IN Plumber cheat sheet

The Indiana Plumbing Code is codified at 675 IAC 16 and is enforced locally by the authority having jurisdiction (AHJ).

A plumbing permit must be obtained before any installation, alteration, or repair begins; only minor repair work as defined by the AHJ is exempt.

Only a licensed plumbing contractor may obtain plumbing permits and contract to perform plumbing work.

Journeyman plumbers and apprentices must work under the direction of a licensed plumbing contractor.

Piping may not be concealed until the rough-in inspection is approved, and a final inspection is required before the system is placed in use.

The AHJ may issue a stop-work order, require removal of noncompliant work, and require re-inspection after corrections are made.

Materials and fixtures must be listed by a recognized testing agency and installed in accordance with their listing and the manufacturer's instructions.

Approved construction documents must be available on the job site for the inspector, and written appeals of AHJ decisions go to the local board of appeals.

One drainage fixture unit (dfu) equals 1 cubic foot per minute, approximately 7.5 gallons per minute, of fixture discharge.

One water supply fixture unit (wsfu) equals 1 gallon per minute of water demand and is the basis for sizing supply piping.

The building drain is the lowest pipe of the drainage system inside the building and extends 30 inches beyond the exterior wall, where it becomes the building sewer.

Horizontal drainage pipe 2-1/2 inches and smaller must slope at least 1/4 inch per foot; 3-inch and larger pipe at least 1/8 inch per foot.

Drainage pipe size may not be reduced in the direction of flow.

Developed length is the measured run of pipe plus an allowance for fittings and is the length used for pipe sizing.

Every fixture must be trapped and vented unless the code specifically permits an approved alternative arrangement.

A building that cannot drain by gravity to the public sewer requires a sewage ejector or ejector pump system.

Underground soil and waste piping must be bedded, supported, and tested before backfill.

Minimum residual pressure at fixtures is 15 psi during peak demand flow.

Fixture demand ratings include tank-type water closet 2.5 wsfu, flushometer water closet 10 wsfu, and lavatory 1 wsfu.

Supply pipe sizing uses total water supply fixture units combined with the developed length of the piping run.

Water service piping must be installed below the local frost depth or otherwise protected from freezing.

The water distribution system is tested with water at working pressure, but not less than 100 psi, for at least 15 minutes with no pressure drop.

A full-open shutoff valve is required on the building service and on the cold-water inlet to each water heater.

Potable water may not be directly connected to any nonpotable source; protection is by air gap or an approved backflow assembly.

Water hammer arrestors must be installed at quick-closing valves such as flushometer and solenoid valves.

Water piping must be supported at code intervals and protected where subject to corrosion or physical damage.

Horizontal drainage pipe 2-1/2 inches and smaller slopes at least 1/4 inch per foot; pipe 3 inches and larger slopes at least 1/8 inch per foot.

Cleanouts are required at the base of each stack, at the building drain, at changes of direction greater than 45 degrees, and at intervals not exceeding 100 feet.

Every fixture drain must be trapped; double trapping and S-traps are prohibited.

No fixture may discharge into another fixture below its flood level rim; waste must flow by gravity.

Vertical stacks must be supported at the base and at each floor level, and horizontal piping must be supported at code intervals.

A backwater valve is required where fixtures are installed below the level of the public sewer and subject to backflow.

Fixture unit tables determine branch, stack, and building drain sizes, and the building drain must be sized for the total dfu load.

Drainage and vent systems must be tested with water or air before the piping is concealed.

Every trap must be vented to open air, except where a combination waste-and-vent or other approved method is permitted.

Vent pipe must be at least 1-1/4 inches in diameter and may not be reduced in size in the direction of flow.

A vent terminal must extend at least 6 inches above the roof and be at least 10 feet from any window, door, or outdoor air intake, or 2 feet above it.

The stack vent is the extension of a soil or waste stack above the highest fixture branch served.

Wet venting is permitted only for specific fixture groupings and within the length limits set by the code.

Vent piping must slope back toward the drain so condensation and rainwater drain by gravity.

A vent may never carry waste or serve as a drain pipe.

Air admittance valves may be installed only where listed and approved, and they must remain accessible.

Trap seal depth must be at least 2 inches and not more than 4 inches.

Traps must be self-cleaning and accessible for cleaning; bell traps, bag traps, and crown-vented traps are prohibited.

Trap arm length is limited by the developed distance from the trap weir to the vent connection.

Grease interceptors are required for food service establishments and are sized in gallons per minute of fixture flow.

Oil, sand, and grit interceptors are required for garages, repair shops, and similar facilities.

Interceptors must be vented, accessible, and maintained in proper operating condition by the owner.

Corrosive or chemical wastes must be neutralized or treated before entering the drainage system.

A trap primer is required where a trap seal may evaporate, such as floor drains in unused areas.

Flow limits: water closet 1.6 gallons per flush, urinal 1.0 gallon per flush, showerhead 2.5 gpm at 80 psi, lavatory and kitchen faucets 2.2 gpm.

Fixtures must be listed, smooth, nonabsorbent, and installed in accordance with the manufacturer's instructions.

Every fixture must be provided with an approved water supply, waste outlet, trap, and vent.

Hose bibbs must be protected by an approved vacuum breaker.

Fixtures in public buildings must meet accessibility requirements for height, clearance, and operating force.

Water closets require a watertight seal and must be set level on a firm base.

Drinking fountains and beverage dispensing equipment require backflow protection.

Slip-joint connections are limited to the inlet side of traps and must be accessible.

The temperature and pressure relief valve must be set to open at 210 degrees Fahrenheit or 150 psi, and must be listed and sized for the heater.

Relief valve discharge piping must be full size, with no valves, threads, or traps, terminating within 6 inches of the floor or outdoors.

A drain pan is required where leakage would cause damage, and it must be piped to an approved drain point.

Closed potable systems require a thermal expansion tank or another approved means of pressure relief.

Water heaters must be installed per their listing, and combustion air and flue venting must comply with the code.

Ignition sources on heaters installed in garages must be elevated at least 18 inches above the floor.

Hot water delivered to fixtures for personal use should be limited to about 120 degrees Fahrenheit, with tempering valves for scald protection.

A shutoff valve is required on the cold-water inlet to the heater, and the heater must remain accessible for service.

Storm drainage must be entirely separate from the sanitary drainage system.

Roof drains, leaders, area drains, and downspouts must discharge to an approved storm outlet.

Roof drain and leader sizing is based on the roof area drained and the design rainfall intensity in inches per hour.

Storm drainage piping must be supported and must slope continuously to the point of discharge.

Roof drains require strainers, and large roofs require overflow drains or scuppers.

Storm water may never be discharged into a sanitary sewer or a private sewage disposal system.

Sump pumps and area drains receiving only groundwater or storm water may discharge to the storm system.

Separators or traps may be required for storm drains receiving runoff from parking and vehicle service areas.

An air gap must be at least twice the effective opening of the supply pipe and never less than 1 inch.

Reduced pressure zone assemblies protect against both backpressure and backsiphonage and are required for high hazard connections.

Double check valve assemblies protect against backpressure only and are used for low hazard connections.

Atmospheric and pressure vacuum breakers protect against backsiphonage at hose bibbs and similar outlets.

Testable backflow assemblies must be tested at installation and at least annually by a certified tester, with records provided to the water purveyor or AHJ.

Assemblies must be accessible, installed in the manufacturer's required orientation, and protected from freezing and flooding.

No plumbing connection may allow nonpotable water, chemicals, or gas to enter the potable water system.

Boiler feedwater, chemical injection, irrigation, and fire sprinkler connections each require the appropriate level of backflow protection.