Master Plumber Practice Exam - 2024 Codes

Of the possible answers, only a licensed code officer who is an authority having jurisdiction is the one who is allowed to interpret the code. (IPC 104.2; UPC 103.1). Whether a plumbing installation passes or fails an inspection is subject to a code officer's interpretation. You can appeal a decision that you feel is incorrect or questionable. Even as a master plumber your understanding of the intent of the code is not absolute. The plumbing inspector is the final word in the field when it comes to an interpretation of the code.

Pipe and fixtures to be replaced require a permit. (IPC 105.2; UPC 104.2; 502.1). A water closet may be removed and reinstalled in order to clear a stoppage, replace a leaking wax seal or after a new floor has been installed but a water closet cannot be replaced without a permit.

True - Approved plans and specifications are required for every major job. (IPC 105.5.7; UPC 104.4.6). These documents are required to be stored on the job site. You must have them available to code officers on demand.

False - The plumbing code allows homeowners to obtain plumbing permits for work to be done on their own residences when the homeowners will do the work themselves. (IPC 105.3; UPC 104.3). When homeowners obtain a permit, they must do the work themselves. This policy sometimes only applies to the homeowner's primary residence.

The application for a plumbing permit requires key information that you, as the master plumber applying for the permit, must supply. Information needed for the application will include the following:
• Applicant's full name
• Applicant's complete address
• A full description of all work to be performed
• The number of plumbing fixtures to be installed
• The type of plumbing fixtures to be installed
• The type of use of the structure where the plumbing is being installed
• Additional data may also be required, such as your plumbing license number, detailed plans and specifications and so forth.

When you send a crew in to repair or alter existing plumbing you must take into consideration that the existing system shall not be made unsafe or altered in any way that will have a negative effect on the performance of the plumbing. (IPC 102.4; UPC 102.2).

True - It is allowable to use plumbing materials that have been used previously under certain conditions. (IPC 1409.1). The plumbing materials must be of an approved type. All of the material must be in good working order. You should seek approval from a plumbing code officer to approve the specified materials. If these conditions are met, it is allowable to reuse previously used plumbing parts and fixtures.

Pipe and fixtures to be replaced require a permit. (IPC 105.2; UPC 104.2; 502.1). Pipe and fixtures may be removed and reinstalled in order to clear a stoppage, replace a leaking wax seal or after a new floor has been installed but piping and fixtures cannot be replaced without a permit.

False - Municipalities generally restrict plumbers from working on municipal plumbing components. (IPC 109.3; 114.6.3; UPC 105.4, 106.5). It is common for municipalities to provide a variety of plumbing devices that can include piping, water meters, pressure-reducing valves, piping, fittings and other devices. Generally, a plumber is required to work on systems within five feet of a building foundation. However, some cities install equipment within a foundation. When this is the case, plumbers are responsible for work done beyond the installation.

When you apply for a plumbing permit you must provide a full description of the work to be done. (IPC 105.3; UPC 104.3). Plumbing plans are often required for larger jobs. Specifications of all materials to be installed are a common requirement for a plumbing permit. Permit applications require the physical address of the property to receive plumbing services. The use of the property is often required. It makes a difference if a structure is a home or a daycare. The owner's name of the proper is generally required. You are also required to detail the number and type of plumbing fixtures to be installed.

Your plumbing permit can be rendered invalid if work is not started within six months from the day that the permit is issued. (IPC 105.5.3; UPC 104.4.3). Don't panic. Most code officers will work with you if there are situations beyond your control that delay the start of the work. A code officer has some latitude in this matter. If you have a valid reason for your inability to begin work, you are likely to be awarded an extension.

False - Plumbing alterations should comply with current code requirements. The alterations made must be in compliance with present code requirements. However, the remainder of the existing plumbing system is not required to be upgraded to modern code requirements. (IPC 102.4; UPC 102.2).

True - Plumbing codes require different minimum standards for various types of building uses. For example, the minimum number of fixtures required for a building can vary substantially based on the use of a building. Accessibility requirements that do not apply to a residence can apply to an office building or business. There are several situations where everything from pipe sizing to the number of fixtures required can be different for various types of building uses. In order to change the use of a building within compliance to code requirements a plan and specifications must be submitted to the code enforcement office for approval.

The main purpose of a plumbing code is to safeguard the health, safety, property and public welfare of a community. It becomes legally enforceable when it is adopted by a governing body with jurisdiction.

A plumbing code official has the responsibility for establishing that the residences and commercial buildings in the community are designed and constructed in such a way to be reasonably free from hazards associated with the presence and use of plumbing appliances, appurtenances, fixtures and systems.

The code is intended to establish a minimum acceptable standard for plumbing material and installation so that the public welfare is maintained.

A plumbing inspection must be done before an occupancy permit can be issued. It is unlawful to make any change in the occupancy of a building without approval of a code official. (IPC 102.5; UPC 102.6). The code official must certify that the structure meets the provisions of the law governing the plumbing code and that any change does not result in hazards to the public health, safety or welfare.

Buildings that have been relocated are subject to the requirements of the code as if they were new construction. (IPC 102.7; UPC 102.7). Placing a building where one did not previously exist is analogous to construction a new building. It is the intent of plumbing code to require alteration of the existing plumbing systems to the extent necessary to bring them into compliance with the provision of the plumbing code applicable to new construction and make the existing plumbing system comply.

The provisions of a local plumbing code will not be deemed to supersede state or federal law unless they exceed the requirements of the state or federal law, making the local requirement more stringent. (IPC 102.1; UPC 102.1). This occurs only if the state or federal authority permits preemption.

The chief appointing authority, as determined jurisdiction-by-jurisdiction, is responsible for hiring all plumbing code officials. (IPC 103.2; UPC 103.1).

New construction or renovation designs may propose alternative materials, designs or methods of construction that are not described or addressed by the plumbing code. To use an alternative material, design or method of construction, an application must be made to the code official. (IPC 104.2.3.2; UPC 301.3).

The codes use an equivalency standard to determine if an alternative material, design or method of construction is acceptable to be used in construction or renovation. (IPC 104.2.3.4; UPC 301.3). A code official may require testing of the proposed alternative or other form of substantiation, like research reports. For the alternative material, design or method of construction to be approved, it must be proven to be not less than equivalent to those materials, designs and methods of construction set forth in the code. The criteria to determine equivalence includes the factors of quality, strength, effectiveness, durability and safety, including fire safety.

When a plumbing issue arises that impacts the strength, stability or operation of the plumbing system, and the issue is not covered by the plumbing code or manufacturer's instructions, the matter is to be decided by the code official. (IPC 102.9; UPC 103.1).

New construction or renovation designs may propose alternative materials, designs or methods of construction that are not described or addressed by the plumbing code. To use an alternative material, design or method of construction, an application must be made to the code official. (IPC 104.2.3.2; UPC 301.3).

The codes use an equivalency standard to determine if an alternative material, design or method of construction is acceptable to be used in construction or renovation. (IPC 104.2.3.4; UPC 301.3). A code official may require testing of the proposed alternative or other form of substantiation, like research reports. For the alternative material, design or method of construction to be approved, it must be proven to be not less than equivalent to those materials, designs and methods of construction set forth in the code. The criteria to determine equivalence includes the factors of quality, strength, effectiveness, durability and safety, including fire safety.

There are three critical stages for inspections of construction by code officials: (1) underground inspection of trenches or ditches with piping before backfill is put in place; (2) rough-in inspection after the framing and water supply and drainage piping is roughed-in; and (3) final inspection when all the work is complete and the plumbing system connected and ready for occupancy. (IPC 111.2; UPC 105.2).

All new installations are required to comply with the plumbing code. Other elements that may be required to meet current code requirements can include renovations, the replacement of fixtures, additions to a plumbing system and extensive repairs to plumbing systems. At no time can work done to a plumbing system make it unsafe or be detrimental to the system.

A plumbing permit will be required for the direct replacement of a kitchen sink. (IPC 105.2; UPC 104.2; 502.1). Fixtures may be removed and reinstalled in order to clear a stoppage, replace a leaking wax seal or after a new floor has been installed but piping and fixtures cannot be replaced without a permit. Existing plumbing will not be required to be brought up to current code standards, unless there is a health or safety issue. (IPC 102.4; UPC 102.2).

Annual inspections are required for backflow assemblies. (IPC 312.11.1; UPC 603.4.2). Each backflow preventer should be tested during the inspection. They must be working properly and must not allow contamination to the water source in a water distribution system. New installations are required to be inspected. Any need to repair a backflow preventer triggers the need for a test and inspection of the repaired device.

True - Code officers generally require a site plan and specifications on file before any work is commenced on an existing water service or sewer. The location of existing piping and the proposed location for new piping should all be included on the site plan. You should expect the sanitary district and the local water purveyor to be involved as well.

Adding new plumbing fixtures can overload existing plumbing. You must compute the total fixture-unit ratings and the demand that it will put on existing plumbing piping. It is possible that an existing pipe might have to be removed and replaced with a larger pipe.

Code officers are authorized to issue and post stop work orders when any work is being done contrary to the provisions of the code and where immediate danger is present, possible or pending. (IPC 115.1; UPC 106.4). Minor violations will not usually result in a stop work order, but the code officer will direct the minor violation to be brought into compliance. Code violations must be serious to be considered contrary to the code. When a stop work order is posted all work on a site must cease. The stop work order will bear the name of the issuing inspector. You should contact the inspector to determine what must be done to allow work to begin again. Do not continue to work if a stop work order has been posted. The penalties can be steep if you do.

Engineered trusses limit your ability to route piping. Trusses that are engineered must not be cut, notched, drilled, spliced or otherwise altered. (IPC 307.5; UPC 312.2). If any alteration of a truss is essential, an engineer should be consulted to render specific instructions on what may be done to accommodate a plumbing installation.

False - If you will be installing piping that will penetrate a fire-rated wall, you will have to work from approved plans and specifications. These documents will detail the acceptable manner in which to seal the voids around piping. (IPC 307.4, 315; UPC 312.7, 312.10.3).

Buried pipes are required to have a minimum depth of coverage that is equal to one foot in depth. (IPC 306.3; UPC 312.3). The material used to cover the pipe is required to be clean of anything that might damage the pipe as the backfill material is installed. You must compact the fill over the piping to avoid settling. Most plumbing contractors backfill six inches of dirt at a time. Then the dirt is compacted. Once the first level is compacted a second layer is installed and compacted. This completes the minimum requirements for backfilling a buried pipe.

Plumbing installations in potential flood areas require special consideration. (IPC 305., 309.1; UPC 301.4). The systems must be protected in ways that will prevent damage from flooding. Protection requirements call for the consideration of hydrostatic load and stress, hydrodynamic loads and stress, flooding of the piping in the plumbing system and potential buoyancy of the piping.

When a building is to undergo a change in use many factors can affect the plumbing required for the structure. You will need a permit for your work and this requires zoning approval for the work. In our example the present use is residential. It is being changed to commercial use. The fact that a dental office will exist in the building will require a variety of types of specialized plumbing that would not exist in a home. All of the existing plumbing may have to be removed and upgraded to meet current code requirements. Before you embark on plumbing for any change in use you should consult your local code enforcement office to define which elements of the existing plumbing can be kept in place and in use.

Piping that penetrates an exterior wall is required to be provided with adequate pipe protection. (UPC 305.3; 312.10). This protection is meant to keep the pipe from being crushed. The protection is generally provided by installing a sleeve that is at least two pipe diameters larger than the pipe being installed. Additionally, the sleeve must be installed in such a way to keep the opening watertight. (IPC 305.3; UPC 312.10).

The depth of frost penetration in earth varies from region to region. For example, the frost line in Maine is 4 feet. In a more southern state, the frost line could be 18 inches. Local plumbing codes define the depth of a frost line in their jurisdictions. Regardless of the depth of a frost line, plumbing pipes must be installed no less than 6 inches below the established frost line (IPC) or below 12 inches (UPC) as determined by the local plumbing code. (IPC 305.4; UPC 609.1). And, at no point is there to be less than 12 inches of ground cover over a buried pipe.

True - Mechanical joints are a recommended means of making connections between dissimilar types of materials. (IPC 705.16; UPC 705.10). They can also be used to join like materials.

An appeal of a code officer's decision must be based on the aspects of the code as they relate to the rejection that you are appealing. You will be required to specify why the appeal is necessary and warranted and this may involve reference to trade manuals but it is not required. In an appeal, you will essentially be arguing what is authorized under the code.

Ten feet is the maximum distance allowed between pipe supports for copper DWV piping that is installed in a vertical position. (IPC Table 308.5; UPC Table 313.3).

Foam pipe insulation installed on copper risers that will be stub-outs is a suitable means of protection from contact with concrete. It is also acceptable to sleeve the copper piping or tubing with a section of plastic piping. The goal is to prevent concrete from having direct contact with the copper piping. Any form of protection that is used should be secure and durable and should not be affected adversely from direct contact with concrete. (IPC 305.1; UPC 609.3).

Water is the test medium of choice. A 10-foot head of water is required for 15 minutes. It is common for modern DWV systems to be tested with air. The minimum test pressure is required to be 5 pounds per square inch (PSI). When there is a leak that cannot be found easily, smoke can be used to expose the leak location. Smoke is not used as a primary test method. (IPC 312.2, 312.3, 312.5; UPC 712.1).

False - The plumbing code requires that an air test on a DWV system be maintained at a minimum of 5 pounds PSI (UPC) or 10 pounds (IPC) for at least 15 minutes. (IPC 312.3; UPC 712.3). Air tests cannot be used on plastic piping. (IPC 312.3; UPC 609.4).

When underground plumbing is being tested there must be one riser that is at least ten feet above the main plumbing system. (IPC 312.3; UPC 712.2). This riser allows for a head of pressure to build over the entire system. This applies to a water test.

Any requirements necessary for the strength or proper operation of an existing or proposed plumbing system, or for the public safety, health and general welfare, not specifically covered by the plumbing code shall be determined by the code official. (IPC 104.2; UPC 103.1).

The maintenance of plumbing system is the responsibility of the owner. (IPC 102.3; UPC 102.3). The owner may authorize another party to be a responsible party for the property in which case that party is responsible for the maintenance of the plumbing system.

The final test of a vent and drainage system requires a visual test for compliance to the code. (IPC 111.2; UPC 105.2). In preparation of the final drain and vent test, the plumbing fixtures must be assembled, set and sealed to the walls and floors, connected to the water supply and drainage system (if required) and fixture traps filled with liquid. The final check of the drainage and vent system is up to the discretion of the code official.

All products and materials are to be certified in accordance with third party certification requirements. (IPC 303.4; UPC 301.2).

All water pipe in a parallel system when the hot and cold piping is bundled the hot water pipe must be insulated to stop the possible transfer of heat. (IPC 308.9; UPC 609.12.1). This can be done by insulating the hot water pipe with an insulation jacket or pipe separation fingers.

The rodding clearance on a cleanout for a 2" drain is 18". (IPC 708.1.10; UPC 707.9).

The maximum water temperature for head shampoo stations is 120°. (IPC 412.10; UPC 417.7).

Permits are authorized for 180 days and can be extended upon written request. (IPC 105.5.3; UPC 104.4.3).

An elevation reference point or critical level that determines the minimum height at which a backflow preventer or vacuum breaker is installed above the flood level rim of the fixture or receptor served by the device. The critical level is the elevation level below which there is a potential for backflow to occur.

Sump pumps are permitted at the base of the shaft if they are indirectly connected to the plumbing system and comply with section on oil separators. (IPC 301.6). They will have an oil interceptor or an approved alarm system.

The use of a sanitary tee receiving horizontal waste into the bull of a tee and the discharge down is acceptable. The top would be a vent. The use of a sanitary tee in the horizontal-to-horizontal position is prohibited because the tee is a short sweep fitting and blockages are likely to occur.

A journeyman plumber is not required to be under the direct supervision of a master plumber. It is a violation of the plumbing code for a journeyman plumber to work under a homeowner's permit and to receive payment, for such would require a master plumber operating as a business and obtaining the plumbing permit.

The minimum number of plumbing fixtures required for a single-family home is five. This includes a toilet, a lavatory, a bathing unit, a kitchen sink and a washing machine connection. (IPC Table 403.1; UPC Table 422.1). Additional fixtures can be added, such as dishwashers and hose bibs.

Multi-family buildings are required to be equipped with a laundry facility when the total number of rental units reaches 20 under the IPC and 12 under the UPC. (IPC Table 403.1; UPC Table 422.1). Additional laundry hook-ups are required for each additional interval of 20 or 12 units respectively. For example, a 60-unit building would be equipped with 3 laundry facilities under the IPC and 4 under the UPC.

For every 15 people housed in a daycare facility one toilet is required. (IPC Table 403.1). Depending on how a daycare is classified, it could be one toilet for up to 50 people. (UPC Table 422.1). If there were 45 people using the facility a total of three toilets would be needed. Local code requirements may require separate facilities for males and females. If this is the case, you must double the number of toilets so that there is a toilet for every 15 males and a toilet for every 15 females.

Five-hundred feet is the maximum allowable distance that employees can be required to walk in order to reach a restroom. (IPC 403.3.3; UPC 422.4).

Employees are not to ascend more than one set of steps to get to a restroom. (IPC 403.3.3; UPC 422.4.1). The plumbing facilities cannot be installed more than one story above the work area that employees will be moving from.

Since motel rooms are used by the public, and their restrooms will be used by the public, the bathrooms must be fitted with accessible plumbing facilities. (See Public Accommodation, ADA, Title 42, Section 12182; ICC A117.1; UPC 403.2).

Plumbers are prohibited from installing drinking fountains in public bathrooms. (IPC 410.5; UPC 415.4). The reason for this is to protect users of the restroom from germs and diseases that might be collected on a drinking fountain that is in a toilet room.

You will have to abide by both the plumbing and building codes when you are installing accessible plumbing fixtures. Requirements for fixture types, heights and placements will be identified in the plumbing code. The building code will dictate the access requirements, such as door widths. To design your plumbing system for accessible plumbing fixtures you will rely on both the building and plumbing codes and use them together in the overall design of your plumbing system.

The ICC A117.1 is the standard for accessible and usable buildings and facilities under both the IPC and UPC. (IPC 404.2; UPC 403.2).

False - The plumbing code requires that all hospitals be provided with at least two water services. But it allows for the use of a single water main. (IPC 609.2; UPC 1303.8). This means that one water main can be connected to two water services in order to provide water to a hospital.

Handicap toilets are required to have a minimum height of 17 inches. (ICC A-117.1, 604.4). The most common accessible toilets have a height of 18 inches. In extreme cases, you can obtain and install a toilet that enjoys a height of 20 inches. Eighteen inches is the most common height of a standard handicap toilet.

There is a type of toilet known as a siphon jet toilet. It is one of many types of toilets. Other types include: siphon vortex, siphon wash, reverse trap, and blowout toilets. All of these toilets are approved for use under the control of the plumbing code.

The minimum distance required in front of an accessible lavatory is 30 inches. (ICC A 117.1, 305.3). Accessible lavatories must also allow easy access by a person in a wheelchair. Typical designs for spacing in front of a lavatory include an area that is 30 inches by 30 inches.

Accessible lavatories are to be installed so that the top of the lavatory is never more than 34 inches above the finished floor beneath the lavatory. (ICC A117.1, 606.3). The measurement is made from the flood-level rim of the fixture to the finished floor.

Kitchen sinks installed for accessible use cannot be installed more than 34 inches from the finished floor. (ICC A117.1, 606.3). The measurement is made from the flood-level rim to the finished floor. The primary responsibility for counter height falls upon the building contractor and carpenters. Even so, if you install a sink in a counter that is not set within the regulatory guidelines of the building and plumbing codes you can count on having to remove that sink and reinstall it when the counter height is corrected.

Twenty-five inches is the maximum distance allowed between the front edge of a lavatory and the faucet installed on it when the fixture is to be rated as an accessible fixture. (ICC A117.1, 308.2.2).

Handicap faucets are required to be designed so that they will operate with a maximum operational force of five pounds. (ICC A117.1, 309.4). It is expected that users of these faucets may be limited in their strength and ability to move faucet handles. This is the reason for the light pressure requirements.

Crossbar handles are not allowed for use in conjunction with accessible faucets. (ICC A117.1, 404.4.6). The types of handles that are allowed include: push-button handles, sensor-units, blade handles, wing handles and single handles. The reason for this is that finger dexterity is not a requirement for operating the handles.

Grab bars are required to be installed for all bathtubs that are installed for accessible use. (ICC A117.1, 607.4). These bars are required to have a minimum diameter of 1.25 inches. The diameter cannot exceed 2 inches. The bars are required to be at least 24 inches in length and installed horizontally.

A minimum length of five feet is required for hoses installed on personal shower units in handicap bathing units. (ICC A117.1, 607.6). The hose must be long enough to allow bathers to use it from seats in bathing units and from wheelchairs.

True - Public restroom facilities must have accessible travel routes that do not go through kitchens, storage rooms or closets. (IPC 403.3.1; UPC 422.4.1).

An accessible shower that contains a seat must be provided with a seat that is not more than 16 inches in length from the seat wall. (ICC A117.1, 610.3.1). Permanent seats have to be mounted along a sidewall of the shower and run the full length of the shower.

There is a height requirement to be observed in an accessible use situation. The seat is to have a height that is not less than 17 inches and not more than 19 inches from the finished floor. (ICC A117.1, 610.2).

The code citation for Drinking Fountains, Operable Parts, ICC A117.1 602.3.1, refers the plumber to section 309.3 for the height of the operable parts. This sections then refers the plumber to section 308, where the reach ranges are set forth.

Bidets are required to have a minimum of 30 inches of clear space for a suitable installation. This requires a minimum of 15 inches of clearance on both sides of the bidet from the center of the drain opening. (IPC 405.3.1; UPC 402.5).

Plumbing fixtures are required to be installed level and with good workmanship. (IPC 405.3; UPC 309.4, 402.5). Code officers are allowed to reject plumbing work that is not done with good workmanship principles. When speaking in terms of being level, this refers to both a left-to-right position and a front-to-back position.

Closet bolts should be constructed of brass. This is the industry standard. The bolts that hold a toilet to a flange or floor are required to be resistant to corrosive action. (IPC 405.4; UPC 402.6). When they are not, they can weaken and allow a toilet to move over time and with usage. Brass lag bolts should be used to secure toilets to floors when no closet flange is installed.

All shower doors are required to allow for a minimum unobstructed opening of ingress and egress of not less than 22 inches. (IPC 421.4.2; UPC 408.6).

True - Three-hundred feet is the maximum travel distance allowed for the public to reach a unisex toilet facility. (IPC 403.3.4; UPC 422.4). The 300 feet is measured from the entry of any store in the shopping mall to the toilet facility. Unisex restrooms are not allowed to be located more than one story above or below a separate-sex restroom. A five-hundred feet maximum is the distance for structures other than shopping malls or centers. (IPC 403.3.3; UPC 422.4).

The reason for a pressure-balanced valve is to protect people from unexpected changes in water temperatures. It is bad enough when a warm shower shifts to cold water as some other fixture is used in the system. But it can be far worse if extreme hot water is expelled quickly and without warning. Infants and elderly people may not be able to move quickly enough to avoid pain and possible skin damage from unchecked hot water. Temperature actuated flow reduction valves are not a suitable replacement for a balanced pressure valve.

Bathtubs are required to have a waste outlet with a stopper. (IPC 407.2; UPC 409.2). Many types of devices are allowed to function as a stopper. They include all of the following: plunger stoppers, rubber stoppers, lift-and-turn stoppers, push-pull stoppers and snap-down-pop-up stoppers.

A tub waste and overflow that is installed with the use of slip nuts and washers requires an access panel. (IPC 405.9; UPC 402.10). This is necessary for any required service to the tub waste. The use of solid, permanent connections for tub wastes eliminates the need for access panels. Solvent-weld joints and soldered joints are examples of such connections.

Dishwashers are required to discharge their waste through an air gap. (IPC 802.1, 802.3; UPC 801.2, 807.1). The reason for this is to eliminate the possibility of back siphonage. One alternative is to install a backflow preventer on the drainage line, but this is extremely rare. Air gaps are normally installed on the deck of a kitchen sink, but they can be installed on a kitchen counter.

The drain from a washing machine is required to discharge into an indirect waste receptor. (IPC 406.2; UPC 804.1, 1001.2).

Garbage disposers are required to discharge into drains that have a minimum diameter 1.5 inches. (IPC 416.2; UPC Table 702.1). All drainage connections for garbage disposers are required to be solid connections. These fixtures require their waste to be trapped. It is acceptable to connect the waste from garbage disposers to the waste system of a kitchen sink. When this is the case, the trap for the kitchen sink also serves as the trap for the garbage disposer.

False - You cannot install grab bars below faucets in bathing units. Controls must be installed between the flood rim of the tub and the grab bar. (ICC A117.1 607.5). The specifications for all required grab bars, their minimum dimensions and their placement can be found in the plumbing code.

The minimum allowable diameter for a drain pipe that receives the waste from a floor drain is two inches. (IPC Table 710.1; UPC 717.1). Floor drains are to be trapped and vented. Each floor drain is required to be fitted with a removable strainer. The strainers are required to be readily accessible.

A 2" waste outlet for a shower meets the minimum requirements of the IPC (1.5") and the UPC (2"). (IPC 421.3; UPC 408.5). Removable strainers are required to cover the shower drain within the shower base. At no time can the diameter of the drain be reduced in its run towards a building sewer.

Anti-siphon construction is a requirement for all ballcock assemblies that are installed in toilets for residential use. (IPC 415.3.1; UPC 413.3). Older style ballcocks remain on the open market but they are not approved for use. Even if you are doing service and repair work, you must install only anti-siphon devices.

By the code, a minimum diameter of a drain pipe for commercial garbage disposers is 1.5 inches for the IPC and 2 inches for the UPC. (IPC 416.3; UPC Table 702.1). Many plumbers will use no smaller than 2 inches. They require their own drainage piping and trap. Do not confuse the code regulations for residential garbage disposers with the requirement for commercial garbage disposers. A cold-water source must be available to the disposer. The water source can be of an automatic type. Commercial garbage disposals are not allowed to be connected to grease interceptors.

False - It is common for grease traps to be installed in commercial kitchens. Do not let this fool you. Commercial garbage disposals must not be connected to grease interceptors. (IPC 1003.3.2; UPC 1014.13).

Backflow protection must be installed on the water supply lines for garbage can washers. (IPC 417; UPC 603.5.19). An air gap is the right choice of the answers given. Due to the nature of the use of these devices the risk of backflow into a potable water source is not acceptable. You must ensure that the water supply will not be at risk of siphoning dirty water into the potable water distribution system. A vacuum breaker could also be used.

A urinal that uses water is required to be served by a single flush valve. (IPC 415.1; UPC 413.1). The valve must be of an approved type and may be handle or sensor operated.

Bedpan washers are also known as clinical sinks. It is common for the flush-valve piping to water closets to contain piping that is designed to be activated as a bedpan washer. This reduces the need for a separate fixture in healthcare facilities.

When a plumbing device is required to be readily accessible it must be able to be worked on without having to move or remove anything. For example, a pressure-reducing valve that is installed on a water distribution pipe near the connection to a water service in an unfinished basement where the valve can be seen and touched is installed in a readily accessible way.

When a backflow preventer is installed to protect a fixture the backflow device is required to be installed a minimum of six inches above the flood-level rim of the fixture. (IPC 608.16.4; UPC 603.5.1). This can become confusing when working with showers. Handheld shower devices that have backflow preventers installed must have them installed a minimum of six inches above the highest point to which the handheld shower can be raised.

False - Drinking fountains are not allowed to be installed in rooms where toilet facilities exist. (IPC 410.5; UPC 415.4). This is for sanitation purposes. While it is true that toilets require a minimum of 15 inches from the center of the toilet drain to the closest fixture is true. But, the fact that drinking fountains are not allowed to be installed in toilet rooms makes the statement false.

Plumbing fixtures must be installed in such a way that they offer easy access for cleaning and repair regarding both the fixture and the area around the fixture. All fixtures must be caulked to prevent germ and mold growth. All ADA fixtures must be installed for accessibility height for use. The code does not require the use of ridged piping on all connections.

Public drinking fountains cannot be more than one story above or below the tenant space and must be on an accessible route. (IPC 403.5). Based on the number of stories in this scenario, at least 2 public fountains would be needed. Under the IPC and UPC, additional fountains may be needed based on the size of the tenant space and number of people using the space. (IPC Table 403.1; UPC Table 422.1).

When a building has a building load of 15 or less (IPC) or 30 or less (UPC), drinking fountains are not required. (IPC 410.2; UPC 415.2)