CA C-36 Plumbing cheat sheet

The California Plumbing Code is Title 24, Part 5 of the California Code of Regulations; it adopts the Uniform Plumbing Code with state amendments and governs plumbing installations in California.

A permit is required before installing or altering DWV piping, water piping, gas piping, water heaters, and fixtures; code-listed ordinary repairs are the limited exception.

The C-36 classification covers installation, repair, and maintenance of plumbing systems; licensing requires qualifying experience, examination, bond, and workers compensation compliance.

Cross-connection protection follows hazard level: an air gap for severe hazard, an RPZ for high hazard with backpressure, a DCVA for low hazard, and PVB or AVB only for listed applications.

Potable and nonpotable piping must be physically separated; reclaimed water piping is purple and labeled to prevent cross-connections.

Local jurisdictions may adopt plumbing amendments stricter than the California Plumbing Code; the stricter adopted requirement governs work in that jurisdiction.

Concealed plumbing requires rough-in inspection before covering; final inspection confirms fixture installation, testing, labeling, and accessible valves.

Pipe, fittings, valves, and fixtures must be listed and approved for the application; manufacturer instructions apply unless they conflict with the adopted code.

Minimum horizontal drainage slope is 1/4 inch per foot for pipe 2 1/2 inches and smaller and 1/8 inch per foot for pipe 3 inches and larger.

A fixture trap arm must be vented within the distance allowed by code for its pipe size and must not fall more than one pipe diameter before the vent connection.

Each fixture trap must maintain a liquid seal 2 to 4 inches deep; traps must be self-cleaning and accessible for cleaning or removal.

Cleanouts are required at the base of each stack, at horizontal drainage intervals not exceeding 100 feet, and where aggregate direction changes exceed 135 degrees.

Drainage fixture unit values commonly used are water closet 3, lavatory 1, and bathtub or shower 2; one bathroom group is typically 6 DFU.

A backwater valve is required for fixtures that drain below the overflow level of the upstream manhole; it must remain accessible for service.

A vent terminal through a roof must extend at least 6 inches above the roof surface and be located away from windows, doors, and air intakes as required by code.

Every building must have at least one main vent through the roof; a stack vent connects the highest fixture branch to the vent system.

Static water pressure at fixtures is limited to 80 psi; a pressure-reducing valve is required where street pressure exceeds that limit and must be accessible.

Elevation changes water pressure by about 0.433 psi per foot; a 10-foot rise reduces pressure by about 4.33 psi and must be included in sizing.

Water pipe sizing uses fixture units, developed length, available pressure, elevation change, and friction loss through pipe and fittings.

Backflow prevention selection follows hazard: air gap, RPZ, DCVA, PVB, or AVB; testable assemblies require annual testing by a certified tester.

A closed water system with a check valve or backflow preventer requires an expansion tank or listed relief device to absorb thermal expansion.

Water hammer arrestors are installed near quick-closing valves and appliances to absorb pressure surges and must remain accessible.

PEX piping must be protected from ultraviolet light, abrasion, and excessive bending; allow slack for expansion and follow manufacturer bend radii.

Main shutoff and fixture shutoff valves must be accessible; drain valves are installed at low points to allow system drainage.

California maximum fixture rates include 1.28 gallons per flush for water closets, 0.125 gallons per flush for urinals, 1.2 gallons per minute for lavatories, and 1.8 gallons per minute for showerheads.

A water closet requires at least 15 inches from its centerline to a side wall, 30 inches of clear width, and 21 inches of clearance in front.

Fixture traps must hold a 2-to-4-inch seal; the fixture outlet and trap arm must be sized and installed to preserve the seal.

Floor drains require a trap primer where trap seal evaporation would allow sewer gas to enter the building.

Accessible fixtures require clear floor space, mounting heights, grab bars, and controls that comply with the California Building Code accessibility chapters.

Escutcheons are required at wall and floor penetrations to close openings around piping and support a finished appearance.

Plumbing fixtures and faucets must be listed for the application; lead-bearing solder and flux are prohibited on potable water systems.

A temperature-and-pressure relief valve discharges through full-size pipe without valves or traps and terminates 6 inches above the floor or outside in a safe location.

Water heaters require two seismic straps: one in the upper third and one in the lower third, made of 24-gauge, 1.5-inch-wide metal secured to framing.

A water heater located where leakage causes damage requires a drain pan at least 1.5 inches deep with a 3/4-inch drain to an approved location.

A closed potable water system requires an expansion tank or listed relief device to control pressure rise from thermal expansion.

Combustion air openings and flue clearances must follow the code and manufacturer instructions; stored combustibles must not block openings.

Hot water delivered to fixtures is limited to 120 degrees Fahrenheit for safety unless a higher temperature is specifically permitted.

Recirculation systems require a check valve or thermosiphon arrangement to prevent unwanted flow and maintain hot water temperature.

Fuel gas pipe sizing uses the longest run, total BTU-per-hour load, available pressure, and the code sizing tables; elevation and regulator pressure affect capacity.

A sediment trap is installed downstream of the appliance shutoff valve and as close as practical to the appliance inlet to protect controls.

A flexible appliance gas connector must not exceed 6 feet, must not be concealed, and must not pass through walls, floors, or ceilings.

Corrugated stainless steel tubing must be bonded to the grounding electrode system with a listed clamp and conductor, commonly 6 AWG copper.

Fuel gas piping is pressure-tested before appliances are connected; the test pressure and duration must meet code, and regulators and appliance valves are isolated or protected.

An accessible gas shutoff valve is required at each appliance; the valve must be clearly identified and within the allowed distance from the appliance.

Combustion air and venting must be sized for the appliance input and installation location; improper air supply causes incomplete combustion and carbon monoxide.

Total pump head equals static elevation change plus friction loss plus pressure head; convert psi to feet by multiplying psi by 2.31.

Pumps in series add head at the same flow; pumps in parallel add flow at the same head, and selection must match the system curve.

Hydronic systems require an expansion tank and air separator near the boiler; air elimination protects circulators and reduces noise and corrosion.

A circulator is selected for the required flow and head loss of the longest hydronic circuit, including fittings, valves, and terminal units.

A sump pump discharge requires a check valve and, where required, an air bleed hole to prevent backflow and air locking.

Greywater and reclaimed water systems require permits, approved piping identification, and separation from potable water and food-handling areas.

Specialty systems such as solar hot water and rainwater harvesting must use listed components and backflow protection approved for the application.

At a scale of 1/4 inch equals 1 foot, one inch on the drawing represents 4 feet actual; multiply a measured drawing length by 48 to obtain actual inches.

To convert slope in inches per foot to percent, multiply by 100 and divide by 12; a 1/4-inch-per-foot slope equals about 2.08 percent.

An isometric drawing shows vertical, horizontal, and depth runs; pipe lengths must be measured along each run rather than scaled as a straight line.

A material takeoff counts fixtures, valves, fittings, hangers, and pipe by size and length, then adds a waste allowance for cuts and field changes.

Rough-in dimensions are taken from finished floor, finished wall, and fixture centerlines; verify them against approved submittals before installation.

Plan symbols identify pipe types, valve types, drain direction, vent connections, and fixture locations; a legend must be checked before takeoff.

Elevations and benchmarks establish invert and finish-floor levels; slope and grade are calculated from those reference elevations.

Cal/OSHA requires a protective system for trenches 5 feet or deeper unless a competent person determines stable rock; inspections occur before entry and as conditions change.

Extension ladders are set at a 4-to-1 slope and extend at least 3 feet above the landing; they must be secured and inspected before use.

Confined-space entry requires hazard evaluation, atmospheric testing, ventilation, an attendant, and rescue provisions before entry.

Hot work such as soldering requires removal of combustibles, a fire watch, and monitoring during work and for at least 30 minutes afterward.

Lockout/tagout procedures isolate electrical, gas, and water energy before repair or maintenance; stored pressure must be relieved.

Personal protective equipment includes safety glasses, gloves, hearing protection, and respiratory protection matched to the task hazard.

Lead and asbestos-containing materials in older buildings require disturbance controls and testing before cutting, soldering, or demolition.