Pipe Cutting and Joining

Pipe Cutting and Joining

Reference text for the pipe cutting and joining area. Every rule below is written from the printed line

of the 2024 International Plumbing Code (IPC 2024) that carries it, and each rule names the section it

comes from. Where the printed line does not state a value, no value is stated here. The material comes

from the water-side joints of Chapter 6 and the drainage-side joints of Chapter 7, because the same

craft operations — cutting square, reaming, cleaning, and making up the joint — are regulated twice,

once for each side of the system.

1. What governs a joint

The water supply chapter's material provisions begin with the ground the pipe is buried in: installing a

water service or water distribution pipe is prohibited in soil and ground water contaminated with

solvents, fuels, organic compounds or other detrimental materials causing permeation, corrosion,

degradation or structural failure of the piping material; where detrimental conditions are suspected a

chemical analysis of the soil and ground water is required, and where they exist, approved alternative

materials or routing must be used (IPC 2024, 605.1).

What the joint may contain is limited on the lead side. Pipe and pipe fittings, including valves and

faucets, used in the water supply system may have not more than 8 percent lead content (IPC 2024,

605.2), and pipe, pipe fittings, joints, valves, faucets and fixture fittings used to supply water for

drinking or cooking must comply with NSF 372 and have a weighted average lead content of 0.25 percent or

less (IPC 2024, 605.2.1). On the drainage side, Chapter 7's joint section contains provisions applicable

to joints specific to sanitary drainage piping (IPC 2024, 705.1).

Two lists of joints that may not be made bracket the area. On the water side, the prohibited joints and

connections are cement or concrete joints, joints made with fittings not approved for the specific

installation, solvent-cement joints between different types of plastic pipe, and saddle-type fittings

(IPC 2024, 605.9). On the drainage side they are cement or concrete joints, mastic or hot-pour

bituminous joints, joints made with fittings not approved for the specific installation, joints between

different diameter pipes made with elastomeric rolling O-rings, solvent-cement joints between different

types of plastic pipe except where the plastic-to-plastic provision allows a single such joint, and

saddle-type fittings (IPC 2024, 707.1). A saddle fitting is a joint made through the wall of a pipe: it

is prohibited on both sides of the system.

2. Cutting the pipe end

A cut is part of the joint, and the code says what the cut has to look like. Polyethylene pipe must be

cut square with a cutter designed for plastic pipe; except where joined by heat fusion, pipe ends must be

chamfered to remove sharp edges; kinked pipe may not be installed; the minimum pipe bending radius must

be not less than 30 pipe diameters, or the minimum coil radius, whichever is greater; piping may not be

bent beyond straightening of the curvature of the coil; bends are prohibited within 10 pipe diameters of

any fitting or valve; and stiffener inserts installed with compression-type couplings and fittings may

not extend beyond the clamp or nut of the coupling or fitting (IPC 2024, 605.18.4).

Cut tube ends are reamed to the full inside diameter of the tube end — a requirement printed in each of

the copper joining provisions that follows a cut — for copper pipe solder joints (IPC 2024, 605.12.3),

copper tubing press-connect joints (IPC 2024, 605.13.5) and copper tubing solder joints (IPC 2024,

605.13.6), and on the drainage side for copper pipe solder joints (IPC 2024, 705.5.3) and copper tubing

solder joints (IPC 2024, 705.6.3). Reaming removes the burr that would otherwise sit in the flow path

and, on a soldered joint, keep the tube from seating.

Where a tube end is to be flared, the flare is made with a tool designed for that operation — with no

other method offered. That is stated for copper tubing flared joints on the water side (IPC 2024,

605.13.2), for PEX flared pipe ends (IPC 2024, 605.16.1), and for polyethylene flared joints where the

pipe manufacturer so indicates (IPC 2024, 605.18.1).

Where pipe is to be threaded, the wall has to be able to take it: for ABS (IPC 2024, 605.10.3), CPVC

(IPC 2024, 605.14.3), PVC on the water side (IPC 2024, 605.21.4) and PVC on the drainage side (IPC 2024,

705.10.3) the provision is the same — the pipe must have a wall thickness of not less than Schedule 80,

threads must be made with dies specifically designed for plastic pipe, and approved thread lubricant or

tape is applied on the male threads only. Threaded ABS pipe on the drainage side is held to the same

thread standard and the same male-threads-only rule (IPC 2024, 705.2.3).

A mechanically formed tee fitting adds its own cutting requirement: mechanically extracted outlets must

have a height not less than three times the thickness of the branch tube wall (IPC 2024, 605.5.1), the

branch tube may not restrict flow in the run tube, a dimple serving as a depth stop must be formed in the

branch tube so that penetration into the collar is of the correct depth, a second dimple must be placed

1/4 inch (6.4 mm) above the first so the depth can be inspected, and the dimples must be aligned with the

tube run (IPC 2024, 605.5.1.1).

3. Preparing the surfaces

Three preparation rules recur across the joining methods, and they are the ones an inspector looks for

before the joint is made.

Surfaces clean and free from moisture. This is printed for ABS solvent cementing (IPC 2024, 605.10.2),

for CPVC solvent cementing (IPC 2024, 605.14.2), for CPVC/AL/CPVC solvent cementing (IPC 2024, 605.15.2),

for PVC solvent cementing on the water side (IPC 2024, 605.21.3) and on the drainage side (IPC 2024,

705.2.2 and 705.10.2), and for heat-fusion joints in polyethylene (IPC 2024, 605.18.2), polypropylene

(IPC 2024, 605.19.1), polyethylene drainage pipe (IPC 2024, 705.12.1), polyolefin (IPC 2024, 705.13.1)

and polyvinylidene fluoride (IPC 2024, 705.14.1). A wet joint surface is a defective joint surface.

Surfaces cleaned, with flux where required. The brazed joint provisions say the joint surfaces must be

cleaned and an approved flux applied where required (IPC 2024, 605.12.1, 605.13.1, 705.5.1 and 705.6.1),

and the welded provisions say the joint surfaces must be cleaned before welding (IPC 2024, 605.12.5,

605.22.2 and 705.5.5).

The joint made while the cement is wet or fluid. Solvent-cement joints are made while the cement is wet

(IPC 2024, 605.10.2, 705.2.2 and 705.10.2), while the cement is fluid where the CPVC manufacturer's

instructions require a primer (IPC 2024, 605.14.2), and while the cement is wet for CPVC/AL/CPVC

(IPC 2024, 605.15.2). Heat-fusion joints are the mirror image: the surfaces are heated to melt

temperature and joined, and the joint must be left undisturbed until cool (IPC 2024, 605.18.2, 605.19.1,

705.12.1, 705.13.1 and 705.14.1).

4. Soldered joints

For copper pipe and copper tubing, the solder joint provision is substantially the same on the water and

drainage sides: joints are made in accordance with the methods of ASTM B828; cut tube ends are reamed to

the full inside diameter; joint surfaces are cleaned; a flux conforming to ASTM B813 is applied; and the

joint is soldered with a solder conforming to ASTM B32 (IPC 2024, 605.12.3, 605.13.6, 705.5.3 and

705.6.3).

The water-side provisions add the drinking-water conditions. The joining of water supply piping must be

made with lead-free solder and fluxes, where "lead free" means a chemical composition equal to or less

than 0.2 percent lead, and solder and flux joining pipe or fittings intended to supply drinking water

must conform to NSF 61 (IPC 2024, 605.12.3 and 605.13.6).

5. Brazed joints

Brazing appears in four places — copper or copper-alloy pipe (IPC 2024, 605.12.1), copper or copper-alloy

tubing (IPC 2024, 605.13.1), copper or copper-alloy pipe on the drainage side (IPC 2024, 705.5.1) and

copper or copper-alloy tubing on the drainage side (IPC 2024, 705.6.1) — and each is written the same

way: the joint surfaces are cleaned, an approved flux is applied where required, and the joint is brazed

with a filler metal conforming to AWS A5.8.

A mechanically formed tee fitting is brazed in accordance with the copper brazed joint provision the

code names (IPC 2024, 605.5.1.2).

6. Welded joints

Copper or copper-alloy pipe joints may be welded: the joint surfaces are cleaned and the joint is welded

with an approved filler metal (IPC 2024, 605.12.5), and the same provision applies to copper pipe on the

drainage side (IPC 2024, 705.5.5). Stainless steel pipe is welded either autogenously or with an approved

filler metal as referenced in ASTM A312, after the joint surfaces are cleaned (IPC 2024, 605.22.2).

7. Threaded joints

Threads conform to ASME B1.20.1 in every threaded provision the code prints. On the water side that is

copper or copper-alloy pipe (IPC 2024, 605.12.4), galvanized steel pipe (IPC 2024, 605.17.1), ABS

(IPC 2024, 605.10.3), CPVC (IPC 2024, 605.14.3) and PVC (IPC 2024, 605.21.4). On the drainage side it is

the same standard for ABS (IPC 2024, 705.2.3), PVC (IPC 2024, 705.10.3), copper or copper-alloy pipe

(IPC 2024, 705.5.4) and galvanized steel pipe (IPC 2024, 705.8.1).

The sealant rule is uniform: pipe-joint compound or tape is applied on the male threads only (IPC 2024,

605.12.4, 605.17.1, 705.5.4 and 705.8.1), and for the plastic materials, approved thread lubricant or

tape on the male threads only (IPC 2024, 605.10.3, 605.14.3, 605.21.4, 705.2.3 and 705.10.3). On the

plastic materials the pressure consequence is stated as well: the pressure rating of threaded pipe must

be reduced by 50 percent, and thread-by-socket molded fittings are permitted (IPC 2024, 605.14.3 and

605.21.4). Where threaded joints are used in a metal drainage system, the fittings must be of the

recessed drainage type and must not present ledges, shoulders or reductions capable of retarding or

obstructing flow (IPC 2024, 706.2).

8. Solvent-cemented joints

Solvent cementing is regulated material by material, and the cement standard, the primer and the joint

method differ between them.

while the cement is wet, and it is made in accordance with ASTM D2235; solvent-cement joints are

permitted above or below ground (IPC 2024, 605.10.2). On the drainage side the cement may conform to

ASTM D2235 or CSA B181.1, and the joint may be made in accordance with ASTM D2235, ASTM D2661,

ASTM F628 or CSA B181.1 (IPC 2024, 705.2.2).

instructions require a primer, the primer is applied to the joint surfaces and a solvent cement orange

in color and conforming to ASTM F493 is applied; the joint is made in accordance with ASTM D2855 and

while the cement is fluid. Where the instructions allow a one-step solvent cement, yellow or green in

color and conforming to ASTM F493, no primer is applied and the joint is made in accordance with

ASTM F3328 and while the cement is wet (IPC 2024, 605.14.2). The joints are permitted above or below

ground.

ASTM F493, is applied to the joint surfaces; the joint is made while the cement is wet and in

accordance with ASTM D2855, and solvent-cement joints are permitted above or below ground (IPC 2024,

605.15.2). The exception excuses the primer only where all of the stated conditions hold at once: the

cement is third-party certified as conforming to ASTM F493, it is yellow in color, it is used only for

joining 1/2-inch (12.7 mm) through 2-inch-diameter (51 mm) CPVC/AL/CPVC pipe and CPVC fittings, the

fittings are manufactured in accordance with ASTM D2846, and the joint is made in accordance with

ASTM F3328 (IPC 2024, 605.15.2).

conforming to ASTM D2564 or CSA B137.3 is applied to all joint surfaces; the joint is made while the

cement is wet and in accordance with ASTM D2855; and solvent-cement joints are permitted above or below

ground (IPC 2024, 605.21.3). On the drainage side the cement may also conform to CSA B181.2 or

CSA B182.1 (IPC 2024, 705.10.2). The primer is excused only where the cement is third-party certified

as conforming to ASTM D2564, it is used only for joining PVC drain, waste and vent pipe and fittings in

nonpressure applications in sizes up to and including 4 inches (102 mm) in diameter, and the joint is

made in accordance with ASTM F3328 (IPC 2024, 705.10.2). (A state may amend the wording of that

exception; the amendment is state material and is not written here.)

ABS and PVC pipe at the end of a building drainage pipe and the beginning of a building sewer pipe,

using a solvent cement complying with ASTM D3138 (IPC 2024, 705.16.4).

9. Mechanical joints, coupling by coupling

A mechanical joint is only as good as its seal, and each material names the seal it accepts.

are installed only in underground systems unless otherwise approved, in accordance with the

manufacturer's instructions (IPC 2024, 605.10.1). On drainage pipes the seal conforms to ASTM C1173,

ASTM D3212 or CSA B602, again underground only unless otherwise approved (IPC 2024, 705.2.1). Above

ground, a coupling used to connect ABS pipe to ABS pipe must be of the shielded type and marked by the

manufacturer as recommended for the application (IPC 2024, 705.2.4).

not be installed in above-ground systems unless otherwise approved (IPC 2024, 605.21.1). On drainage

pipe the seal conforms to ASTM C1173, ASTM D3212 or CSA B602, with the same above-ground prohibition

(IPC 2024, 705.10.1); above ground, PVC-to-PVC couplings must be of the shielded type and marked for

the application (IPC 2024, 705.10.5).

ASTM C1173, ASTM D3212 or CSA B602 (IPC 2024, 705.12.2); on the water side mechanical joints are

installed in accordance with the manufacturer's instructions (IPC 2024, 605.18.3).

must comply with the standards of the pipe fittings table; and the tubing must be factory marked with

the standards for the fittings the tubing manufacturer specifies for use with it (IPC 2024, 605.16.2).

instructions, and the fittings must be installed in accordance with the manufacturer's instructions as

well (IPC 2024, 605.20.1).

must comply with the standards of the pipe fittings table, and the tubing must be factory marked with

the applicable fitting standards (IPC 2024, 605.24.1).

accordance with the manufacturer's instructions (IPC 2024, 605.19.2 and 705.14.2).

the manufacturer's instructions (IPC 2024, 605.22.1 and 605.22.3).

manufacturer's instructions (IPC 2024, 605.17.2 and 705.8.2).

the manufacturer's instructions (IPC 2024, 605.11).

10. Grooved and shouldered joints

A grooved or shouldered mechanical joint must comply with ASTM F1476, be made with an approved elastomeric

seal, and be installed in accordance with the manufacturer's instructions; such joints may be exposed or

concealed. The provision is printed for copper tubing (IPC 2024, 605.13.3), for galvanized steel pipe

(IPC 2024, 605.17.3), for PVC on the water side (IPC 2024, 605.21.2) and for stainless steel pipe

(IPC 2024, 605.22.3).

11. Press-connect and push-fit joints

Press-connect joints must conform to a standard indicated in the pipe fittings table and be installed in

accordance with the manufacturer's instructions; the cut tube end is reamed to the full inside diameter,

the joint surfaces are cleaned, the tube is fully inserted into the fitting, and the joint is pressed with

a tool certified by the manufacturer (IPC 2024, 605.13.5).

Push-fit joints conform to ASSE 1061 and are installed in accordance with the manufacturer's instructions

for copper tubing (IPC 2024, 605.13.7), CPVC (IPC 2024, 605.14.4) and PEX (IPC 2024, 605.16.3). On the

drainage side, push-fit DWV fittings must be listed and labeled to ASME A112.4.4 and installed in

accordance with the manufacturer's instructions (IPC 2024, 705.2.5), and push-fit joints must conform to

ASME A112.4.4 (IPC 2024, 705.10.4).

12. Heat fusion and fusion-type joints

Polyethylene joints may be heat-fused where the surfaces are clean and free from moisture, heated to melt

temperature and joined, the joint left undisturbed until cool, and the work done in accordance with

ASTM D2657 (IPC 2024, 605.18.2). On the drainage side, joints between polyethylene pipe and fittings must

be underground, and the heat-fusion method uses tools specifically designed for the operation, in

accordance with ASTM D2657 and the manufacturer's instructions (IPC 2024, 705.12.1).

Polypropylene and polyvinylidene fluoride heat-fusion joints are installed with socket-type heat-fused

fittings, butt-fusion fittings or electrofusion fittings as the material allows; the surfaces are clean

and free from moisture; the joint is left undisturbed until cool; and the work follows the standard the

material names — ASTM F2389 for polypropylene (IPC 2024, 605.19.1) and ASTM F1673 for polyvinylidene

fluoride (IPC 2024, 705.14.1). Polyolefin heat-fusion joints use socket-type or electrofusion fittings

and follow ASTM F1412 or CSA B181.3 (IPC 2024, 705.13.1).

13. Cast iron, lead, glass, concrete and clay: the drainage methods

is poured in one operation to a depth of not less than 1 inch (25 mm); the lead may not recede more than

1/8 inch (3.2 mm) below the rim of the hub and must be caulked tight; paint, varnish or other coatings

are not permitted on the jointing material until the joint has been tested and approved; and

acid-resistant rope and acidproof cement are permitted (IPC 2024, 705.3.1).

and be tested to ASTM C1563, and must be compressed when the pipe is fully inserted (IPC 2024, 705.3.2).

a metallic shield complying with CISPI 310, ASTM C1277 or ASTM C1540; the sleeve conforms to ASTM C564

or CSA B602 and must be provided with a center stop; and the coupling is installed in accordance with

the manufacturer's instructions (IPC 2024, 705.3.3).

CSA B602 (IPC 2024, 705.4).

CSA B602 (IPC 2024, 705.11).

the thickness of the lead being joined and a filler metal of the same material as the pipe (IPC 2024,

705.9.1). Wiped joints must be fully wiped, with an exposed surface on each side of the joint of not

less than 3/4 inch (19.1 mm), and the joint must be not less than 3/8 inch (9.5 mm) thick at the

thickest point (IPC 2024, 705.9.2).

stainless steel coupling with contoured acid-resistant elastomeric compression ring and a fluorocarbon

polymer inner seal ring, or with caulked joints: packed with oakum or hemp, filled with molten lead not

less than 1 inch (25 mm) deep, not receding more than 1/8 inch (3.2 mm) below the rim of the hub,

caulked tight, with no paint, varnish or other coating on the jointing material before the joint is

tested and approved, and with acid-resistant rope and acidproof cement permitted (IPC 2024, 705.7).

with Table 705.18, and soldering bushings of copper or copper alloy in accordance with Table 705.19

(IPC 2024, 705.18 and 705.19).

705.20).

14. Joints between different materials

Joining two different materials is its own subject, because the joint has to be made of something that

suits both.

Water side. Joints between different piping materials are made with a mechanical joint of the compression

or mechanical-sealing type, or as the provisions for particular pairs direct; connectors and adapters

must have an elastomeric seal conforming to ASTM F477, and the joints are installed in accordance with

the manufacturer's instructions (IPC 2024, 605.23). Copper or copper-alloy tubing to galvanized steel pipe

is made with a copper-alloy or dielectric fitting or a dielectric union conforming to ASSE 1079, with the

copper soldered to the fitting and the fitting screwed to the threaded pipe (IPC 2024, 605.23.1). Plastic

pipe or tubing to other piping material is made with approved adapters or transition fittings (IPC 2024,

605.23.2). Stainless steel to different piping materials is made with a mechanical joint of the

compression or mechanical sealing type, or with a dielectric fitting or dielectric union conforming to

ASSE 1079 (IPC 2024, 605.23.3).

Drainage side. Joints between different piping materials are made with a mechanical joint conforming to

ASTM C1173, ASTM C1460 or ASTM C1461, with approved connectors and adapters having an elastomeric seal

conforming to the listed standards, or as the provisions for particular pairs direct; joints between

glass pipe and other materials are made with adapters having a TFE seal; and all such joints are installed

in accordance with the manufacturer's instructions (IPC 2024, 705.16). The particular pairs: copper pipe

or tubing to cast-iron hub pipe, with a copper or copper-alloy ferrule or compression joint, the copper

soldered to the ferrule and the ferrule joined to the hub by a caulked joint or a mechanical compression

joint (IPC 2024, 705.16.1); copper or copper-alloy pipe or tubing to galvanized steel pipe, with a

copper-alloy or dielectric fitting (IPC 2024, 705.16.2); cast iron to galvanized steel, by caulked or

threaded joints or with an approved adapter fitting (IPC 2024, 705.16.3); plastic pipe or tubing to other

piping material, with an approved adapter fitting, with the single ABS-to-PVC solvent-cement joint of

ASTM D3138 permitted as described above, and with plastic-to-cast-iron-hub joints made by a caulked joint

or a mechanical compression joint (IPC 2024, 705.16.4); lead pipe to other piping material, by a wiped

joint to a caulking ferrule, soldering nipple or bushing, or with an approved adapter fitting (IPC 2024,

705.16.5); borosilicate glass to other materials, with adapters having a TFE seal (IPC 2024, 705.16.6);

and stainless steel drainage systems to other materials, with approved mechanical couplings (IPC 2024,

705.16.7).

One further paired-material rule sits on the water side: a dual check-valve-type backflow preventer

installed on the water supply system must comply with ASSE 1024 or CSA B64.6 (IPC 2024, 605.3.1).

15. The fittings a joint feeds: connections and changes in direction

A joint is made to hold a fitting, and the fitting rules decide what may be used. Connections and changes

in direction of the sanitary drainage system must be made with approved drainage fittings, and

connections between drainage piping and fixtures must conform to the code's fixture connection provisions

(IPC 2024, 706.1).

Fittings may not have ledges, shoulders or reductions capable of retarding or obstructing flow in the

piping, and threaded drainage pipe fittings must be of the recessed drainage type; that requirement does

not apply to tubular waste fittings used to convey vertical flow upstream of the trap seal liquid level of

a fixture trap (IPC 2024, 706.2).

Fittings must be installed to guide sewage and waste in the direction of flow, and changes in direction

must be made by fittings installed in accordance with Table 706.3; a change in direction by combination

fittings, side inlets or increasers must be installed in accordance with that table based on the pattern of

flow created by the fitting. Double sanitary tee patterns may not receive the discharge of back-to-back

water closets and fixtures or appliances with pumping action discharge, unless the horizontal developed

length between the outlet of the water closet and the connection to the double sanitary tee pattern is

18 inches (457 mm) or greater (IPC 2024, 706.3). Table 706.3 lists by fitting pattern — sixteenth bend,

eighth bend, sixth bend, quarter bend, short sweep, long sweep, sanitary tee, wye, and combination wye and

eighth bend — which patterns are permitted for a horizontal to vertical, a vertical to horizontal and a

horizontal to horizontal change, with footnotes limiting the quarter bend and short sweep to a 2-inch or

smaller fixture drain in the columns where the footnote applies (IPC 2024, Table 706.3).

Heel-inlet quarter bends are an acceptable means of connection except where the quarter bend serves a

water closet, and a low-heel inlet may not be used as a wet-vented connection; side-inlet quarter bends

are acceptable for drainage, wet venting and stack venting arrangements (IPC 2024, 706.4).

16. The joining methods, material by material

17. Reading the area: the sequence a joint is checked in

lists answer first (IPC 2024, 605.9 and 707.1).

where the joint is soldered or press-connected, chamfered where it is not heat-fused, flared with the

tool designed for it, threaded only at the required wall thickness, and not kinked or bent inside the

prohibited radius (IPC 2024, 605.18.4, 605.12.3 and 605.13.5).

with flux where the brazed joint requires it (IPC 2024, 605.10.2, 605.18.2 and 605.12.1).

required — purple primer of ASTM F656 for PVC, orange cement of ASTM F493 for CPVC — with the

consumable left off only where the exception's conditions all hold (IPC 2024, 605.21.3, 605.14.2 and

705.10.2).

by the manufacturer for a press-connect joint, tools designed for the operation for flared and

heat-fused joints — and left undisturbed until cool where fusion is used (IPC 2024, 605.13.5, 605.16.1

and 605.18.2).

reduction to obstruct it, and is it the permitted pattern for that change in direction (IPC 2024,

706.2, 706.3 and Table 706.3)?