that do not promote harmful galvanic action. Manufacturer guidance for plastic pipe also warns that supports must not compress, distort, cut, or abrade the piping. Copper and steel contact considerations, broad-bearing plastic support requirements, and abrasion protection at support points all matter for long-term piping performance.

ANSI/MSS SP-58-2025 is now the current revision, superseding the older SP-58-2018 edition. It establishes an industry-accepted basis for the materials, design, manufacture, selection, application, and installation of pipe hangers and supports across service temperatures.

ASME’s B31.3 process piping design guidance treats pipe support design as involving pipe support stresses, loads on supporting elements, standard and special supports, load ratings, and support reactions. Do not use the IRC or IPC quick table as an engineered process-piping span table.

Gravity hangers and supports are not automatically seismic bracing. The IPC support provisions separately address seismic support where earthquake loads apply. Gravity support carries weight; seismic restraint limits earthquake-induced movement. This chart does not provide simplified seismic spacing values, since seismic bracing requires project-specific engineering based on applicable seismic design category and local requirements.