BOABC Plumbing Level I cheat sheet

Uniform Plumbing Code (UPC) and International Plumbing Code (IPC) are the two model codes most U.S. jurisdictions adopt; local amendments supersede the model text.

A permit is required for new water, waste, and vent piping, fixture replacement that alters rough-in, and water heater replacement; minor repairs such as washer replacement do not require one.

Potable water supply piping must maintain minimum 12-inch horizontal separation from sewer and drain pipe, and 12 inches above a sewer line when crossing.

Water-distribution pipe in a trench must be separated from a building sewer by at least 12 inches horizontally and must cross at least 12 inches above the sewer.

A backflow prevention device is required at every connection between potable water and a nonpotable system, including irrigation, boiler feed, and fire-sprinkler lines.

Each fixture must be individually protected by a trap; a single trap may serve a set of fixtures only where the code expressly permits it (e.g., a three-compartment sink with a continuous waste).

Vent stack must terminate at least 6 inches above the roof surface and at least 10 feet from any operable window, door, or air intake.

Water heater temperature-and-pressure relief valve discharge must terminate not more than 6 inches above the floor and not less than 6 inches above grade.

Verify fixture-unit counts against the fixture-unit table for the building occupancy before approving drain sizing.

Check that every fixture is shown with its trap, vent, and cleanout, and that vent distances from the trap weir comply with the adopted code.

Confirm slope: 1/4 inch per foot for 2-inch and smaller drains, 1/8 inch per foot for 3-inch and larger drains, unless the code specifies otherwise.

Review water-supply sizing using the demand-load method: total fixture units converted to gallons per minute, then compared against pipe capacity at the available pressure.

Confirm clearances: 15-inch minimum from centerline of a water closet to a side wall, 30-inch minimum clear width in front of fixtures.

Check that cleanouts are shown at the base of each stack, at changes in direction greater than 45 degrees, and at intervals not exceeding 100 feet.

Verify that the plan shows the building drain, building sewer, and the point of connection to the public sewer or private disposal system.

Confirm that plumbing plans match architectural, structural, and mechanical drawings for penetrations, chases, and equipment locations.

Rough-in inspection must occur after all piping is in place but before it is covered or concealed; the inspector verifies slope, support, and venting.

Water-supply system test: pressurize to at least the working pressure but not less than 100 psi for a minimum of 15 minutes with no drop in pressure.

Drain, waste, and vent test: either a water test with a 10-foot head at the lowest point or an air test at 5 psi for 15 minutes.

Building sewer test: water test with a minimum 10-foot head at the upstream end, or an air test at 5 psi.

Final inspection verifies fixtures, trim, water heater installation, gas piping, and that all prior corrections are complete.

Support spacing: horizontal cast-iron pipe at 5-foot intervals for 2-inch pipe, and 10-foot intervals for 4-inch and larger pipe.

Trap seal depth must be 2 to 4 inches; a trap more than 4 inches deep is a defect requiring correction.

Inspection records must document date, inspector, findings, and corrective action, and the file is retained per the jurisdiction's record-retention schedule.

An inspector's authority is limited to the adopted code and the permit scope; personal preference is not a basis for a correction notice.

Written correction notices must cite the code section, describe the condition, and specify the required action and reinspection process.

Field notes and photographs are contemporaneous records; they should be dated, identified by location, and retained with the inspection file.

Conflicts of interest include inspecting work by a family member, employer, or business associate; disclosure and reassignment are required.

Continuing education and code-update training are professional obligations; the adopted edition changes on a cycle set by the jurisdiction.

Communicate findings factually and without speculation about intent; describe the observed condition and the code requirement it violates.

When a contractor disputes a finding, the correct path is a written request for interpretation or appeal through the jurisdiction's established procedure.

Public officials must avoid the appearance of impropriety as well as actual conflicts; gifts, favors, and outside employment are governed by ethics rules.

Ex parte communications about a pending permit or appeal should be documented and disclosed to all parties.

Permit fees, inspection scheduling, and enforcement actions must be applied uniformly; selective enforcement is an ethics violation.

Records of inspections and permits are public records subject to disclosure law, with limited exceptions for security-sensitive information.

An appeal of an inspector's decision typically goes to the board of appeals within a set number of days, often 20 to 30, after the decision.

Administrative due process requires notice of the alleged violation, an opportunity to respond, and a written decision.

Inspectors must not perform design or contracting work within their jurisdiction; that separation prevents self-review and conflicts.

Revocation or suspension of a license or certification follows a defined disciplinary process with notice, hearing, and written findings.

Fixture unit values are assigned by fixture type in the code tables; a water closet is typically 3 or 4 fixture units depending on flush type.

A building drain carries waste from the building to the building sewer, which extends from the building to the public sewer or private disposal.

Horizontal wet venting requires the vent to be sized and sloped so that the vent remains above the water level in the drain it serves.

A cleanout is required at the base of every stack, at the junction of the building drain and building sewer, and at the end of every horizontal drain.

Air admittance valves may substitute for vent terminals only where the adopted code permits and the valve is accessible and listed for the use.

Gas piping must be tested at not less than 1.5 times the working pressure, with a minimum of 3 psi for a 10-minute test unless the code states otherwise.

A water heater must be installed with a temperature-and-pressure relief valve, a discharge pipe, and a pan where leakage would cause damage.

Check that the plan set includes a plumbing isometric or riser diagram showing stacks, vents, and fixture connections.

Verify that the fixture-unit total for each branch, stack, and building drain is shown and matches the sizing table.

Confirm that water-supply pipe sizes are shown for each branch and that the developed length and pressure loss are accounted for.

Review that the plan shows the location of the water service, meter, backflow preventer, and shutoff valves.

Check that the plan identifies the drainage fixture units and the corresponding drain sizes for each horizontal branch.

Confirm that the plan shows the vent terminal location relative to windows and air intakes on the roof plan.

Verify that the plan includes a schedule of fixtures with the manufacturer, model, and water-consumption rate for each fixture.

Rough-in inspection confirms that all piping is installed, supported, and sloped before concealment.

Final inspection confirms that fixtures, trim, and appliances are installed and operational.

Test records must show the test method, pressure or head, duration, and the result for each system tested.

Correction notices must identify the code section and the specific corrective action required.

Reinspection is scheduled after the correction is complete and documented by the contractor.

Inspection findings should be recorded in the field and entered into the permit record the same day.

Photographs taken during inspection should show the condition, the location, and a scale or reference where possible.

Stop-work orders are issued when work proceeds without a permit or when a condition presents an immediate hazard.

The inspector's role is to verify code compliance, not to direct the contractor's means or methods of construction.

Correction notices must be specific, code-referenced, and written in neutral language.

Field records should be contemporaneous and retained according to the jurisdiction's schedule.

Conflicts of interest must be disclosed and the inspector reassigned when a personal or financial relationship exists.

Continuing education keeps the inspector current with the adopted code edition and local amendments.

Disputes are resolved through the jurisdiction's written interpretation and appeal process, not through informal pressure.

Communication with contractors and owners should be factual, documented, and consistent across similar situations.

Ethics rules prohibit gifts, favors, and outside employment that could influence official decisions.

Ex parte communications about a pending permit or appeal must be disclosed to all parties.

Enforcement actions must be applied uniformly; selective enforcement is an ethics violation.

Inspection and permit records are public records subject to disclosure law with limited exceptions.

Appeals of an inspector's decision go to the board of appeals within a set period, often 20 to 30 days.

Due process requires notice, an opportunity to respond, and a written decision.

Inspectors must not perform design or contracting work within their jurisdiction.

License suspension or revocation follows a defined disciplinary process with notice, hearing, and written findings.