Exam Cheat Sheet · Quick Reference

Georgia Master Plumber Class I (Restricted) Exam

Georgia  ·  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
120
Passing score
70%
Exam time
420 min
Administered by
PSI Services Contractor
Format
Closed-book

Georgia State Portion 120 questions

Comply with General Laws 5 Q · 4%
Georgia Construction Industry Licensing Board (complaint procedures, function of, renewal, etc.)Location law for underground utilitiesAmericans with Disabilities Act (ADA)American National Standards Institute (ANSI) Handicap AccessibilityState water conservation lawADA employment obligations (reasonable accommodation, undue hardship, essential functions, medical examinations)ADA enforcement, remedies, and EEOC complaint proceduresPenalties and criminal offense notification requirements for licensed contractorsLicense display and business registration number requirementsUnlicensed practice prohibitions, cease and desist orders, and civil penalties
Comply with Regulations 15 Q · 12%
Georgia State Plumbing Code and Standard Building Code Congress (SBCCI) Plumbing CodeStandard Building Code Congress (SBCCI) Gas CodeCode of Federal Regulations, Title 29, Part 1926 (OSHA)Obtain necessary permits and inspections (plumbing, boiler, etc.)State Trenching LawGeorgia State Boiler CodeHealth DepartmentManufacturer's recommendationsCode official authority, permit applications, inspections, and enforcement procedures under IPC and IFGCGeorgia state amendments to IPC and IFGC, including high-efficiency fixture requirements and boiler/water heater thresholds
Work Planning/Organizing 8 Q · 7%
Compile bill of materials from drawing and specifications (job takeoff)Interpret equipment name plate data: pump, water heater, backflow preventer, lift stations, etc.Draw waste and water diagrams (isometrics)Interpret bar chart scheduleDetermine precedence of various codes, laws, manufacturer's instructions, regulations, etc.Scheduling methods: calendar, bar chart, and critical path method (CPM)Quantity take-off estimating process and materials cost determination
Perform Pipe Cutting and Joining Activities 4 Q · 3%
Cut cast-iron pipe (using snap-type chain cutter, hammer and chisel, metal saw, demolition saw, hydraulic cutters, etc.)Cut concrete pipe (using saws, hammer and chisel, etc.)Cut and ream copper tubing and pipe (using metal saws, tubing cutter, etc.)Cut and ream plastic pipe (using saws, tubing (scissor) cutter, etc.)Cut and ream steel pipe (using hand pipe cutter, metal saw, power pipe cutter, etc.)Join cast-iron soil pipe (using lead and oakum, rubber-type seal, no-hub connectors, etc.)Use transition fittings (clay pipe to cast-iron pipe, cast iron to plastic, etc.)Join copper or brass pipe (tubing) to fittings (sweat method, compression, flare, T-drill method, etc.)Join PVC, CPVC plastic pipe using solvent method, fusion method, threaded, grooved, etc.Cut and join ductile iron pipeJoin steel pipe (threaded, welded, grooved, flanged, etc.)Cut and join vent and flue pipe (Class B and C) +8 more
Perform Plumbing Systems Installation Activities 16 Q · 13%
Interpret plans and install according to specificationsSize and install water supplySize and install drainage systemsSize and install gas pipesAssemble plumbing fittings and fixtures (interpret manufacturer's instructions)Locate/mark holes for plumbing in walls, ceilings or floorsInstall pipe through concrete walls, ceilings, or floorsInstall pipe through wood floorsInstall pipe through metal walls, ceilings or floorsInstall pipe to meet fire code regulationsSecure horizontal and vertical lines of pipe to masonry and concrete, metal, etc., surfacesSecure horizontal and vertical lines of pipe to wood surface +33 more
Perform System Testing Activities 5 Q · 4%
Pressure test water distribution system (air, water, hydrostatic, etc.)Test sanitary and drainage systems (water, smoke, air, peppermint, etc.)Pressure test gas lines (air)Certify backflow testSterilize potable water systems and obtain certificationTest gauge requirements and pressure increments for system testingWater test vs. air test procedures and applicability by pipe materialRequired test durations and minimum pressure headsInspection sequencing and open trench requirements before concealmentGravity sewer test and forced sewer test procedures
Perform Maintenance and Repair Activities 11 Q · 9%
Locate leaks in gas supply lines (using soapy water, gas detector)Service gas appliances (clean and adjust gas burners, check valves and venting, etc.)Service electric appliances (replace electric water heater element, check controls, relief valves, etc.)Locate, identify and remove obstructions in drain lines and water closetsClean backwater valvesRepair leaking water faucets or valvesRepair tank type and flush valve water closetsLocate leak in drainage/vent systems (peppermint test, Smoke test)Free jammed garbage disposalTest/adjust pressure reducing valvesTest/replace thermocouple and/or pilot lightService backflow preventer +7 more
Safety-related Issues 11 Q · 9%
Identify and control for hot water heater and pressure vessels (vent system – slope, classification, sizing, routing and termination; testing, relief valves – sizing, pressure rating, routing and termination, etc.)Identify and control for gas piping: testing and supportIdentify and control for backflow preventionIdentify and control for personal safety: poisonous gases, trenching, faulty equipment, etc.Personal protective equipment (PPE) selection, use, and employer requirementsFall protection systems: guardrail, safety net, and personal fall arrest systemsLadders and stairways: safe use, inspection, and OSHA requirementsFire protection and prevention: extinguisher types, flammable liquid storage, and fire prevention programsHand and power tool safety: guarding, switches, and proper useWelding and cutting safety: compressed gas cylinder handling and storageConfined space entry: permit-required spaces, atmospheric testing, and rescue proceduresExcavating near underground utilities: tolerance zone, hand digging, and damage reporting (Georgia 811)
Calculate the following during installation and service: offset, volume, area, pressure, depth, circumference, radius, weight, etc. 5 Q · 4%
Pipe offset calculations using 45° constants (diagonal, rise, run relationships)Volume calculations for cylinders, rectangular solids, and spheresWater pressure and head calculations (psi to feet of head conversion)Grade, drop, and percent grade calculations for drainage pipingDecimal and fractional inch conversions and metric unit conversionsPipe capacity and gallons-per-foot calculations using pipe dataArea calculations for circles, rectangles, and irregular shapes
Comply with Business Laws 15 Q · 12%
Workers' compensationUnemployment insuranceEmployer's tax guide (circular E)State sales and use taxBusiness licenseCompletion of I-9 formLien rightsFair Labor Standards Act minimum wage, overtime, and recordkeeping requirementsEmployee vs. independent contractor classification under IRS guidelinesGeorgia Prompt Pay Act payment timing and withholding rightsBusiness entity structure selection and registration requirementsNew hire reporting requirements under Georgia law +1 more
Comply with Administrative Requirements 15 Q · 12%
Bonding and liquidated damagesInsurance: liability, property damage, auto, etc.Financing and cash flowBookkeeping and accountingJob cost estimating and bidding proceduresContracts and purchase ordersScheduling and project managementAccident or incident reportsPerformance, payment and bid bonds; surety prequalification and underwritingProgress payments, retainage and change orders under construction contractsCash flow projections, working capital and job cost recordsOverhead allocation, markup and profit in bid preparation
Plumbing System Design 10 Q · 8%
Select sump reservoirSelect water heaters (size and capacity)Select boilers (size and capacity)Select specialty fixtures: hospital, medical, restaurant, prison, etc.Select industrial piping and fixturesSelect specialty piping: medical, gas, air, vacuum, etc.Select sewage ejection systemsSelect valves: backflow, T and P, pressure relief, check, vacuum relief, backwater, pressure-reducing, etc., according to manufacturer's specificationsSelect specialty traps and interceptors (grease, sand, oil, etc.)Select shower and safety pansSelect fixtures according to ADA, ANSI regulationsSelect specialty waste systems (continuous, indirect, and safe waste systems, open site drains, trailer site waste systems, etc.) +4 more

Key Distinctions

AddendavsModifications

Addenda are contract changes made before the contract award, while modifications are changes made after the contract is signed and executed.

NASCLA Contractors Guide, Chapter 7 - Contract Management
ArbitrationvsMediation

In arbitration a third-party arbitrator acts as a judge and renders a decision legally binding on all parties, while in mediation a neutral third party only facilitates dialogue and the parties themselves set the terms of any agreement.

NASCLA Contractors Guide, Contract Management chapter — Alternative Dispute Resolution section
All-risk builders' risk insurancevsNamed peril builders' risk insurance

All-risk covers direct loss by any peril not specifically excluded by the policy, while named peril is narrower and covers only the perils it specifies, such as fire and lightning.

NASCLA Contractors Guide, Managing Risk chapter — Insurance section
Project overheadvsCompany overhead

Project overhead is indirect cost necessary to complete a specific project (bonds, temporary storage/office, security, utilities, dumpsters, portable toilets, small tools and pickup trucks), while company overhead is the general cost of doing business not linked to a project (office rent, legal fees, accounting fees).

NASCLA GA CILB 5th Ed., Chapter 7 - Bidding and Estimating (Add Project Overhead / Add Company Overhead)
Free floatvsTotal float

Free float is the time an activity can be delayed without impacting the early start of the next activity, while total float is the leeway in starting or completing an activity without delaying the project completion date.

NASCLA Contractors Guide, Georgia CILB (5th ed.), Chapter 9 — Float Time
Danger signsvsCaution signs

Per OSHA 1926.200, danger signs are used only where an immediate hazard exists (red upper panel, black border outline, white lower panel), while caution signs warn against potential hazards or unsafe practices.

OSHA 1926 CFR 29, §1926.200(b)(1)
Type K copper tubingvsType DWV copper tubing

Type K has the thickest wall of the four types and is recommended for underground and interior water service, while Type DWV is the lightest weight type, made for nonpressure drainage, waste and vent service.

Mathematics for Plumbers and Pipefitters (8th ed.), Pages 42-43 (Unit 9 - Copper Tubing)
PVC pipevsCPVC pipe

Standard PVC loses strength as temperature rises (Schedule 40 retains only 62% of rated strength at 100°F), while CPVC is for hot water at 120°F and higher with an upper working temperature of 215°F.

Mathematics for Plumbers and Pipefitters (8th ed.), Pages 46-47 (Unit 11 - Plastic Pipe)
Social security taxvsMedicare tax

Social security tax applies only up to an annual wage base limit, while Medicare tax has no wage base limit and applies to all covered wages; both are paid in equal shares by employer and employee.

Circular E (Pub. 15), Tax rates and the social security wage base limit
ConductorvsLeader

A conductor is a pipe inside the building conveying storm water from the roof to a storm or combined building drain, while a leader is the exterior drainage pipe conveying storm water from roof or gutter drains to an approved means of disposal.

IPC 2024 Section 202 (Conductor)
Air test of DWV piping (IPC 312.3)vsAir test of water supply piping (IPC 312.6)

A drainage and vent system is air tested at a uniform 5 psi (or enough to balance a 10-inch mercury column) for not less than 15 minutes, while a water distribution system may be air tested at not less than 50 psi for not less than 15 minutes; neither air option is permitted on plastic piping.

IPC 2024 Section 312.3
Bank letter of creditvsPerformance bond

A letter of credit is a cash guarantee a bank can convert to payment to the owner, customarily 5 to 10 percent of the contract amount and not a guarantee of performance, while a performance bond is usually written for 100 percent of the contract amount (surety premiums typically run one-half to two percent).

NASCLA GA CILB 5th Ed., Chapter 4 - Managing Risk (Bank Letter of Credit)
Billings in excess of cumulative earningsvsBillings less than cumulative earnings

Under the percentage of completion method, billings that exceed cumulative earnings are reported as a current liability, while billings below cumulative earnings are reported as a current asset.

NASCLA GA CILB 5th Ed., Chapter 14 - Financial Management (Percentage of Completion Method)

Key Terms

Competent person (29 CFR 1926.32(f)) OSHA 1926 CFR 29, Page 31
One capable of identifying existing and predictable hazards in the surroundings or working conditions that are unsanitary, hazardous or dangerous, and who has authorization to take prompt corrective measures to eliminate them — no specific degree, years of experience or certificate is required.
Tolerance zone (O.C.G.A. § 25-9-3) NASCLA Contractors Guide, Georgia CILB (5th ed.), Appendix G, O.C.G.A. § 25-9-3
The width of the utility facility or sewer lateral plus 24 inches on either side of the outside edge of the facility, measured on a horizontal plane, within which reasonable care such as hand digging or vacuum excavation is required.
Backpressure, low head (IPC Section 202) IPC 2024 Section 202 (definition of Backpressure, Low Head)
A pressure less than or equal to 4.33 psi (29.88 kPa), the pressure exerted by a 10-foot column of water; devices rated only for low head backpressure may not be used where anticipated backpressure exceeds this value.
Conductor (IPC Section 202) IPC 2024 Section 202 (Conductor)
A pipe inside the building that conveys storm water from the roof to a storm or combined building drain.
Invert Mathematics for Plumbers and Pipefitters (8th ed.), Page 129 (Unit 34)
The inside bottom of the pipe, which is the reference point to which elevations of house sewers and house drains are measured (most other pipe is measured to centerline).
Prima-facie evidence of unlicensed utility contracting (O.C.G.A. § 43-14-12.2) NASCLA Contractors Guide, Georgia CILB (5th ed.), Appendix E — O.C.G.A. § 43-14-12.2
Advertising by an unlicensed person in a manner leading the general public to believe he is a licensed utility contractor is itself prima-facie evidence of a chapter violation, and an investigator need not observe work in progress or completed work.
Workweek (FLSA) NASCLA Contractors Guide, Employee Management chapter — Fair Labor Standards Act (FLSA) section
A period of 168 hours during seven consecutive 24-hour periods.
Collaborative law NASCLA Contractors Guide, Contract Management chapter — Alternative Dispute Resolution section
A facilitative ADR process in which all parties agree at the onset to find a mutually beneficial solution and negotiate through their advocates, usually lawyers, with no neutral mediator or arbitrator involved.
Equipment floater policy NASCLA GA CILB 5th Ed., Chapter 4 - Managing Risk (Equipment Floater Policy)
A type of inland marine insurance covering direct physical loss to mobile equipment stored on premises, in transit, or at temporary locations and jobsites, with an endorsement available for rented or leased equipment; normal wear and tear is not covered.
Temporary partial disability (O.C.G.A. § 34-9-262) NASCLA Georgia, Appendix I: Georgia Workers' Compensation Law, O.C.G.A. § 34-9-262
A Georgia workers' compensation benefit paying two-thirds of the difference between the pre-injury average weekly wage and what the employee is able to earn after the injury, subject to the statutory weekly maximum.
Equal lien ranking (O.C.G.A. § 44-14-361.1(b)) NASCLA Georgia, Appendix J: Georgia Contractor and Material Supplier Lien Law, O.C.G.A. § 44-14-361.1(b)
Liens rank by date filed, but all liens for repairs, building, or furnishing materials or services on the same property are treated as of the same date relative to each other when declared and filed for record within 90 days after the work is done.
Sales and use tax escrow withholding (Georgia) NASCLA Georgia, Chapter 15: Tax Basics — Sales and Use Tax
On a subcontract of $250,000 or more, a resident subcontractor may post a surety bond (ST-C Forms 214-2 and 214-3) or instead request the prime contractor to withhold 2 to 4 percent of all payments in escrow, released on completion via Form ST-C 214-9-RR.
ASSE 1044 IPC 2024 Section 1002.4.1.3
The standard to which a wastewater-supplied trap primer device must conform under IPC 1002.4.1.3, with its discharge pipe connected to the trap above the trap seal on the inlet side.
ASTM F656 IPC 2024 Chapter 15 (ASTM F656), referenced in Section 705.10.2
The specification for primers used in solvent cement joints of PVC plastic pipe and fittings (ASTM D2564 is the PVC solvent cement, D2235 the ABS cement, D2855 the two-step joining practice).
Form SS-8 Circular E (Pub. 15), Section 2: Who Are Employees? — IRS help
The IRS form filed to obtain an official determination of whether a worker is an employee or an independent contractor.
Form 1099-NEC NASCLA Contractors Guide, Chapter 14 – Information Returns 1099-MISC
The IRS information return used, beginning with tax year 2020, to report payments of $600 or more made to independent contractors (previously reported on Form 1099-MISC).
Social Security Number Verification Service (SSNVS) Circular E (Pub. 15), Hiring New Employees — Eligibility for employment
A service that verifies only that an employee's name matches the social security number on file; it does not establish work authorization, so Form I-9 must still be completed for each new hire.

Formulas to Know

Fall (drop) of a horizontal drain and resulting invert elevationDrop = grade × run (e.g., 1/4 in/ft × 18 ft = 4-1/2 in; 1/8 in/ft × 44 ft = 5-1/2 in). Downstream invert = upstream invert − total fall; moving upstream, elevation increases (1/8 in/ft ≈ 0.01 ft per foot, so 0.01 × 25 ft = 0.25 ft added).
Static pressure loss from vertical risePressure change ≈ 0.433 psi per vertical foot of water; 10 ft × 0.433 = 4.33 psi.
Electric water heater kW to Btu/hBtu/h = kW × 3,412 (4.5 kW × 3,412 = 15,354 Btu/h; 15 kW × 3,412 = 51,180 Btu).
Gas water heater recovery time and gallons per hourHeat required = gallons × 8.33 lb/gal × temperature rise (°F). Usable output = input Btu/h × efficiency. Recovery time (hr) = heat required ÷ usable output (× 60 for minutes); GPH = usable output ÷ (8.33 × rise).
Maximum allowable friction loss rate for water pipe sizingAllowable friction rate = (available pressure ÷ total equivalent length including fittings) × 100; e.g., (22 psi ÷ 250 ft) × 100 = 8.8 psi per 100 ft.
Total gas load in cubic feet per hourSum the maximum input of all appliances served (assume simultaneous full capacity), then divide by the heating value: 240,000 Btu/h ÷ 1,000 Btu/cu ft = 240 cfh. For CSST runs with extra bends, add equivalent length L = 1.3n, where n is the number of additional bends/fittings beyond the table's standard four bends and two fittings.
Bid price when overhead is a percentage of revenueBid price = direct costs ÷ (1 − total overhead %); e.g., 8% + 12% = 20%, so $180,000 ÷ 0.80 = $225,000 (adding 20% to cost understates recovery). Material cost = unit price × quantity after adding waste contingency (480 ft × 1.05 = 504 ft × $6.40 = $3,225.60). Labor cost per task = required labor hours × labor rate.
Percentage of completion earnings and billing position% complete = costs incurred ÷ total estimated costs; cumulative earnings = % complete × contract amount; cumulative earnings − amount billed gives the difference (billings in excess = current liability; billings under = current asset).
Offset and travel constants45° offset: run = offset (rise = offset) and diagonal (travel) = offset × 1.414 (0.707 reverses it). 60° offset: diagonal = offset × 1.1547 (cosecant 60°), run = offset × 0.5774 (cotangent 60°). Rolling offset: true offset = √(offset² + rise²), then multiply by the fitting-angle constant.
End-to-end cut length from center-to-centerThreaded pipe: e-e = c-c − [2(A) − 2(B)], where A = center-to-face and B = thread-in (48 in − [3 in − 1 in] = 46 in). Copper/PVC: fitting allowance = center-to-face minus depth of solder cup/socket, and e-e = c-c − sum of the two fitting allowances (10 in − 7/8 in = 9-1/8 in).
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