NM Journeyman Plumber cheat sheet

Plumbing system includes water supply and distribution pipes, fixtures and fittings, drainage and venting, and water-heating appliances; it stops at the connection to the public sewer or private disposal system.

Potable water is water free from impurities in amounts sufficient to cause disease or harmful physiological effects, meeting the primary and secondary drinking-water standards.

A fixture is a receptacle or device that receives water or waste and discharges it to the drainage system; a fixture fitting is a device that controls or directs water flow to or from a fixture.

Waste is any liquid or solid discharge from a fixture, appliance, or appurtenance; sewage contains animal or vegetable matter; storm water is rainfall or surface runoff.

Drain is a pipe carrying waste, sewage, or clear-water waste; a soil pipe carries sewage containing fecal matter; a waste pipe carries waste free of fecal matter.

Vent is a pipe providing a flow of air to or from a drainage system to protect trap seals; a stack is a vertical pipe with flow under gravity; a riser is a vertical supply pipe.

Backflow is the reversal of normal flow direction; backsiphonage is backflow caused by negative pressure in the supply line.

A cross-connection is any actual or potential connection between the potable supply and any source of contamination or pollution.

Developed length is the distance along the centerline of a pipe and its fittings, measured from the face of one fitting to the face of the next.

Slope in percent = (rise ÷ run) × 100; slope in inches per foot = rise in inches × 12 ÷ run in inches. A 1/4 inch per foot slope equals 2.08 percent.

Fall = slope × run: at 1/4 inch per foot, a 40-foot run drops 10 inches (0.25 × 40).

Fixture units (FU) are the weighted drainage or supply load of a fixture; 1 FU of drainage load equals 1 cubic foot per minute (7.5 gpm) of flow.

Drainage pipe capacity is sized from total FU and slope; steeper slope permits smaller pipe for the same FU load, and building drains below 1/8 inch per foot are not permitted.

A horizontal drain must be sized so that the flow depth does not exceed one-half the pipe diameter at the design slope.

Building water supply is sized from total supply FU converted to gpm, then adjusted for flush-tank versus flushometer fixtures and for pressure available.

Pressure in psi = head in feet × 0.433 (water); conversely, head in feet = psi × 2.31.

Static pressure loss from elevation is 0.433 psi per foot of height; a 30-foot rise costs about 13 psi of static pressure.

Volume of a pipe in gallons = 0.0408 × inside diameter squared (inches) × length (feet); a 1-inch pipe holds about 0.041 gallons per foot.

Water closets are classified as floor-mounted or wall-hung and as gravity, flushometer-tank, or flushometer-valve types; water consumption is limited to 1.6 gallons per flush for tank type and 1.28 gpf for high-efficiency closets.

Urinals are limited to 1.0 gallon per flush; non-water-supplied urinals are permitted where the code and the authority having jurisdiction allow.

Lavatory faucets are limited to 2.2 gpm at 60 psi, or 1.5 gpm for high-efficiency models; kitchen faucets are limited to 2.2 gpm.

Showerheads are limited to 2.5 gpm at 80 psi; multiple showerheads in one shower are limited to a combined 2.5 gpm in most model codes.

Blending valves for public lavatories must be thermostatic or temperature-limiting to control scald; shower and tub-shower valves must be pressure-balancing or thermostatic mixing valves.

Fixture clearances: water closets require at least 15 inches from the centerline to a side wall or partition and at least 21 inches of clear space in front.

Air gap is the unobstructed vertical distance through free atmosphere between the outlet of the waste pipe and the flood-level rim of the receptacle; it is the only backflow prevention that is not a mechanical device.

A backflow preventer with intermediate atmospheric vent is required for boiler feed connections and similar low-hazard connections; a reduced-pressure principle assembly is required for high-hazard conditions.

Fixture fittings must be listed and must not be installed on a fixture unless the fixture is designed for that fitting; slip-joint and exposed connections must be accessible.

Minimum service pipe size is 3/4 inch for a single-family dwelling; building supply pipe is sized from the total demand in gpm and the available pressure after elevation loss.

Minimum residual pressure is 8 psi at a flushometer valve and 8 psi at the highest fixture served; many codes require 15 psi at the building supply under peak demand.

A water service must be protected against backflow; where a meter is installed, a check valve or backflow preventer is required at the service.

Water distribution pipes must be protected from freezing; in New Mexico, bury depth must be below the local frost line, typically 12 to 18 inches depending on elevation and region.

A main water shutoff valve must be installed inside the building near the point of entry and must be accessible; a full-port valve is required for the main.

Thermal expansion control is required where a backflow preventer or check valve creates a closed system on the domestic supply.

Pressure-reducing valves are required where the static pressure exceeds 80 psi; a thermal expansion tank or relief valve must be installed downstream.

Water supply piping must be supported at intervals not exceeding 32 inches for horizontal copper and 10 feet for horizontal PEX, with supports within 1 foot of each fitting.

A water hammer arrestor is required at the end of long runs serving quick-closing valves, such as flushometer toilets and washing machine boxes.

Every fixture must be trapped and each trap must be vented; a trap may not be double-trapped, and a trap arm may not change direction more than once without a cleanout.

The trap arm length is limited by the trap arm diameter: 1-1/4 inch = 5 feet, 1-1/2 inch = 6 feet, 2 inch = 8 feet, 3 inch = 12 feet, 4 inch = 16 feet.

A vent stack must extend at least 6 inches above the roof or 12 inches above the roof surface where snow can accumulate, and must be at least 3 feet from any window or air intake.

A horizontal drain must be supported at intervals not exceeding 4 feet for pipe up to 2 inches, 5 feet for 3 to 4 inches, and 6 feet for larger pipe.

A building drain must be at least 2 inches in diameter; a building sewer must be at least 3 inches; a building drain serving a water closet must be at least 3 inches.

Cleanouts are required at the base of each soil stack, at the building drain and sewer junction, at each change of direction greater than 45 degrees, and at intervals not exceeding 100 feet.

A vent must be at least 1-1/4 inch for a 1-1/4 inch trap, 1-1/2 inch for a 1-1/2 inch trap, and 2 inch for a 2 inch trap; the vent must be at least one-half the drain diameter for larger drains.

A wet vent may serve a maximum of 2 fixtures, and a wet vented fixture must be on the same floor as the wet-vented branch and must connect to a horizontal branch.

A combination waste and vent system is permitted only for floor drains, sinks, and similar fixtures, and the pipe must be sized at least 2 inches larger than a conventional drain.

The building drain must be 12 inches below the basement floor or 18 inches below the lowest fixture, whichever is greater, to allow drainage by gravity.

A trap seal must be at least 2 inches and not more than 4 inches deep; a trap shall not be more than 4 inches deep unless specifically listed.

A trap must be self-cleaning and must not be subject to siphonage; the trap arm must be level or slope downward at no more than 1/4 inch per foot.

A grease interceptor is required for commercial food-service establishments; it must be sized by the fixture-unit method or by the grease-producing fixture capacity and must be accessible for cleaning.

A grease interceptor must be installed on the waste line from the fixtures, with a flow-control fitting, and must be vented to prevent air lock.

A sand and oil interceptor is required for automotive repair, car washes, and similar facilities; it must be sized to the fixture discharge and have a removable cover.

A clothes-washer standpipe must be at least 2 inches in diameter, at least 18 inches and not more than 42 inches above the floor, and must be trapped.

A dishwashing machine waste must discharge through an air gap or air-break fitting to a trapped receptor; a direct connection is not permitted.

A food-waste grinder must be connected to a drain of at least 2 inches and must be trapped; the trap must be accessible.

Special waste such as acid waste, chemical waste, and radioactive waste must be conveyed in approved corrosion-resistant piping to a neutralization or treatment system before entering the building sewer.

Storm drainage must be separate from the sanitary drainage system; storm water may not discharge into the sanitary sewer except where combined systems are approved.

Roof drains are sized by the roof area in square feet and the design rainfall rate in inches per hour; the rainfall rate for New Mexico is generally 2 to 4 inches per hour depending on location.

The flow from a roof drain in gpm = roof area (square feet) × rainfall rate (inches per hour) × 0.0104.

A secondary roof drain or overflow scupper is required where the primary roof drain could be blocked; the secondary drain must discharge at a visible location.

Subsoil drains must be installed around foundations and under basements and must discharge to a storm drain, a sump, or a dry well; they may not connect to the sanitary sewer.

Subsoil drain pipe must be at least 4 inches in diameter, with perforations facing down, and must be surrounded by washed gravel or crushed stone.

A subsoil drain must be protected by a backwater valve where the discharge point is subject to backflow.

Storm drain leaders must be supported at intervals not exceeding 10 feet and must be protected against freezing where they pass through heated space.

A storm drainage system must be provided with a cleanout at the base of each leader and at each change of direction greater than 45 degrees.

A temperature and pressure relief valve must be installed on every water heater; the valve must be listed, set at 210 degrees F and 150 psi, and must not be valved off.

The relief valve discharge pipe must be full size, terminate within 6 inches of the floor or outside, and must not be trapped or reduced.

A water heater must be installed on a stand at least 18 inches above the floor in a garage where the ignition source is within 18 inches of the floor.

A water heater must be provided with a drain pan where leakage could cause damage; the pan must be at least 1-1/2 inches deep and must drain to an approved location.

A thermal expansion tank is required where a check valve or backflow preventer creates a closed system on the domestic supply.

A water heater must be seismically restrained in seismic zones; New Mexico has areas of moderate to high seismic risk and local rules may require strapping.

A recirculation system may be required for hot water to distant fixtures; hot water must reach the fixture within a reasonable time, and the pipe must be insulated.

A water heater must be vented to the outdoors; the vent must be sized to the appliance input and must not be reduced or connected to a smaller vent.

A tankless water heater must be sized to the peak demand in gpm and the temperature rise; the flow rate at the design temperature rise must meet the fixture demand.

Gas pipe sizing uses the longest-run method; the total demand of all appliances is used with the longest length from the meter to the farthest appliance.

Gas pipe must be sized from the appliance input in Btu per hour and the specific gravity of the gas; natural gas is about 0.60 specific gravity and propane is about 1.5.

Gas piping must be supported at intervals not exceeding 6 feet and must be protected from corrosion and physical damage.

A gas shutoff valve must be installed within 6 feet of each appliance and must be accessible; a union must be installed downstream of the valve.

A sediment trap must be installed on the appliance connector, with the trap leg extending downward at least 3 inches below the gas inlet.

Gas piping must be tested at 1-1/2 times the working pressure, but not less than 3 psi for a 10-minute test on low-pressure systems; the test medium is air or inert gas.

A gas appliance must be connected to a vent with a draft hood or draft diverter where the appliance is not a direct-vent type; the vent must terminate above the roof.

A gas-fired appliance must have combustion air from an outdoor source or from a space of sufficient volume; the minimum volume is 50 cubic feet per 1,000 Btu per hour of input.

A gas appliance must not be installed in a bedroom or bathroom unless it is a direct-vent or sealed-combustion type.

Combustion air required for a confined space is 50 cubic feet per 1,000 Btu per hour of total input; a space is confined if its volume is less than 50 cubic feet per 1,000 Btu.

Two permanent openings are required for a confined space, one within 12 inches of the ceiling and one within 12 inches of the floor; each opening must have a free area of 1 square inch per 1,000 Btu per hour.

When combustion air is taken from outdoors through horizontal ducts, each opening must have 1 square inch of free area per 2,000 Btu per hour.

A draft hood must be installed on an appliance where required and must not be modified; a blocked flue must be detected by a spill switch or by a carbon monoxide alarm.

A carbon monoxide alarm must be installed in the vicinity of the bedrooms and on each floor of a dwelling with a fuel-burning appliance.

A gas appliance must have a clearance to combustibles as listed on the appliance label; a reduced clearance requires a listed clearance-reduction shield.

A plumbing vent must terminate at least 3 feet from a window, door, or air intake and at least 10 feet from a mechanical air intake or a property line.

A backflow preventer must be tested annually where required; test reports must be kept and made available to the authority having jurisdiction.

Confined-space entry requires atmospheric testing for oxygen, flammable gas, and toxic gas before entry; a permit and attendant are required.

New Mexico adopts the Uniform Plumbing Code as the state plumbing code, with state amendments administered by the Construction Industries Division (CID) of the Regulation and Licensing Department.

A plumbing permit is required before installing, altering, or repairing a plumbing system; permits are issued by the local jurisdiction or by CID where no local program exists.

A permit is not required for minor repairs such as replacing a faucet, a toilet, or a water heater of the same size and type, but local rules may still require notification.

Plumbing work must be performed by a licensed journeyman plumber under a licensed plumbing contractor; an apprentice must work under direct supervision.

A journeyman plumber license requires passing the journeyman examination and completing the required hours of supervised experience; the license must be renewed and continuing education may be required.

Inspections are required at rough-in, at the installation of the water heater, and at final; the rough-in inspection must occur before the pipe is covered.

A water supply system must be tested at 100 psi for at least 15 minutes or at the working pressure for 30 minutes, whichever is greater, before it is covered.

A drainage system must be tested with water or air; a water test requires filling the system to the highest point and holding for at least 15 minutes.

Plans and specifications must be submitted for review for commercial projects; the authority having jurisdiction may require engineering calculations for sizing.

The New Mexico Plumbing Code is based on the Uniform Plumbing Code and is enforced by the Construction Industries Division; local jurisdictions may adopt the same code with amendments.

A permit application must include the scope of work, the fixtures and appliances to be installed, and the name of the licensed contractor.

A permit must be posted on the job site and must be available for inspection; work may not proceed beyond the stage inspected without approval.

The authority having jurisdiction may require a final inspection before a certificate of occupancy is issued; a failed inspection requires a correction and a reinspection.

A plumbing contractor must maintain a surety bond and insurance as required by the state; the license number must appear on contracts and permits.

A change order that alters the scope of work requires an amended permit and may require additional fees.

A stop-work order may be issued for work without a permit or for work that is unsafe; the order must be resolved before work resumes.

A variance may be requested from the authority having jurisdiction where strict compliance with the code is impractical; the request must be in writing and must show equivalent protection.

Records of inspections and permits must be retained by the jurisdiction; a contractor must keep records of tests and inspections for the project.

A plumbing permit is required for new construction, additions, and alterations; a permit is not required for minor repairs that do not change the piping or fixtures.

A journeyman plumber may supervise apprentices and may perform plumbing work under a licensed contractor; a master plumber may hold the contractor license.

A plumbing inspection must be requested at least one business day before the inspection; the work must be complete and accessible.

A rough-in inspection must occur after the piping is installed and before it is covered; a final inspection must occur after fixtures are set and tested.

A water heater installation requires a permit in most jurisdictions and must be inspected for the relief valve, venting, and combustion air.

A gas piping installation requires a separate gas permit and a pressure test; the test must be witnessed by the inspector.

A plumbing system must be protected from freezing; the authority having jurisdiction may require insulation or heat tracing for exposed piping.

A backflow prevention assembly must be tested by a certified tester and the test report filed with the water purveyor and the authority having jurisdiction.

A plumbing code official may approve alternative materials and methods where the proposed design is equivalent in safety and performance to the code requirements.

The New Mexico Plumbing Code requires a plumbing contractor to be licensed by the state and to carry the license number on all permits and contracts.

A permit is required before any plumbing work begins; work started without a permit is subject to a double fee and possible stop-work order.

A plumbing inspector may enter a premises at reasonable times to inspect; the owner or occupant must provide access.

A final inspection must verify that fixtures are set, traps are installed, vents terminate properly, and the water and drainage systems have been tested.

A water heater must be inspected for the temperature and pressure relief valve, the discharge pipe, the vent, and combustion air before it is placed in service.

A gas appliance must be inspected for the sediment trap, the shutoff valve, the connector, and the vent before it is placed in service.

A plumbing system serving a commercial kitchen must be inspected for the grease interceptor, the air gap at the dish machine, and the indirect waste connections.

A plumbing plan review may require hydraulic calculations for water supply and drainage sizing on commercial projects.

A certificate of occupancy may not be issued until the plumbing final inspection is approved and all fees are paid.

The New Mexico Plumbing Code is administered by the Construction Industries Division; the code is the Uniform Plumbing Code as amended by the state.

A plumbing permit must be obtained from the local jurisdiction or from CID where no local program exists; the permit must be posted on the job site.

A journeyman plumber license requires a passing score on the journeyman examination and the required hours of supervised experience; the license must be renewed.

A plumbing contractor must be licensed and bonded; the contractor is responsible for the work of employees and subcontractors.

A rough-in inspection must be requested after the piping is installed and before it is covered; the inspector must approve the work before covering.

A water supply test must be at least 100 psi for 15 minutes or at working pressure for 30 minutes; a drainage test must be a water or air test held for at least 15 minutes.

A gas piping test must be at 1-1/2 times the working pressure but not less than 3 psi for 10 minutes; the test must be witnessed by the inspector.

A backflow prevention assembly must be tested annually by a certified tester; the test report must be filed with the water purveyor.

A stop-work order may be issued for unpermitted or unsafe work; work may not resume until the order is resolved and the permit is obtained.

A plumbing permit is required for new construction, remodeling, and replacement of piping or fixtures; minor repairs such as a faucet washer are exempt.

A plumbing contractor must be licensed by the state and must include the license number on the permit application and the contract.

A journeyman plumber may perform plumbing work under a licensed contractor and may supervise apprentices; a master plumber may qualify the contractor license.

A rough-in inspection must be requested before piping is covered; a final inspection must be requested after fixtures are set and the system is tested.

A water heater installation requires a permit and an inspection of the relief valve, the vent, and combustion air.

A gas piping installation requires a separate permit and a pressure test witnessed by the inspector.

A backflow prevention assembly must be tested by a certified tester and the report filed with the water purveyor.

A plumbing code official may approve alternative materials and methods where the design is equivalent in safety and performance.

A certificate of occupancy may not be issued until the plumbing final inspection is approved and all fees are paid.

The New Mexico Plumbing Code is the Uniform Plumbing Code as amended by the state and enforced by the Construction Industries Division.

A permit must be obtained before work begins; work without a permit is subject to a double fee and a stop-work order.

A plumbing contractor must be licensed and bonded; the license number must appear on permits and contracts.

A journeyman plumber license requires a passing examination and the required supervised experience; the license must be renewed.

A rough-in inspection must occur after piping is installed and before it is covered; a final inspection must occur after fixtures are set.

A water supply test must be at least 100 psi for 15 minutes or at working pressure for 30 minutes; a drainage test must be held for at least 15 minutes.

A gas piping test must be at 1-1/2 times the working pressure but not less than 3 psi for 10 minutes.

A backflow prevention assembly must be tested annually by a certified tester and the report filed with the water purveyor.

A certificate of occupancy may not be issued until the plumbing final inspection is approved and all fees are paid.

The New Mexico Plumbing Code is based on the Uniform Plumbing Code and is enforced by the Construction Industries Division; local jurisdictions may adopt amendments.

A plumbing permit is required for new construction, alterations, and replacement of piping or fixtures; minor repairs are exempt.

A plumbing contractor must be licensed and bonded; the license number must appear on permits and contracts.

A journeyman plumber license requires a passing examination and the required supervised experience; the license must be renewed.

A rough-in inspection must occur after piping is installed and before it is covered; a final inspection must occur after fixtures are set and tested.

A water supply test must be at least 100 psi for 15 minutes or at working pressure for 30 minutes; a drainage test must be held for at least 15 minutes.

A gas piping test must be at 1-1/2 times the working pressure but not less than 3 psi for 10 minutes.

A backflow prevention assembly must be tested annually by a certified tester and the report filed with the water purveyor.

A certificate of occupancy may not be issued until the plumbing final inspection is approved and all fees are paid.

The New Mexico Plumbing Code is the Uniform Plumbing Code as amended by the state and enforced by the Construction Industries Division.

A permit must be obtained before work begins; work without a permit is subject to a double fee and a stop-work order.

A plumbing contractor must be licensed and bonded; the license number must appear on permits and contracts.

A journeyman plumber license requires a passing examination and the required supervised experience; the license must be renewed.

A rough-in inspection must occur after piping is installed and before it is covered; a final inspection must occur after fixtures are set.

A water supply test must be at least 100 psi for 15 minutes or at working pressure for 30 minutes; a drainage test must be held for at least 15 minutes.

A gas piping test must be at 1-1/2 times the working pressure but not less than 3 psi for 10 minutes.

A backflow prevention assembly must be tested annually by a certified tester and the report filed with the water purveyor.

A certificate of occupancy may not be issued until the plumbing final inspection is approved and all fees are paid.