OBC Plumbing All Buildings cheat sheet

The plumbing code applies to all new construction, additions, alterations, and repairs of plumbing systems in all buildings, including residential, commercial, and institutional occupancies.

Permits are required before installing, altering, or repairing any plumbing system, except for minor repairs such as clearing stoppages or replacing faucet washers.

Plans and specifications must be submitted to the authority having jurisdiction (AHJ) for review before a permit is issued for any plumbing system.

Materials must be listed and labeled by an approved agency, and installed in accordance with the manufacturer's installation instructions.

All plumbing work must be performed by a licensed plumber or under the direct supervision of one, unless exempted by the AHJ.

The AHJ has the authority to inspect, approve, or reject any plumbing work and may issue stop-work orders for noncompliance.

Provisions must be made for structural support, protection from freezing, and access for maintenance and inspection of all plumbing components.

Existing plumbing systems that are altered must comply with the current code for the altered portion and must not create a hazard or reduce the performance of the existing system.

The AHJ is the organization, office, or individual responsible for enforcing the code and approving materials, equipment, and methods.

A plumbing fixture is a receptacle that receives water or waste and discharges it to the drainage system, such as a sink, water closet, or bathtub.

A trap is a fitting that retains a water seal to prevent the passage of sewer gas into a building.

The drainage system includes all piping, fixtures, and fittings that convey sewage or other waste to the building sewer.

The venting system provides a means for air to enter and exit the drainage system to equalize pressure and protect trap seals.

The water supply system includes all piping, fixtures, and fittings that convey water from the source to the point of use.

Administrative provisions cover permit applications, fees, inspections, and the appeals process for code interpretations.

A building sewer is the pipe that connects the building drainage system to the public sewer or private disposal system.

Each fixture must be constructed of approved materials that are durable, nonabsorbent, and resistant to corrosion and chemicals.

Fixtures must have smooth, impervious surfaces that are easily cleanable and must not have concealed fouling surfaces.

Water closets must be of the flushometer or gravity type and must have a water consumption rate not exceeding 1.6 gallons per flush.

Urinals must have a water consumption rate not exceeding 1.0 gallon per flush, and waterless urinals are permitted where approved.

Shower compartments must have a minimum interior area of 900 square inches and a minimum dimension of 30 inches.

Bathtubs and showers must have a slip-resistant surface or be provided with a slip-resistant mat or strips.

Drinking fountains must be provided with a minimum of one fountain per 100 occupants and must be accessible to persons with disabilities.

Fixtures must be installed with clearances that allow for cleaning, maintenance, and use, and must be securely fastened to the structure.

Fixture fittings must be of an approved type and must be installed in accordance with the manufacturer's instructions.

Shower valves must be of the pressure-balancing or thermostatic mixing type to prevent scalding.

Bathtub and shower valves must be limited to a maximum water temperature of 120°F at the outlet.

Faucets must have a maximum flow rate of 2.2 gallons per minute at 60 psi, and showerheads a maximum of 2.5 gallons per minute.

Fixture supply pipes must be sized to provide adequate flow and pressure to each fixture at peak demand.

Water closets must have a flush valve or flushometer that is approved and that provides a complete flush.

Fixture drains must be provided with a trap and must be sized to carry the fixture's discharge load.

Backflow prevention devices must be installed on all connections to the potable water system where a cross-connection may occur.

Drainage piping must be sized based on the total drainage fixture units (dfu) connected to the system.

The minimum slope for horizontal drainage pipes is 1/4 inch per foot for pipes 2.5 inches and smaller, and 1/8 inch per foot for larger pipes.

Drainage pipes must be installed with a uniform slope and must not have sags or traps that could collect solids.

Changes in direction must be made with approved fittings; sanitary tees are not permitted for horizontal-to-horizontal connections.

Drainage systems must be provided with cleanouts at intervals not exceeding 100 feet and at the base of each stack.

The building drain must be connected to the building sewer with a watertight joint and must be protected from backflow.

Drainage pipes must not be installed under a building unless they are approved for such use and are provided with cleanouts.

Sumps and pumps must be provided where gravity drainage is not possible, and must be sized to handle the expected flow.

Each plumbing fixture, except those with integral traps, must be provided with a trap that retains a water seal of at least 2 inches and not more than 4 inches.

Traps must be of a self-cleaning design and must be installed level to maintain the water seal.

A trap may serve only one fixture, except where a single trap serves a set of fixtures in a battery.

Cleanouts must be provided at the base of each vertical stack, at intervals not exceeding 100 feet in horizontal drains, and at changes in direction exceeding 45 degrees.

Cleanouts must be accessible and must have a removable plug that is gas-tight and watertight.

Trap arms must be sized according to the fixture drain and must not exceed the maximum length specified in the code.

Traps must be protected from freezing and from backflow by an approved means.

Cleanouts must be installed at the junction of the building drain and building sewer and at the upstream end of any horizontal drain.

Each trap must be protected by a vent that is connected to the vent stack or to a common vent.

The vent system must be sized based on the total venting load and the developed length of the vent pipe.

A vent pipe must rise vertically at least 6 inches above the fixture it serves before any horizontal offset.

Common vents may serve two fixtures on the same floor when the fixtures are within the specified distance and the vent is sized accordingly.

A wet vent may serve a maximum of two fixtures and must be sized to carry both the waste and the vent load.

Vent terminals must extend at least 6 inches above the roof and must be located at least 10 feet from any air intake or operable window.

The vent system must be provided with a means of preventing the accumulation of condensate and must be protected from freezing.

Air admittance valves may be used where approved and must be installed in accordance with the manufacturer's instructions and the code.

Water supply piping must be sized to provide the required flow and pressure to each fixture at peak demand.

The minimum residual pressure at a fixture is 8 psi for flushometer valves and 15 psi for other fixtures.

The water supply system must be protected from contamination by backflow prevention devices and air gaps.

Water supply pipes must be installed with a minimum slope of 1/8 inch per foot to allow for drainage and air removal.

Water supply pipes must be protected from freezing and from physical damage.

The water distribution system must be provided with valves to isolate sections for repair and maintenance.

Water supply pipes must be tested at a pressure of at least 50 psi and must maintain that pressure for at least 15 minutes.

Water supply systems must be designed to avoid excessive velocities that can cause noise and erosion of pipes.

Special plumbing systems include those for laboratories, hospitals, and other occupancies with unique plumbing needs.

Acid waste systems must be provided with acid-resistant piping and must be neutralized before discharge to the sewer.

Grease interceptors must be provided for commercial kitchens and must be sized according to the fixture load and the code.

Sand and oil interceptors must be provided for garages and other areas where oil and sand may enter the drainage system.

Special systems must be designed by a licensed professional engineer and approved by the AHJ.

Medical gas systems must comply with NFPA 99 and must be installed by qualified personnel.

Rainwater harvesting systems must be designed to prevent contamination of the potable water system.

Swimming pool and spa plumbing must comply with the code and must be provided with backflow prevention and filtration.

Interceptors must be provided to prevent the discharge of harmful substances into the drainage system.

Grease interceptors must be installed outdoors or in a vented location and must have a minimum capacity of 1,000 gallons for certain applications.

Oil interceptors must be sized to handle the expected flow and must be provided with a means of removing the oil.

Sand interceptors must be provided with a means of removing the sand and must be sized to handle the expected flow.

Interceptors must be provided with cleanouts and must be accessible for maintenance.

Special wastes such as chemicals, acids, and alkalis must be treated before discharge to the sewer.

Interceptors must be vented in accordance with the venting requirements of the code.

The discharge from interceptors must be approved by the AHJ and must not create a hazard or nuisance.

The plumbing system must be designed and installed to prevent contamination of the potable water supply.

Cross-connections must be eliminated or protected by an approved backflow prevention device.

The potable water system must be protected from contamination by nonpotable water systems and by backflow.

All plumbing fixtures must be installed with adequate ventilation to prevent the accumulation of sewer gas.

Plumbing systems must be designed to prevent the spread of disease and to maintain sanitary conditions.

Water heaters must be provided with a temperature and pressure relief valve and a discharge pipe.

The water supply must be tested for bacteriological quality and must meet the standards of the health authority.

Plumbing systems must be maintained in a sanitary condition and must be kept free of leaks and stoppages.

Storm drainage systems must be designed to handle the maximum expected rainfall for the area.

Roof drains must be sized based on the roof area and the rainfall intensity, using the code's tables.

Storm drainage pipes must be sized to carry the peak flow and must be installed with a minimum slope of 1/8 inch per foot.

Storm drainage systems must be separate from the sanitary drainage system unless combined systems are approved.

Storm drainage systems must be provided with cleanouts and must be protected from freezing.

Roof drains must be provided with strainers and must be installed at the low points of the roof.

Storm drainage systems must be tested for watertightness before being covered.

The discharge from storm drainage systems must be to an approved location and must not create a hazard or nuisance.

Plumbing facilities must be accessible to persons with disabilities in accordance with the applicable accessibility standards.

Water closets must be provided with grab bars and must have a clear floor space of at least 60 inches wide and 56 inches deep.

Lavatories must be installed with a clear space of at least 30 inches wide and 48 inches deep, and must have a knee clearance of at least 27 inches high.

Showers must be provided with a seat, grab bars, and a hand-held showerhead, and must have a clear floor space of at least 30 inches by 60 inches.

Bathtubs must be provided with grab bars and must have a clear floor space of at least 30 inches by 60 inches.

Drinking fountains must be provided with a clear floor space of at least 30 inches by 48 inches and must have a spout height of no more than 36 inches.

Pipes and fixtures must be insulated or protected to prevent contact with persons with disabilities.

Accessible fixtures must be provided with controls that are operable with one hand and that do not require tight grasping or twisting.

The AHJ must inspect all plumbing work before it is covered or concealed.

Drainage systems must be tested with water or air at a pressure of at least 5 psi for at least 15 minutes.

Water supply systems must be tested at a pressure of at least 50 psi for at least 15 minutes.

The tests must be witnessed by the AHJ or an approved inspector.

A certificate of approval must be issued by the AHJ after successful inspection and testing.

Plumbing systems must be maintained in accordance with the code and the manufacturer's instructions.

The AHJ may require additional tests or inspections for special systems or where conditions warrant.

Records of inspections and tests must be maintained and made available to the AHJ upon request.