Exam Cheat Sheet · Quick Reference
Virginia Master Plumber
Virginia · PSI Services Contractor
Verified, not estimated. Every figure below is drawn from the official exam structure we maintain — question counts, passing standard and topic weighting. Practice questions are grounded in the source law with statute citations. We omit any figure we can't verify rather than guess at it.
Total questions
80
Passing score
75%
Exam time
210 min
Administered by
PSI Services Contractor
Format
Reference materials allowed
Virginia State Portion 80 questions
Standards of Practice
3 Q · 4%
Prohibited acts and unlicensed contracting penaltiesGrounds for license denial, suspension, and revocationLicense reinstatement requirements and disciplinary authority during lapsed periodsContractor classification definitions and contract value thresholdsExemptions from contractor licensing requirementsWritten contract requirements for residential contractorsPlumbing work scope of practice and tradesman definitionsMaster vs. journeyman tradesman distinctions and qualifications
Standards of Conduct
2 Q · 2%
Prohibited acts and grounds for disciplinary actionTypes of disciplinary penalties available to the boardReporting convictions and license actions from other jurisdictionsAbandonment of contracted workMisrepresentation and false promises in the practice of the professionAiding or abetting unlicensed contractors and prohibited license-sharingFailure to obtain permits or required inspectionsPracticing outside licensed classification or specialty
Renewal and Reinstatement
2 Q · 2%
License expiration periods for plumber and tradesman licenses (three-year cycle)Continuing education requirements for plumbing license renewal or reinstatementRenewal fees for tradesman and plumbing licensesReinstatement fees and the 30-day grace period triggerMaximum reinstatement window (24 months) and new application requirements after expirationRole of fee receipt date in determining renewal versus reinstatement eligibilityBoard's authority to deny renewal for disciplinary or non-payment reasons
Definitions
1 Q · 1%
IPC plumbing system component definitions (fixtures, appliances, appurtenances)Drainage system terminology (building drain, building sewer, soil pipe, waste pipe, stack)Backflow and cross-connection terminology (backflow, backsiphonage, backpressure, cross connection, air gap, air break)Vent system terminology (vent stack, stack vent, branch vent, circuit vent, relief vent, individual vent)Water supply system terminology (potable water, nonpotable water, water service pipe, water distribution pipe, riser)Virginia-defined tradesman classifications (master, journeyman, plumber, residential plumber tradesman)Virginia definition of plumbing work and scope of regulated activitiesCode interpretation rules for undefined or cross-referenced terms
Qualification for Licensure
1 Q · 1%
Experience and education requirements for master plumber licensure (education/experience equivalency tables)Qualifications pathway from journeyman or residential plumber tradesman license to master licenseApplication procedures and documentation requirements for tradesman licensureVerification of experience and education (acceptable references and credentials)Examination requirements and exemptions for tradesman licensureOut-of-jurisdiction license reciprocity and substantial equivalency standardsMinimum age and character disclosure requirements (felony/misdemeanor reporting)License fees, application timelines, and nonrefundable fee rules
Revocation of Licensure
1 Q · 1%
Grounds for denial, suspension, or revocation of a contractor or tradesman licenseBoard authority to impose remedial education, monetary penalties, and license suspension as disciplinary alternativesProhibited acts constituting grounds for disciplinary action (fraud, misrepresentation, negligence, misconduct, abandonment)Effect of revocation on eligibility for re-licensure under any name or circumstanceSubstantial identity of interest as basis for denying or revoking a licenseNotification requirements after revocation (Board notice to Director, clerks, and building officials)Reporting obligations of regulants following out-of-state license suspension, revocation, or criminal convictionFiling and investigation of complaints and conduct of disciplinary proceedings under the Administrative Process Act
Drainage Waste and Vents
24 Q · 30%
Drainage fixture unit (DFU) values and fixture load calculationsSizing of horizontal drainage piping, building drains, and building sewersSlope requirements for horizontal drainage pipingVent pipe sizing and developed length limitsTypes of venting methods (individual, common, wet, circuit, combination waste and vent, air admittance valves)Cleanout requirements, placement, spacing, and accessPipe materials and approved joint methods for drainage and vent systemsIndirect waste requirements and air gap/air break distinctions
Water Supply Systems
10 Q · 12%
Backflow prevention devices and assemblies (air gaps, vacuum breakers, reduced pressure principle assemblies, double check assemblies)Cross connection control and potable water protectionWater service pipe sizing, materials, and separation requirementsPipe and fitting materials, joint methods, and connection standards for water distributionWater piping system sizing methods (fixture units, pressure calculations, segmented loss method)Hot water supply system requirements, temperature limits, and recirculation systemsWater pressure regulation, booster systems, and water hammer controlWater heater safety devices (T&P relief valves, discharge piping, pans, vacuum relief)
Backflow Prevention
10 Q · 12%
Types of backflow and cross-connection hazard levels (high hazard vs. low hazard, backpressure vs. backsiphonage)Backflow preventer device and assembly selection per Table 608.1 (air gap, reduced pressure principle, double check, vacuum breaker, dual check)Air gap requirements and minimum distances per Table 608.16.1Reduced pressure principle backflow prevention assembly installation requirements (ASSE 1013, relief port discharge)Pressure vacuum breaker and atmospheric vacuum breaker installation requirements (critical level heights, ASSE 1020, ASSE 1001)Specific application requirements for backflow protection (boilers, sprinkler systems, irrigation, chemical dispensers, carbonated beverage dispensers, hose connections)Backflow protection requirements where potable water connects to nonpotable water systems (reclaimed water, rainwater, on-site reuse)Identification and marking of nonpotable water piping systems (color coding, signage, labeling intervals)
Storm Drainage Systems
10 Q · 12%
Rainfall intensity determination using 100-year hourly rainfall rates and geographic dataStorm drain pipe sizing using flow rate tables and slope calculationsRoof drain sizing, flow rates, and head of water calculationsSecondary (emergency) roof drains and scupper requirementsApproved materials and standards for storm drain conductors, building storm sewers, and subsoil drain pipeSubsoil drains and sump pumping systemsProhibited connections and disposal requirements for storm waterSiphonic and controlled flow roof drain systems
Plumbing Fixtures
7 Q · 9%
Minimum fixture counts by occupancy type (Table 403.1)Fixture installation requirements (spacing, clearance, and setting)Fixture material standards and prohibited fixturesFaucets and fixture fittings standards (temperature control, backflow protection, flow rates)Accessible plumbing fixture requirements (ICC A117.1 dimensions and clearances)Flushing devices for water closets and urinalsWater heater safety devices (T&P relief valves, discharge piping, pans)Specific fixture requirements by type (bathtubs, showers, water closets, urinals, sinks, bidets, drinking fountains)
General Regulations
5 Q · 6%
Permit requirements, application procedures, and exemptionsInspections and testing of plumbing systems (underground, rough-in, and final)Code official authority, duties, and enforcement powersStop work orders, violations, and penaltiesProhibited locations and protection of piping from damage, freezing, and corrosionTrenching, bedding, and backfill requirements for buried pipingPiping support intervals and anchorage requirementsNonflammable medical gas and nonmedical oxygen system installation standards
Interceptors and Traps
4 Q · 5%
Fixture trap requirements and prohibited trap typesTrap seal depth requirements and protection methodsGrease interceptor installation, sizing, and applicabilityOil separator design and required locationsSand, solids, and specialty interceptorsIndirect waste piping and air gap/air break requirementsVenting, access, and maintenance of interceptors and separatorsNeutralizing devices for corrosive and special wastes
Key Distinctions
Flow pressurevsStatic pressure
Flow pressure is the pressure in the water supply pipe near the faucet or outlet while it is wide open and flowing, whereas static pressure is the non-flowing supply pressure (e.g., at the meter) from which elevation, meter and residual losses are subtracted.
IPC 2021 Page 2-4Cross connection between a private water supply and a potable public supplyvsOther cross connections
A private-to-public potable cross connection is prohibited under no condition (no backflow preventer makes it acceptable), while general cross connections may be permitted when protected with approved backflow prevention.
IPC 2021 Section 608.7.1Metallic piping contact with steel framing, concrete, cinder walls/floors or masonryvsMetallic piping contact with corrosive soil
Cast iron, ductile iron and galvanized steel are excepted from the prohibition on direct contact with steel framing, concrete, cinder walls/floors and masonry, but the corrosive-soil prohibition applies to all metallic piping with no exception.
IPC 2021 Section 305.1Air test of a cast-iron DWV systemvsWater supply system test
The DWV air test uses a uniform gauge pressure of 5 psi (or enough to balance a 10-inch mercury column) held not less than 15 minutes and may not be used on plastic piping, while the water supply system is tested at not less than the system working pressure held not less than 15 minutes.
IPC 2021 Section 312.3PVC hanger spacing — horizontalvsPVC hanger spacing — vertical
Table 308.5 permits a maximum of 4 feet between horizontal PVC hangers but 10 feet for vertical support spacing.
IPC 2021 Table 308.5Individual vent minimum size (half the fixture drain)vsVent upsizing for developed length over 40 feet
An individual vent is sized at one-half the fixture drain size but never smaller than 1-1/4 inch (e.g., 1-1/2 inch for a 3-inch WC drain at 18 ft), while any vent exceeding 40 feet developed length must be increased one nominal pipe size for its entire length.
IPC 2021 Section 906.2Tradesman license renewal feevsTradesman license reinstatement fee
The renewal fee is $160.00, but if renewal requirements are not completed within 30 days of expiration a $210.00 reinstatement fee (which includes the renewal fee) applies; all fees are nonrefundable and not prorated.
Virginia Board for Contractors Regulations (18 VAC 50-30), Page 22 (18 VAC 50-30-120 G)30-day renewal grace periodvs24-month reinstatement window
Renewal requirements completed within 30 days of expiration avoid a reinstatement fee, while a license may still be reinstated for up to 24 months after expiration by paying the reinstatement fee and meeting applicable renewal requirements.
Virginia Board for Contractors Regulations (18 VAC 50-30), Page 23Contractor is solely responsiblevsContractor shares responsibility equally
Under § 54.1-1115.01 a contractor that employs or contracts with a person lacking the required Board credential is solely responsible for any monetary penalty or sanction, not equally responsible with that person.
Virginia Board for Contractors Regulations (18 VAC 50-30), Code of Virginia § 54.1-1115.01Class A contractor — single contract/project thresholdvsClass A contractor — 12-month threshold
Class A applies when the total value in a single contract or project is $150,000 or more, or when the total value of all such work within any 12-month period is $1 million or more.
Virginia Board for Contractors Regulations (18 VAC 50-30), Code of Virginia § 54.1-1100Annual testing of backflow prevention assembliesvsAnnual inspection of backflow assemblies and air gaps
Testable assemblies (reduced pressure principle, double check, pressure vacuum breaker, detector fire protection types, spill-resistant vacuum breakers, hose connection backflow preventers) must be tested at installation, immediately after repairs or relocation, and at least annually; annual inspections determine whether assemblies are operable and air gaps exist.
IPC 2021 Page 3-545° offset travel constant (1.414)vs22½° offset travel constant (2.613)
For the same set, travel = set × 1.414 with 45° fittings but travel = set × 2.613 with 22½° fittings, so the shallower fittings give a much longer travel.
Key Terms
Flow pressure IPC 2021 Page 2-4
The pressure in the water supply pipe near the faucet or water outlet while that faucet or outlet is wide open and flowing (IPC Section 202).
Developed length IPC 2021 Page 2-3
The length of a pipeline measured along the centerline of the pipe and fittings, following the actual pipe path rather than the straight-line distance (IPC Section 202).
Backsiphonage IPC 2021 Section 202 Definitions
The backflow of potentially contaminated water into the potable water system caused by the pressure in the potable system falling below atmospheric pressure of the fixtures, pools, tanks or vats connected to the potable distribution piping.
Cross connection IPC 2021 Section 202 Definitions
Any physical connection or arrangement between two otherwise separate piping systems, one containing potable water and the other water of unknown or questionable safety or steam, gas or chemical, whereby flow from one system to the other is possible.
Branch interval IPC 2021 Definitions (Branch Interval)
A vertical measurement of distance of 8 feet or more in developed length between the connections of horizontal branches to a drainage stack.
Building drain IPC 2021 Definitions (Building Drain)
The lowest piping that collects discharge from all other drainage piping inside the house and extends 30 inches in developed length beyond the exterior walls, conveying drainage to the building sewer.
Area drain IPC 2021 Chapter 11
A drain in a paved court or yard that collects surface storm water.
Lead-free solder/flux IPC 2021 Section 605.12.3
Solder and flux with a chemical composition equal to or less than 0.2-percent lead, required for joining water supply piping (IPC 605.12.3).
Water-hammer arrestor IPC 2021 Section 604.9
A device conforming to ASSE 1010 that is required to be installed where quick-closing valves are utilized, per the manufacturer's instructions (IPC 604.9).
Prohibited joints and connections (water supply) IPC 2021 Section 605.9
Per IPC 605.9 these include cement or concrete joints, joints made with fittings not approved for the installation, solvent-cement joints between different types of plastic pipe, and saddle-type fittings.
Cleanout equivalent IPC 2021 Section 708.1.6; 708.1.5 Exception 1
A fixture trap or a fixture with an integral trap that is removable without altering concealed piping is acceptable as a cleanout equivalent (IPC 708.1.6).
Segmented loss method IPC 2021 Page E-4 (Section E103.3, Step 6)
A water pipe sizing method in which fittings and valves are approximated by adding 50 percent of the developed length to get equivalent length, and equipment such as backflow preventers, check valves, softeners, tankless heaters, filters and strainers is credited with 8 to 30 psi of loss.
Auxiliary drain pan (under cooling coils) IPC 2021 Section 314.2.3
A corrosion-resistant pan not less than 1½ inches deep and not less than 3 inches larger than the unit or coil in width and length (Section 314.2.3, Item 1).
Regulant conviction reporting Virginia Board for Contractors Regulations (18 VAC 50-30), 18 VAC 50-30-190(11)
A regulant convicted of any felony, or a misdemeanor involving lying, cheating, stealing, sexual offense, non-marijuana drug distribution, physical injury, or relating to the practice of the profession, must inform the board in writing within 30 days, regardless of jurisdiction (18 VAC 50-30-190(10) and (11)).
Tradesman license term and continuing education Virginia Board for Contractors Regulations (18 VAC 50-30), Page 22 (18 VAC 50-30-120 A)
Licenses for electricians, gas fitters, LP gas fitters, natural gas fitter providers, HVAC tradesmen and plumbers expire three years from the last day of the month of issuance; as a condition of renewal/reinstatement, holders of the plumbing, electrical and HVAC trade designations must complete three hours of board-approved continuing education on applicable building code changes for each designation, while gas fitter, liquefied petroleum gas fitter and natural gas fitter provider licensees need only one hour.
Aiding or abetting an unlicensed contractor Virginia Board for Contractors Regulations (18 VAC 50-30), 18 VAC 50-30-190(8)
Allowing one's license or certification to be used by an unlicensed or uncertified individual, a prohibited act subject to disciplinary action (18 VAC 50-30-190(8)).
Formulas to Know
Water heater recovery capacity (gallons per hour; tankless GPM)
GPH = (input BTU/hr × efficiency) ÷ (8.33 lb/gal × temperature rise °F); for a tankless heater, GPM = GPH ÷ 60. Ex: (199,000 × 0.84) ÷ (8.33 × 70) = 286.7 GPH ÷ 60 = 4.78 GPM; (40,000 × 0.75) ÷ (8.33 × 70) = 51.4 GPH.BTU required to heat water, and electric heating time
BTU = gallons × 8.33 lb/gal × temperature rise °F (ex: 30 × 8.33 × 95 = 23,740 BTU). Electric output BTU/hr = watts × 3.413; time (min) = (BTU required ÷ BTU/hr) × 60.Pressure available to overcome pipe friction
Available psi = supply pressure − (height in ft × 0.433 psi/ft) − meter loss − other device/fitting losses − minimum required residual. Where a PRV is installed, start with the PRV outlet (downstream) setting instead of the street pressure. Ex: 60 − 15.2 − 7 − 8 = 29.8 psi; 45 − 15.2 − 7 − 8 = 14.8 psi.Maximum allowable friction loss rate for pipe sizing charts
psi per 100 ft = (available pressure ÷ total equivalent length, including fittings) × 100. Ex: (22 ÷ 250) × 100 = 8.8 psi per 100 ft.Total piping friction loss using equivalent length
Equivalent length = developed length × (1 + fitting allowance); friction loss = equivalent length × (psi per 100 ft ÷ 100). Ex: 120 × 1.40 = 168 ft; 168 × 4.2/100 = 7.06 psi. Code rule of thumb adds 50% of developed length (225 × 1.5 = 338 ft).Offset travel from set
45° offset: travel = set × 1.414 (22 × 1.414 = 31.1 in). 22½° offset: travel = set × 2.613 (20 × 2.613 = 52.26 in ≈ 52-1/4 in).Pipe cut length from center-to-center dimension
Threaded: cut = center-to-center − (takeoff × 2 fittings) + (thread engagement × 2 ends), ex: 36 − (2×2) + (2×½) = 33.00 in. Socket/solder with ½ in per fitting end: cut = 18 − (2 × ½) = 17.00 in.Fall on sloped drains and invert elevations
Fall (in) = run (ft) × slope (in/ft), ex: 44 × 1/8 = 5.5 in; 56 × 1/4 = 14 in = 1.167 ft. Upstream invert = downstream invert + fall (94.00 + 1.167 = 95.17 ft); downstream invert = upstream invert − fall of each segment (100.00 − 0.667 − 2.00 = 97.33 ft).Water volume in gallons (tanks, pans, pipes)
Cubic feet × 7.48 = gallons. Rectangular: L×W×D (7×5×2.5 = 87.5 cf = 654.5 gal; fill time = gal ÷ GPM). Cylinder: π r² h (π×2²×3 = 37.7 cf = 282 gal). Half-cylinder: (π r² L) ÷ 2. Cone: (π r² h) ÷ 3 (12.566 cf = 94.0 gal). Pipe: use inside radius in feet, π r² × length (3-in ID, 250 ft = 12.27 cf = 91.9 gal).Oil separator capacity at garages and service stations
Capacity = 6 cubic feet for the first 100 sq ft of floor area + 1 cubic foot for each additional 100 sq ft. Ex: 500 sq ft = 6 + (4 × 1) = 10 cubic feet.