I85PREP
⌘ K
ICC P3 study materials
ICC P3 study resources

ICC P3 practice questions

One question at a time. Build your ICC P3 understanding.

First 50 of 200 questions. Each one lists the choices, the correct answer, and an explanation. The checker at the top of this page saves progress in this browser when it is available.

Continue in the practice tool above to load more questions, 50 at a time.

Question 1General Administration and Plumbing Plan Review Fundamentals

A property owner plans to install a new water service line to a building. Before work begins, what must generally be obtained from the code official?

  1. A zoning approval from the planning board
  2. A plumbing permit authorizing the work Correct answer.
  3. A variance from the board of appeals
  4. A certificate of occupancy for the building

Explanation

Code administration provisions require a permit before installation of plumbing systems and appurtenances, including water service lines, so the work can be reviewed and inspected. Permits are issued only after the required construction documents are reviewed and approved. Zoning and occupancy approvals address different regulatory concerns.

Question 2General Administration and Plumbing Plan Review Fundamentals

Plumbing construction documents submitted for review must show, at a minimum, the location and size of which of the following?

  1. The owner's insurance certificates for the project
  2. Water service, drainage and vent piping Correct answer.
  3. The contractor's bid documents and payment schedule
  4. The maintenance budget for the plumbing system

Explanation

Submitted plans must contain enough information for the code official to determine code compliance, which includes the location, size and arrangement of the water service, drainage and vent piping and the fixtures served. Financial and insurance documents are not technical submittals and play no part in the code review.

Question 3General Administration and Plumbing Plan Review Fundamentals

In the plumbing code, the term "code official" refers to the officer or other designated authority charged with which of the following?

  1. Designing the plumbing systems installed in the jurisdiction
  2. Administration and enforcement of the code Correct answer.
  3. Supplying potable water to each building served
  4. Installing and inspecting plumbing on behalf of owners

Explanation

The code official is the authority charged with administering and enforcing the code, including plan review, permit issuance and inspection. The code official does not perform design work or installation, and is not the water purveyor. Design responsibility stays with the registered design professional or the contractor of record.

Question 4General Administration and Plumbing Plan Review Fundamentals

Under typical code administration provisions, when must the permit holder notify the code official regarding work that is ready for inspection?

  1. Only after the entire system is placed in service
  2. At the time the work is ready for inspection Correct answer.
  3. Within one year of the permit being issued
  4. At the close of the project, with a written final report

Explanation

The code requires the permit holder to give notice when work is ready for inspection so that required inspections, such as rough-in and final, can be performed in sequence. Work may not be concealed before it is inspected and approved. Notice given after concealment or after the system is energized defeats the purpose of the inspection.

Question 5General Administration and Plumbing Plan Review Fundamentals

A certificate of occupancy issued for a new building indicates which of the following?

  1. The plumbing plans have been reviewed by the code official
  2. The contractor has paid all permit and inspection fees
  3. The building may lawfully be occupied for its intended use Correct answer.
  4. The water purveyor has approved the meter installation

Explanation

A certificate of occupancy is issued after the required inspections and approvals confirm that the structure complies with the code and may be used for the intended occupancy. Plan review and fee payment are earlier steps and do not, by themselves, authorize occupancy. Utility approvals are separate from the building occupancy approval.

Question 6General Administration and Plumbing Plan Review Fundamentals

Which of the following plumbing activities typically may be performed without first obtaining a plumbing permit?

  1. Installing an additional water closet in a dwelling unit
  2. Repairing a leaking faucet in a single-family dwelling Correct answer.
  3. Replacing an underground building sewer line
  4. Installing a new electric storage water heater

Explanation

Code administration provisions exempt minor repair and maintenance work, such as stopping a faucet leak, from the permit requirement. Installing new fixtures, replacing a building sewer and installing a water heater are regulated installations that require a permit and inspection. The exemption is narrow and does not extend to work involving new piping or appliances.

Question 7General Administration and Plumbing Plan Review Fundamentals

A plan reviewer finds that the submitted drawings omit the size and location of the water service. What is the most appropriate action?

  1. Approve the plans and require the contractor to submit a letter later
  2. Issue the permit, since water service sizing is chosen in the field
  3. Approve the plans and note the deficiency for the field inspector
  4. Return the plans for correction before approval is granted Correct answer.

Explanation

Approval may be granted only when the construction documents contain sufficient information for the code official to determine compliance. Missing sizing and routing information prevents that determination, so the submittal is returned for correction. Deferring required design information to the field or to a later letter undermines the plan review process.

Question 8General Administration and Plumbing Plan Review Fundamentals

A contractor proposes a pipe material that is not listed in the code. For the code official to approve its use, the contractor must generally do which of the following?

  1. Submit evidence that the material conforms to the code's intent Correct answer.
  2. Obtain a letter from the manufacturer's sales office
  3. Wait until the code is amended to include the material
  4. Install it and request approval at final inspection

Explanation

The code permits alternative materials, methods and equipment to be approved when the code official finds, from submitted evidence or tests, that the proposed alternative is equivalent in quality, strength, effectiveness and safety to the prescribed provisions. Approval must precede installation. Manufacturer marketing correspondence alone is not sufficient technical evidence.

Question 9General Administration and Plumbing Plan Review Fundamentals

A permit applicant disagrees with an interpretation issued by the code official. To whom may the applicant appeal?

  1. The plumbing inspector who performed the inspection
  2. The water utility that serves the building
  3. The board of appeals established for that purpose Correct answer.
  4. The manufacturer of the disputed plumbing product

Explanation

The code provides a formal appeal process through a board of appeals that hears challenges to decisions and interpretations of the code official. Appeals must be filed within the time and in the manner the code prescribes. Utilities, product manufacturers and individual inspectors have no authority to overturn the code official's determinations.

Question 10General Administration and Plumbing Plan Review Fundamentals

Under the code, a plumbing permit becomes invalid where the authorized work has not been commenced within what period after permit issuance?

  1. 30 days after the permit is issued
  2. 365 days after the permit is issued
  3. 180 days after the permit is issued Correct answer.
  4. Two years after the permit is issued

Explanation

Permits expire when the work is not commenced within 180 days of issuance, and also when the work is suspended or abandoned for 180 days. This provision keeps the approved documents current with the code in effect and clears inactive permits from the record. Shorter or longer periods do not reflect the standard expiration rule.

Question 11General Administration and Plumbing Plan Review Fundamentals

Plumbing plans must show how penetrations of fire-resistance-rated assemblies will be protected because:

  1. the fire rating of the assembly must be maintained Correct answer.
  2. all piping within rated walls must be concealed
  3. such assemblies may not contain any piping at all
  4. piping must be isolated from the building structure

Explanation

Where piping passes through a wall or floor assembly required to be fire-resistance rated, the penetration must be protected so the rating of the assembly is not reduced. The plans should identify the rated assemblies and the protection method proposed. Concealment is not the objective, and piping is not categorically prohibited in rated assemblies.

Question 12General Administration and Plumbing Plan Review Fundamentals

A water closet shall be located not less than what distance from its centerline to any sidewall or partition?

  1. 12 inches
  2. 30 inches
  3. 24 inches
  4. 15 inches Correct answer.

Explanation

The code requires a water closet to be set not less than 15 inches from its centerline to a sidewall or partition, measured to provide usable space for the occupant. The fixture space must also meet the required minimum width. These clearances are verified during plan review of the fixture layout.

Question 13General Administration and Plumbing Plan Review Fundamentals

A storage-type water heater must be provided with which of the following?

  1. A temperature and pressure relief valve Correct answer.
  2. A check valve on the relief discharge pipe
  3. A pressure-reducing valve on the outlet
  4. A vacuum breaker on the cold water inlet

Explanation

Storage water heaters must be protected against excessive temperature and pressure by an approved relief valve, with the discharge piped to an approved location. Valves or obstructions that could block the relief discharge are not permitted. The relief device is a safety requirement checked during plan review and inspection.

Question 14General Administration and Plumbing Plan Review Fundamentals

A lawn irrigation system connected to a potable water supply must be protected by which of the following?

  1. An approved backflow prevention assembly Correct answer.
  2. A pressure gauge on the service line
  3. A water meter with a strainer upstream
  4. A check valve installed at every sprinkler head

Explanation

Connections that could allow nonpotable water to enter the potable supply must be protected by an approved backflow prevention assembly appropriate to the degree of hazard. Irrigation systems present a cross-connection hazard and require this protection at the connection. Meters, gauges and head-mounted check valves do not provide the required protection.

Question 15General Administration and Plumbing Plan Review Fundamentals

Horizontal drainage piping of 2-1/2 inches nominal diameter or smaller shall be sloped at not less than which rate?

  1. 1/8 inch per foot
  2. 1 inch per foot
  3. 1/2 inch per foot
  4. 1/4 inch per foot Correct answer.

Explanation

Small-diameter horizontal drainage piping must be installed with a uniform slope of not less than 1/4 inch per foot so that solids are carried and the pipe is scoured. Larger drainage piping may be permitted a lesser slope where the code allows. Flatter slopes on small pipe are not permitted because they promote clogging.

Question 16General Administration and Plumbing Plan Review Fundamentals

The liquid seal of a fixture trap shall be not less than:

  1. 2 inches and not more than 4 inches Correct answer.
  2. 3 inches and not more than 5 inches
  3. 1 inch and not more than 2 inches
  4. 4 inches and not more than 6 inches

Explanation

A fixture trap must maintain a liquid seal of at least 2 inches to resist sewer gas passage, and no more than 4 inches to avoid sluggish flow and excessive retention. Trap design and installation are reviewed to confirm the seal depth falls within this range. Depths outside the range either fail to seal reliably or impair drainage.

Question 17General Administration and Plumbing Plan Review Fundamentals

A vent pipe extending through a roof must terminate not less than what distance above the roof surface?

  1. 6 inches Correct answer.
  2. 4 inches
  3. 12 inches
  4. 24 inches

Explanation

Vent terminals must extend at least 6 inches above the roof and be unobstructed, with additional height required for certain roof uses or where snow accumulation is a factor. The purpose is to keep the vent opening clear of the roof surface and away from contamination. Lower terminations can be blocked by snow, debris or ponding.

Question 18General Administration and Plumbing Plan Review Fundamentals

The minimum size of a building water service pipe is determined primarily from which of the following?

  1. The diameter of the building sewer pipe
  2. The total floor area of the building only
  3. The number of occupants assigned to each floor
  4. The fixture unit load and the available pressure Correct answer.

Explanation

Water service sizing is based on the total demand expressed in fixture units, the length of piping, the developed length, and the pressure available at the source, so that minimum residual pressure is maintained at the fixtures. Floor area, occupant counts and the sewer diameter are not the sizing basis. The sizing method and result must be shown on the plans.

Question 19General Administration and Plumbing Plan Review Fundamentals

Under the code, plumbing fixtures, devices and appurtenances shall be maintained in what manner?

  1. Only when a complaint is filed with the code official
  2. In a sanitary and safe condition at all times Correct answer.
  3. At the discretion of the building owner's insurer
  4. Only until the certificate of occupancy is issued

Explanation

The code imposes a continuing duty to keep plumbing systems in a sanitary and safe condition and in proper working order for the life of the building. Maintenance obligations do not end with the certificate of occupancy and are not triggered by complaints alone. Enforcement may follow if a system is allowed to deteriorate.

Question 20General Administration and Plumbing Plan Review Fundamentals

A plumbing permit application is reviewed for compliance with which edition of the plumbing code?

  1. The most recent edition published anywhere
  2. The edition in effect when the building is first occupied
  3. The edition in effect on the permit application date Correct answer.
  4. The edition the contractor prefers to use

Explanation

The code edition legally adopted by the jurisdiction and in effect on the date of application governs the review, unless a specific provision states otherwise. This gives applicants a fixed standard and prevents shifting requirements during review. Later editions become applicable only when formally adopted.

Question 21General Administration and Plumbing Plan Review Fundamentals

Approved plumbing plans and specifications shall be:

  1. Filed with the contractor's licensing board
  2. Kept at the job site until the work is completed Correct answer.
  3. Retained by the manufacturer of the fixtures
  4. Mailed to the water purveyor before work begins

Explanation

The approved documents must remain available at the site of the work so that the inspector can compare the installation with what was approved. Where the code official retains one set, the permit holder keeps the other at the site. Removal of the approved plans from the job site hinders required inspections.

Question 22General Administration and Plumbing Plan Review Fundamentals

The minimum number of plumbing fixtures required for a new commercial building is determined from which of the following?

  1. The size of the water service and building sewer
  2. The occupancy classification and the occupant load Correct answer.
  3. The number of plumbing contractors working on site
  4. The building's construction type and height

Explanation

Minimum fixture requirements are established by tables keyed to the occupancy classification and the calculated occupant load, with separate provisions for men and women and for accessible fixtures. A plan reviewer confirms the occupant load calculation and the resulting fixture count. Pipe sizes and construction type do not establish the required fixture count.

Question 23General Administration and Plumbing Plan Review Fundamentals

For a multi-story building, plumbing plans should include a riser diagram because it:

  1. establishes the contract price for the plumbing work
  2. shows vertical relationships of drain, vent and water piping Correct answer.
  3. certifies that fixtures meet the code's water use limits
  4. replaces the need for a floor plan of each story

Explanation

A riser diagram depicts how drainage, vent and water piping stack and connect vertically through the building, which is essential for reviewing venting, drainage and pressure requirements. It supplements, rather than replaces, the floor plans. Pricing and fixture water-use certification are separate matters.

Question 24General Administration and Plumbing Plan Review Fundamentals

Under typical code administration provisions, who is responsible for ensuring that the installation conforms to the approved plans and the code?

  1. The licensed contractor holding the permit Correct answer.
  2. The supplier of the plumbing fixtures
  3. The code official who approved the plans
  4. The owner of the building in all cases

Explanation

The permit holder is responsible for performing the work in accordance with the approved documents and the code, and inspections verify that performance. The code official enforces the code but does not supervise or perform the installation. Suppliers provide listed materials but do not control field installation.

Question 25General Administration and Plumbing Plan Review Fundamentals

Before a newly installed plumbing system is placed in operation, the permit holder must do which of the following?

  1. Wait 30 days after the last rough-in inspection
  2. Obtain approval following the required final inspection Correct answer.
  3. Submit as-built drawings to the water purveyor
  4. Notify the fixture manufacturers that work is complete

Explanation

A plumbing system may not be placed in use until the required inspections, including the final inspection, have been completed and approved. Approval confirms that the installed work matches the approved documents and applicable code provisions. A waiting period or notifications to outside parties do not substitute for that approval.

Question 26General Administration and Plumbing Plan Review Fundamentals

After the drain, waste and vent rough-in is complete in a wall but before the wall is closed, the permit holder must:

  1. notify the water utility that the system is ready for service
  2. schedule the final inspection for the entire building
  3. submit as-built drawings to the code official for filing
  4. obtain an inspection and approval of the rough-in Correct answer.

Explanation

Plumbing work that will be concealed by building finish must be inspected and approved while it is still exposed. The permit holder is responsible for requesting that inspection before covering the piping, so the code official can verify compliance with the approved plans and the code.

Question 27General Administration and Plumbing Plan Review Fundamentals

All plumbing work on a new building is complete and the final inspection has been approved. What does the code official typically issue at this point?

  1. a notice of violation listing corrections
  2. a plumbing permit for the next phase of work
  3. a stop work order closing the site
  4. a certificate of occupancy or final approval Correct answer.

Explanation

Once the installation has passed its final inspection and the work matches the approved plans, the jurisdiction may allow the building to be used by issuing a certificate of occupancy or equivalent final approval. Occupancy before that approval is generally prohibited.

Question 28General Administration and Plumbing Plan Review Fundamentals

A code official reviews submitted plumbing plans and finds they do not conform to the adopted plumbing code. The official should:

  1. forward the plans to the board of appeals for a ruling
  2. approve the plans with an oral warning to the installer
  3. issue the permit and rely on field inspections to catch the problems
  4. return the plans with written reasons for disapproval Correct answer.

Explanation

When a plan review reveals noncompliance, the standard administrative practice is to withhold approval and return the plans with a written statement of the deficiencies. Written reasons give the applicant a clear basis to revise the submittal and preserve the record if the decision is appealed.

Question 29General Administration and Plumbing Plan Review Fundamentals

During construction, an installer finds that a soil pipe must be relocated from the position shown on the approved plans. The permit holder should:

  1. install the pipe as relocated and note it on the site copy of the plans
  2. explain the change to the code official at the final inspection
  3. obtain approval of revised plans before making the change Correct answer.
  4. ask the board of appeals for a variance from the approved plans

Explanation

Approved plans govern the installation, so a substantive change in layout requires revised plans to be submitted and approved before the altered work is installed. Field notes on a working copy do not amend an approved set of drawings.

Question 30General Administration and Plumbing Plan Review Fundamentals

Before issuing a plumbing permit to a contractor, a jurisdiction will ordinarily confirm that the contractor:

  1. carries a surety bond equal to the contract value
  2. has finished five similar projects locally
  3. holds a valid license or registration accepted by the jurisdiction Correct answer.
  4. owns a service truck stocked with approved fittings

Explanation

Permits are issued only to persons legally qualified to do the work, which in most jurisdictions means a contractor licensed or registered under state or local law. The licensing check protects the public by ensuring the permit holder is accountable to a regulatory authority.

Question 31General Administration and Plumbing Plan Review Fundamentals

An inspector observes plumbing being installed in an unsafe manner that departs from the approved plans. What action may the code official take?

  1. Revoke the contractor's license on the spot without a hearing.
  2. Let the work continue if the installer promises to fix it later.
  3. Issue a stop work order until the violation is corrected. Correct answer.
  4. Ask the water utility to disconnect service to the block.

Explanation

Code officials have authority to halt work that is proceeding in violation of the code or the approved plans. A stop work order remains in effect until the defective work is corrected and the required inspections are passed.

Question 32General Administration and Plumbing Plan Review Fundamentals

A newly installed potable water distribution system must be proved tight. Which test is normally required for this purpose?

  1. a vacuum test held for one hour
  2. a smoke test of the entire system
  3. a dye test performed at the lowest fixture
  4. a water test under pressure not less than the working pressure Correct answer.

Explanation

Water distribution piping is tested with water under pressure at least equal to the working pressure of the system and held for the required duration to show that joints and connections are tight. An air test may be permitted in limited circumstances where approved, but the water pressure test is the baseline requirement.

Question 33General Administration and Plumbing Plan Review Fundamentals

Which circumstance typically supports suspension or revocation of an issued plumbing permit?

  1. The owner changes the bathroom finish schedule.
  2. The property is sold and the buyer keeps the same contractor.
  3. The work proceeds in violation of the code or approved plans. Correct answer.
  4. The contractor requests an inspection earlier than scheduled.

Explanation

Permits may be suspended or revoked where the work is not being done in accordance with the approved plans or the code, or where the permit was obtained improperly. The remedy protects the public by stopping construction that cannot lawfully be approved.

Question 34General Administration and Plumbing Plan Review Fundamentals

A code official approves plumbing plans that later prove to contain an error violating the code. What is the correct legal effect of the approval?

  1. The error must be corrected, because plan approval does not waive code compliance. Correct answer.
  2. The permit holder may treat the approval as a permanent waiver of that code requirement.
  3. The approved plans control, so the work may follow them even if they conflict with the code.
  4. The approval ends the official's duty to inspect the plumbing work.

Explanation

Approval of plans is an administrative step and does not relieve the permit holder of the obligation to install work that complies with the code. An erroneous approval must be corrected through revised plans and inspection, and the underlying code requirement still governs.

Question 35Plumbing Fixtures and Fixture Fittings

What is the minimum liquid seal depth permitted for a fixture trap?

  1. 2 inches Correct answer.
  2. 2-1/2 inches
  3. 4 inches
  4. 3 inches

Explanation

The plumbing code requires each trap to hold a liquid seal of not less than 2 inches, measured between the trap weir and the top of the trap dip. This depth resists evaporation and normal pressure fluctuations in the drainage system. Deeper seals are allowed only up to the code maximum.

Question 36Plumbing Fixtures and Fixture Fittings

What is the maximum liquid seal depth permitted for a fixture trap?

  1. 4 inches Correct answer.
  2. 6 inches
  3. 2 inches
  4. 5 inches

Explanation

Trap seals are limited to a maximum of 4 inches because an excessively deep seal holds a large volume of waste that can turn septic and is more easily lost by siphonage. The 4 inch cap works together with the 2 inch minimum to define the acceptable seal range.

Question 37Plumbing Fixtures and Fixture Fittings

What is the maximum water consumption permitted for a water closet?

  1. 3.5 gallons per flush
  2. 1.28 gallons per flush
  3. 1.6 gallons per flush Correct answer.
  4. 1.0 gallon per flush

Explanation

The code table of maximum fixture flow rates and consumption caps a water closet at 1.6 gallons per flush. Lower consumption values such as 1.28 gallons per flush are permitted because they are more restrictive, but they are not the ceiling.

Question 38Plumbing Fixtures and Fixture Fittings

What is the maximum flow rate permitted for a showerhead?

  1. 2.0 gpm at 60 psi
  2. 2.5 gpm at 60 psi
  3. 1.5 gpm at 60 psi
  4. 2.5 gpm at 80 psi Correct answer.

Explanation

The code caps showerheads at 2.5 gallons per minute when tested at a flowing pressure of 80 psi. The test pressure matters because a showerhead flowing at 60 psi would deliver less water than the same device tested at 80 psi.

Question 39Plumbing Fixtures and Fixture Fittings

What is the maximum flow rate permitted for a lavatory faucet in a private bathroom?

  1. 2.2 gpm at 60 psi Correct answer.
  2. 2.5 gpm at 80 psi
  3. 0.5 gpm at 60 psi
  4. 1.5 gpm at 60 psi

Explanation

A private lavatory faucet is limited to 2.2 gallons per minute at a flowing pressure of 60 psi. Public lavatories are held to a much lower rate because they are metered or restricted for high-frequency use.

Question 40Plumbing Fixtures and Fixture Fittings

What is the maximum water delivery permitted for a metering faucet in a public lavatory?

  1. 2.2 gallons per cycle
  2. 1.0 gallon per cycle
  3. 0.5 gallon per cycle
  4. 0.25 gallon per cycle Correct answer.

Explanation

Metering faucets are rated per activation cycle rather than per minute, and the code limits them to 0.25 gallon per cycle. This recognizes that a metering faucet runs for a fixed short interval each time it is used.

Question 41Plumbing Fixtures and Fixture Fittings

What is the minimum size of a fixture drain serving a water closet?

  1. 1-1/4 inches
  2. 2 inches
  3. 4 inches
  4. 3 inches Correct answer.

Explanation

A water closet discharges a large volume of solids quickly, so its fixture drain must be at least 3 inches in diameter. Smaller drains used for lavatories and tubs are not adequate for the solids load of a water closet.

Question 42Plumbing Fixtures and Fixture Fittings

In which location is a drinking fountain prohibited from being installed?

  1. In a break room
  2. In a corridor
  3. In a toilet room Correct answer.
  4. In a lobby

Explanation

Drinking fountains must be located where sanitary conditions can be maintained, and the code expressly prohibits installing them in toilet rooms. Corridors, lobbies and break rooms are acceptable locations provided clearances and access are met.

Question 43Plumbing Fixtures and Fixture Fittings

A clothes washer standpipe receptor must extend a minimum of what distance above its trap weir?

  1. 18 inches Correct answer.
  2. 24 inches
  3. 36 inches
  4. 30 inches

Explanation

The standpipe must rise at least 18 inches above the trap weir so the washer's discharge does not splash out, and no more than 30 inches so the water does not overpressurize the trap. The 18 inch figure is the minimum of that range.

Question 44Plumbing Fixtures and Fixture Fittings

What is the maximum developed length of a trap arm connected to a 1-1/2 inch trap?

  1. 5 feet
  2. 8 feet
  3. 6 feet Correct answer.
  4. 12 feet

Explanation

The distance a trap arm may run between the trap weir and its vent is tabulated by trap size. A 1-1/2 inch trap arm is limited to 6 feet of developed length, while smaller traps get less and larger traps get more.

Question 45Plumbing Fixtures and Fixture Fittings

A fixture outlet with an effective opening of 2 inches discharges to a receptor. What is the minimum required air gap?

  1. 1 inch
  2. 8 inches
  3. 2 inches
  4. 4 inches Correct answer.

Explanation

An air gap must be at least twice the effective opening of the outlet, and never less than 1 inch. Doubling a 2 inch effective opening gives 4 inches, which controls because it is greater than the 1 inch floor.

Question 46Plumbing Fixtures and Fixture Fittings

How shall the discharge from a domestic dishwasher be connected to the drainage system?

  1. Through a trap with a 2 inch seal
  2. By direct connection to the sink tailpiece
  3. By direct connection to the building drain
  4. Through an air gap or air break Correct answer.

Explanation

Dishwasher discharge carries food solids and is connected indirectly so that a backed-up drain cannot siphon waste water back into the appliance. The code permits either an air gap or an air break to provide that separation.

Question 47Plumbing Fixtures and Fixture Fittings

What is the minimum size of a water closet compartment that is not required to be accessible?

  1. 36 inches wide by 72 inches deep
  2. 36 inches wide by 60 inches deep
  3. 30 inches wide by 60 inches deep Correct answer.
  4. 30 inches wide by 48 inches deep

Explanation

The code sets the minimum water closet compartment at 30 inches in width and 60 inches in depth. Larger compartments and the greater dimensions used for accessible compartments are permitted but are not the minimum.

Question 48Plumbing Fixtures and Fixture Fittings

A floor drain trap that is subject to evaporation because the drain is used infrequently shall be provided with:

  1. A backwater valve
  2. A vented loop
  3. A deeper trap seal of 6 inches
  4. A trap seal primer Correct answer.

Explanation

Evaporation from an unused trap destroys the seal and allows sewer gas into the building, so the code requires a trap seal primer to replenish the trap. The primer maintains the seal automatically between periods of fixture use.

Question 49Plumbing Fixtures and Fixture Fittings

At what minimum slope shall the floor of a shower be pitched toward the drain?

  1. 1/4 inch per foot Correct answer.
  2. 1/8 inch per foot
  3. 1/2 inch per foot
  4. 3/16 inch per foot

Explanation

Shower floors must slope at least 1/4 inch per foot toward the drain so water drains freely without ponding. The slope may be increased up to 1/2 inch per foot but may not be less than the 1/4 inch minimum.

Question 50Plumbing Fixtures and Fixture Fittings

What is the maximum water temperature permitted at a shower outlet where a temperature limiting device is installed?

  1. 130°F
  2. 120°F Correct answer.
  3. 115°F
  4. 110°F

Explanation

Shower valves must be equipped with a device that limits the water delivered to the showerhead to a maximum of 120°F. This protects bathers from scald injury when the valve is moved or when supply pressure changes.