8.3 Hangers, Supports & Protection of Piping (SPS 382.60)

Materials and strength (SPS 382.60 (1))

• Hangers, anchors and supports must carry the piping and its contents. Drain piping is considered full of water for this purpose.
• Underground piers for pipe support must be concrete, masonry, plastic or pressure-treated wood.
• Hangers and straps must be of a compatible material that reduces galvanic action, and may not distort, cut or abrade the pipe. Bare steel strap on copper is the classic violation.

Installation (SPS 382.60 (2))

1. Hangers and anchors are attached securely to the building structure at intervals no greater than Table 382.60. PVC used for venting may be supported every 5 feet horizontally.
2. The connection of drain piping to a fixture or appliance counts as a point of support.
3. Hubless pipe installed horizontally must be supported within 24 inches on each side of a joint, unless the joint has an alignment retaining shield.
4. Hangers may not be attached with wood plugs.
5. Shower valves and the piping from the valve to the showerhead outlet must be securely attached to the structure.

Table 382.60 support spacing

"Mid-story guide" (CPVC vertical) means a guide is also required midway between floors.

Worked examples

PVC drain. A 60-foot horizontal run of 3-inch PVC drain needs supports at no more than 4-foot intervals: 60 / 4 = 15 spaces, so about 16 supports counting both ends. Where the drain connects to a fixture, that connection counts as one support point. If the same pipe were a vent, 5-foot spacing would need about 13 supports.

Cast iron. No-hub cast iron in 10-foot lengths may be hung every 10 feet. But each horizontal no-hub joint without an alignment shield still needs a support within 24 inches on each side. In practice that means a hanger near every coupling.

PEX. A 40-foot horizontal PEX run needs supports no more than 2 feet 8 inches (32 inches) apart: 480 inches / 32 = 15 spaces, so about 16 supports. That is why PEX is often run in continuous channel or laid on joists. Continuous support satisfies the spacing limit.

Copper. In a 1-inch copper tube riser through a three-story building, Table 382.60 requires vertical support at least every 10 feet. Horizontally the same 1-inch tube needs support every 6 feet; a 2-inch tube, every 10 feet.

Related protection rules

Rough-in inspection checklist for supports

Before calling for a rough-in inspection, walk the job with the table in hand:

1. Measure the longest unsupported horizontal run of each material and compare it to Table 382.60. Remember the fixture connection counts as one support.
2. Check every horizontal no-hub coupling for a hanger within 24 inches on each side, or an alignment shield.
3. Confirm that hangers are fastened to structure (not to other piping, ductwork or wood plugs), and that straps match the pipe material.
4. Look at risers: vertical supports at the table spacing, and mid-story guides on CPVC.
5. Verify that shower valves and the piping to the showerhead are rigidly fastened, and that nail plates protect pipe within 1 inch of framing edges.

Exam traps

• Answering "10 feet" for horizontal cast iron: the base value is 5 feet, rising to 10 only with 10-foot lengths.
• Confusing copper pipe (12 ft) with copper tubing (6 or 10 ft).
• Forgetting that drain piping counts as full of water when sizing hangers.