Idaho Plumbing Contractor Exam

Key Concepts

Chapter 2 of the 2017 Idaho State Plumbing Code (based on the 2015 UPC) establishes precise definitions that govern how all other code sections are interpreted. Knowing exact distinctions between similar terms is critical.

Drainage System Terms - Building Drain: Lowest piping inside the building that receives discharge from soil, waste, and other drainage pipes; extends to 2 feet (610 mm) outside the building wall. - Building Sewer: Begins at the end of the building drain (2 ft outside the wall) and carries discharge to the public sewer or disposal point. - Soil Pipe: Carries waste from water closets or fixtures with fecal matter. - Waste Pipe: Carries liquid waste that does not contain fecal matter. -…

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Permits & Inspections (Sections 502–503)

• A permit is required before installing, removing, or replacing any water heater — no exceptions (§502.1).
• Two inspections are required:
• Vent/chimney inspection (§503.1): After installation but before covering or concealing.
• Final inspection (§503.2): After all permitted work is complete. Nothing shall be covered until inspected and approved.

Water Heater Location Requirements (§504.1)

• Bedrooms and bathrooms: Fuel-burning water heaters are only allowed if:
• Installed in a dedicated closet with a listed, gasketed, self-closing door assembly (with threshold and bottom door seal), combustion air from outdoors only (§506.4); OR
• The water heater is direct-vent type.
• Garages: Must be elevated so the ignition source…

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Cross-Connection Control & Backflow Prevention (Section 603.0) Backflow prevention device selection depends on the degree of hazard (pollutant vs. contaminant) and type of backflow (backsiphonage vs. backpressure). Know these assemblies:

• Air Gap (AG): Physical separation — highest protection; required for direct connections to sewage/high hazard. Minimum 2× pipe diameter or 1" above flood rim, whichever is greater.
• Atmospheric Vacuum Breaker (AVB): Protects against backsiphonage only; cannot be installed under continuous pressure or downstream of shutoff valves; must be installed at least 6" above highest outlet.
• Pressure Vacuum Breaker (PVB): Can be under continuous pressure; still backsiphonage only; install minimum 12" above highest outlet.
• Spill-Resistant Vacuum Breaker (SVB): Similar to PVB with reduced spillage;…

Exam Weight: 2 questions, 2% — know the rules cold; don't overthink edge cases.

Key Concepts

Approved Pipe Materials & Permitted Locations (Table 701.2) Know which materials are allowed where: - ABS, PVC (Sch. 40), Cast-Iron, Copper (Type DWV), Stainless Steel 316L: Approved underground, aboveground, AND building sewer - Galvanized steel/wrought iron: Aboveground ONLY — must be kept ≥6 inches above grade - Stainless Steel 304: Aboveground ONLY — must be kept ≥6 inches above grade - Vitrified clay: Building sewer ONLY — no aboveground use, must be ≥12 inches belowground, cannot be pressurized - Polyethylene: Building sewer ONLY

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Air Gap vs. Air Break (Section 801.2) - All indirect waste piping must discharge through an air gap or air break - Minimum air gap = 1 inch (25.4 mm) vertical distance from lowest point of indirect waste pipe to the flood-level rim of the receptor - Air gap is required (not just air break) for: food-handling fixtures (801.3.3), sterilizers (801.6), walk-in coolers under vacuum (801.3.2), and potable water pressure connections (801.5)

Food and Beverage Equipment — Indirect Waste Required (Section 801.3) Equipment requiring indirect waste connections includes: refrigerators, refrigeration coils, freezers, walk-in coolers, iceboxes, ice-making machines, steam tables, egg boilers, coffee urns/brewers, hot-and-cold drink dispensers.

Key Concepts

Trap Seal Protection (§901.2, §901.3) Every fixture trap must be protected against siphonage and backpressure. The vent system must be designed so no trap seal is exposed to a pressure differential exceeding 1 inch water column (0.24 kPa) on the outlet side of the trap.

Vent Sizing (§904.1) Vent size is determined by developed length and total fixture units connected, using Table 703.2. Minimum individual vent diameter is 1¼ inches and never less than one-half the diameter of the drain it serves.

Key Concepts

Fixture Trapping Rules (§1001.2) - Every fixture must be separately trapped by an approved liquid seal trap — no exceptions unless the fixture has an integral trap. - Only one trap per trap arm — no double-trapping. - Tailpiece (vertical distance from fixture outlet to trap weir): maximum 24 inches. - Shared trap allowance: One trap may serve up to 3 single-compartment sinks, laundry tubs, or lavatories if they are in the same room, outlets are no more than 30 inches apart, and the trap is centrally located. - Food waste disposers at commercial/restaurant/industrial sinks must connect to a separate trap. - Each domestic clothes washer and laundry tub needs a separate trap, except a laundry tub…

Chapter 11: Storm Drainage (2015 UPC / 2017 Idaho State Plumbing Code)

2 questions | 2% of exam

Key Concepts

Approved Materials (§1101.4) - Conductors in vents/shafts: Cast iron, galvanized steel, wrought iron, copper/copper alloy, lead, Sch. 40 ABS DWV, Sch. 40 PVC DWV, stainless steel 304 or 316L - Critical: Stainless steel 304 cannot be installed underground and must remain ≥6 inches aboveground - Leaders (outside): Per Table 701.2 standards, plus aluminum, galvanized steel, or copper sheet metal (§1101.4.3) - Underground building storm drains: Must comply with Table 701.2 underground DWV standards (§1101.4.4) - Subsoil drain pipe materials (Table 1101.4.6): PE (ASTM F405), PVC (ASTM D2729), or Vitrified Clay extra-strength (ASTM C4/C700)

Key Concepts

Scope and Coverage (Section 1201.0–1202.0) Chapter 12 governs fuel gas piping up to 5 psi (34 kPa) from the point of delivery to appliance connections. Coverage begins at the outlet of the service meter assembly or service regulator.

Acceptable Piping Materials and Joining Methods - Metallic pipe: Schedule 40 black steel or wrought iron; joined by threading, welding, or flanged fittings. Galvanized steel is not permitted underground. - Copper tubing: Types K and L acceptable for natural gas (not LP where copper is attacked); joined by brazing or flare fittings. Solder joints are not permitted on gas piping. - CSST (Corrugated Stainless Steel Tubing): Must be listed and installed per manufacturer instructions; requires arc-fault bonding to reduce…

Key Concepts

This topic tests your ability to read a schematic and apply UPC sizing tables systematically. You will be given a drawing and must extract fixture counts, developed lengths, and pressure data to size pipe, meters, drains, and vents.

Water Supply Sizing (Chapter 6): - Table 610.3 assigns Water Supply Fixture Units (WSFU) and minimum fixture branch pipe sizes. Each fixture type has a specific WSFU value (e.g., lavatory = 1 WSFU, water closet with flush tank = 3 WSFU, bathtub = 2 WSFU). - Table 610.10 assigns WSFU for flushometer valve fixtures. Flushometer water closets carry higher WSFU values (6 WSFU each) and cannot be served by pipe smaller than 1 inch at the branch. - **Table…

Key Concepts

What a Business Plan Is: A business plan is a written document describing the nature of the business, the sales and marketing strategy, the financial background, and containing a projected profit and loss statement. It is a living document — it continually changes and shows where you've been and where you want to go.

The Six Components of a Business Plan:

1. Executive Summary — A 1–2 page overview covering the business scope/purpose, industry description, and outlines of the management, marketing, operations, and financial plans. Must include: why the idea will work, a proprietary edge or advantage, specific financial goals (break-even analysis, pretax ROI, profit margin), and management track record. *Note: Profit margin = net profit after…

Key Concepts

Selecting an Accountant (CPA or LPA) - The Idaho State Board of Accountancy licenses and regulates both CPAs and LPAs — contact at (208) 334-2490 or www.isba.idaho.gov - Services include: tax returns, reviewing accounting systems, consulting on business problems, data processing systems, and helping apply for loans/credit - Fees are based on type of service and complexity of work — not a flat universal rate - An engagement letter is signed by both accountant and client to spell out fees, scope of work, and details before work begins — prevents misunderstandings - Find accountants through referrals from lawyers, bankers, and business associates

Idaho Plumbing Contractor Exam

Key Concepts

Sole Proprietorship - Owned and controlled by one person who is solely liable for all business obligations. No liability protection.

General Partnership - All partners participate fully in running the business and share equally in profits/losses. - If not operating under the full legal names of each owner, must file a Certificate of Assumed Business Name with the Idaho Secretary of State.

Limited Liability Partnership (LLP) - A partner is not liable for negligent acts committed by another partner or by an employee not under their supervision. - Formed by filing a Statement of Qualification of Limited Liability Partnership with the Idaho Secretary of State. - Existing general partnerships or individuals…

Idaho Plumbing Contractor Exam — 1% of Exam (1 Question)

Key Concepts

DOPL Mission The Division of Occupational and Professional Licenses (DOPL) exists to safeguard Idaho citizens through responsible administration of building/construction safety and licensure standards, while also promoting a positive business climate.

Seven Regulatory Boards Under DOPL DOPL hosts exactly seven boards within the Executive Office of the Governor:

1. Idaho Building Code Board
2. Idaho Electrical Board
3. Idaho Heating, Ventilation and Air Conditioning (HVAC) Board
4. Idaho Plumbing Board
5. Manufactured Housing Board
6. Modular Building Advisory Board
7. Public Works Contractors License Board

Idaho Plumbing Contractor Exam

Key Concepts

Bookkeeping Process (in order): 1. Business Transaction (check or invoice) → triggers a journal entry 2. Journal → records daily transactions; entries are totaled and transferred to the general ledger ("posting") 3. General Ledger → shows all financial transactions of the business 4. Trial Balance → confirms total debits equal total credits 5. Financial Statements → prepared from the trial balance

Financial Statements: - Balance Sheet → snapshot of assets, liabilities, and equity at a specific point in time. Formula: Assets = Liabilities + Equity. Indicates liquidity (ability to meet short-term obligations). - Income Statement → shows profit or loss over a reporting period only; does NOT show overall financial state.…

Idaho Plumbing Contractor Exam — Section 6 (20 questions, 20% of exam)

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Federal Anti-Discrimination Laws

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Types of Contractor Insurance

• Automobile Insurance: Covers bodily injury liability, property damage liability, vehicle operator liability, medical payments, collision, and comprehensive (non-collision damage/theft).
• Builder's Risk: Covers damage to the work itself during construction — includes materials intended for the project. Can be carried by owner or contractor. Two types: all-risk (most common) and named-peril.
• Commercial General Liability (CGL): Protects against third-party claims for bodily injury or property damage arising from construction operations.
• Completed Operations (Errors & Omissions): Covers injuries or property damage to third parties after the contractor finishes work. Requires maintaining a safe, hazard-free jobsite.
• Contractors Pollution Liability: Covers environmental claims typically excluded from general liability policies.
• **EPLI…

Idaho Plumbing Contractor Exam — 3 questions, ~3% of exam

Key Concepts

Open vs. Closed Bids (Public Works)

• Open bid (hard bid): Most common; all bidders use the same standardized proposal form. Price is final — no adjustments allowed. Bids are opened and read publicly.
• Closed bid: No standardized form. Not read publicly. Owners may interview contractors and negotiate a final price. Additional documentation may be submitted with the offer.
• Public works projects must by law be advertised for bids. Contractors must hold a licensed public works contractor status in Idaho to bid.

Idaho Plumbing Contractor Exam

Key Concepts

Essential Elements of a Valid Contract — All five must be present or the contract is unenforceable: 1. Offer and Acceptance — Clear, definite offer + unqualified acceptance 2. Consideration — Each party must promise or provide something of value 3. Parties — Must be adults of sound mind; contract must state names and addresses 4. Mutuality of Obligation — "Meeting of the Minds"; parties agree to the same thing, in the same sense, at the same time 5. Legal Purpose — Courts will not enforce contracts covering illegal acts

Key Concepts

Project Management Phases (know the correct order): 1. Initiation & Estimating — Defines nature and scope; includes business needs analysis, financial analysis, stakeholder analysis, and project definition 2. Planning — Determines methods, sequence, scheduling, budget, risk, and scope; ends with formal approval to begin work 3. Executing — Carrying out the planned work 4. Monitoring & Controlling — Tracking progress, detecting variances, taking corrective action 5. Closing — Project close and contract closure

⚠️ The manual lists the phases out of logical order (initiation, planning, monitoring & controlling, executing, closing). Know both the listed order and the logical sequence.

Idaho Plumbing Contractor Exam

Key Concepts

OSHA's General Duty Clause Employers must provide a workplace free from recognized hazards likely to cause death or serious physical harm. This applies even when no specific OSHA standard addresses the hazard.

Employer Recordkeeping Requirements Three core forms — know each one's purpose: - Form 300 – Log of Work-Related Injuries and Illnesses: Ongoing log classifying each incident by type and severity - Form 300-A – Summary of Work-Related Injuries and Illnesses: Annual summary, must be posted February 1–April 30 each year - Form 301 – Injury and Illness Incident Report: Filled out for each individual recordable incident

Idaho Plumbing Contractor Licensing Exam

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Income Tax Filing by Business Entity Type

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Right to Lien (Idaho Code § 45-501) A broad range of parties qualify: laborers, material suppliers, equipment renters/lessors, subcontractors, contractors, architects, professional engineers, and licensed surveyors. Work covered includes construction, alteration, repair, grading, filling, and professional services (plans, specs, surveys, on-site observation). Contractors, subcontractors, and anyone in charge of construction are deemed agents of the owner by law — meaning their contracts bind the owner's property to lien exposure.

Filing Requirements (§ 45-507) - File with the county recorder in the county where the property is located - Must be filed within 90 days after completion of labor, services, or material furnishing - Required contents: - Statement of demand (after credits and offsets) - Name of owner…