Glossary

Active LicenseA contractor license in good standing that has been renewed, has a qualifying individual on file, and meets all bonding and insurance requirements.Licensing AddendumA written change or addition to a contract issued before execution that modifies the original terms.Business & Law ArbitrationA method of resolving disputes outside of court where a neutral third party reviews evidence and makes a binding or non-binding decision.Business & Law As-Built DrawingsRevised drawings submitted after project completion showing exact dimensions, locations, and materials as actually constructed.Construction Asbestos AbatementThe process of removing, encapsulating, or enclosing asbestos-containing materials in a structure to prevent hazardous exposure.Safety Assignment of ContractThe transfer of rights and obligations under a construction contract from one party to another, requiring written consent from all parties.Business & Law

Bid BondA surety bond submitted with a bid guaranteeing that if awarded the contract, the bidder will enter into the contract and provide required performance bonds.Finance BondingA $25,000 surety bond required by the CSLB for all licensed contractors. Protects consumers if a contractor causes damage or fails to complete a project.Licensing Breach of ContractA violation of any terms or conditions in a contract without legal excuse, entitling the non-breaching party to damages or other remedies.Business & Law Building PermitOfficial approval from a local government allowing construction, renovation, or demolition to proceed in compliance with applicable codes.Construction Business & Professions CodeThe California state code governing contractor licensing, including the Contractors State License Law in Sections 7000–7191.Licensing BackchargeA cost charged back to a subcontractor for work they failed to provide or that required correction at the general contractor’s expense.Business & Law Bearing WallA wall that supports the weight of the structure above it and transfers that load to the foundation. Cannot be removed without structural reinforcement.B – General BlockingShort pieces of lumber installed between studs, joists, or rafters to provide structural support, backing for fixtures, or fire stopping.B – General Branch CircuitThe portion of a wiring system extending beyond the final overcurrent device protecting the circuit, supplying one or more outlets or loads.C-10 Electrical Bonding JumperA conductor used to ensure electrical continuity and conductivity between metal parts of an electrical system. Required to maintain the grounding path.C-10 Electrical BTUBritish Thermal Unit — the standard unit of heat energy used to measure heating and cooling capacity in HVAC systems. One BTU raises one pound of water by 1°F.C-20 HVAC Backflow PreventerA device that prevents contaminated water from flowing backward into the potable water supply. Required on irrigation systems and other cross-connection points.C-36 Plumbing Built-Up Roofing (BUR)A low-slope roofing system consisting of multiple layers of bitumen and reinforcing fabrics, topped with aggregate surfacing for UV and weather protection.C-39 Roofing

CSLBCalifornia Contractors State License Board — the state agency responsible for licensing and regulating contractors throughout California.Licensing Certificate of OccupancyA document issued by local government certifying a building complies with applicable codes and is safe for occupancy.Construction Change OrderA written agreement between owner and contractor modifying the original contract scope, price, or schedule after work has begun.Business & Law Civil PenaltyA monetary fine imposed by the CSLB on a contractor for violating the Contractors State License Law or engaging in unlicensed activity.Licensing ContingencyA reserve amount added to a project budget to cover unforeseen conditions, scope changes, or unexpected costs during construction.Finance Contractor’s BondA $25,000 surety bond required by the CSLB for all licensed contractors protecting consumers from losses due to defective work or contract violations.Licensing Concrete SlabA flat, horizontal concrete surface used as a floor or foundation. Can be slab-on-grade, raised, or post-tensioned depending on soil and load conditions.B – General Cripple WallShort stud walls between the foundation and the first floor framing. Require bracing in seismic zones to prevent collapse during an earthquake.B – General Curtain WallA non-structural exterior wall system attached to the building frame that carries only its own weight and resists wind loads, commonly glass and aluminum.B – General Circuit BreakerAn automatically operated switch that protects an electrical circuit from damage caused by overcurrent or short circuit. Can be reset after tripping.C-10 Electrical ConduitA tube or trough used to protect and route electrical wiring. Types include EMT, rigid metal, PVC, and flexible conduit, each suited to different applications.C-10 Electrical Current Transformer (CT)An instrument transformer that produces a current proportional to the primary current. Used for metering and protection in high-voltage applications.C-10 Electrical CFMCubic Feet per Minute — the unit used to measure airflow volume in HVAC systems. Used to size ducts, fans, and air handlers for proper ventilation.C-20 HVAC CompressorThe heart of a refrigeration or air conditioning system. Compresses refrigerant vapor, raising its temperature and pressure before it moves to the condenser.C-20 HVAC CondenserThe outdoor coil in an air conditioning system where refrigerant releases heat absorbed from the building interior into the outside air.C-20 HVAC CleanoutAn access point in a drain or sewer line that allows for inspection and clearing of blockages without disassembling the pipe.C-36 Plumbing Cross ConnectionAny physical connection between a potable water supply and a non-potable source. Must be protected with appropriate backflow prevention devices.C-36 Plumbing California-Friendly PlantingPlant selection and installation practices that minimize water use by using drought-tolerant, native, or Mediterranean climate species appropriate for local conditions.C-27 Landscaping Controller (Irrigation)An automatic timer device that operates irrigation valves on a set schedule. Smart controllers adjust watering based on weather data and soil moisture sensors.C-27 Landscaping Chalk LineA tool used to mark straight reference lines on surfaces before painting. Essential for accurate trim lines, stripes, and pattern work.C-33 Painting Counter FlashingMetal flashing embedded into a wall or chimney that overlaps base flashing to prevent water infiltration at roof-to-wall intersections.C-39 Roofing Cap FlashingSheet metal installed at the top of a wall or parapet to shed water away from the building. Also called coping, it protects the top edge of masonry walls.C-43 Sheet Metal CrimpA technique used to join sheet metal sections by folding and interlocking edges. Provides a tight, weather-resistant connection without fasteners or sealant.C-43 Sheet Metal

DefaultFailure by a contractor to fulfill contract terms without legal excuse, which may trigger performance bond claims or legal action by the project owner.Business & Law DisbursementThe release of funds from a construction loan or escrow account to pay for completed work at various stages of a project.Finance Due DiligenceThe process of thoroughly investigating a project site, contract terms, and applicable regulations before committing to a construction contract.Business & Law Dead LoadThe permanent, static weight of a building’s structural components — framing, roofing, flooring, and fixed equipment — that a structure must continuously support.B – General DriftThe lateral displacement of a building under wind or seismic forces. Controlled through shear walls, moment frames, and diaphragm design in structural engineering.B – General Demand FactorThe ratio of the maximum demand of a system to its total connected load. Used in load calculations to size service equipment and feeders.C-10 Electrical DamperA movable plate inside a duct that controls airflow volume and direction. Used for balancing, zone control, and fire/smoke containment in HVAC systems.C-20 HVAC Dew PointThe temperature at which air becomes saturated with moisture and condensation forms. Critical in HVAC design to prevent moisture damage and mold growth.C-20 HVAC Drain, Waste & Vent (DWV)The system of pipes that removes wastewater and sewage from a building while venting sewer gases to the atmosphere and maintaining proper drainage flow.C-36 Plumbing Drip IrrigationA low-flow irrigation method that delivers water directly to the root zone of plants through emitters. Reduces evaporation and water waste compared to spray systems.C-27 Landscaping Dry Film Thickness (DFT)The thickness of a paint or coating after it has dried. Specified in mils (thousandths of an inch) and critical for proper protection and performance.C-33 Painting DuctSheet metal channels used to distribute conditioned air throughout a building. Sized by volume of airflow required and fabricated from galvanized steel or aluminum.C-43 Sheet Metal Duct LinerInsulation applied to the interior of sheet metal ductwork to reduce heat loss, control condensation, and attenuate sound in HVAC systems.C-43 Sheet Metal

Equipment Grounding ConductorThe conductor that connects the non-current-carrying metal parts of equipment to the system grounded conductor and the grounding electrode conductor.C-10 Electrical Electrical PanelThe distribution board that receives incoming power and distributes it to individual circuits through circuit breakers or fuses. Also called a load center or breaker panel.C-10 Electrical Evaporator CoilThe indoor coil where liquid refrigerant absorbs heat from the building air, cooling it before the refrigerant returns to the compressor as a low-pressure vapor.C-20 HVAC Expansion ValveA metering device that reduces refrigerant pressure and temperature before the evaporator coil. Controls refrigerant flow to match the cooling load.C-20 HVAC EffluentLiquid waste or sewage that flows out of a septic tank or treatment system. In residential plumbing, it refers to the partially treated wastewater entering the leach field.C-36 Plumbing EasementA legal right to use another person’s land for a specific purpose, such as utilities, drainage, or access. Affects what can be built in the easement area.B – General EmitterA small device in a drip irrigation system that releases water at a controlled, slow rate directly to the soil near plant roots. Measured in gallons per hour.C-27 Landscaping EfflorescenceWhite, powdery mineral deposits that appear on masonry or concrete surfaces as water moves through and evaporates, leaving salts behind. Must be removed before painting.C-33 Painting EaveThe lower edge of a roof that overhangs the exterior wall. Protects the wall from water runoff and is a common location for ice dam formation in cold climates.C-39 Roofing Elbow (Duct)A sheet metal fitting used to change the direction of ductwork. Available in various angles and throat radii; proper sizing reduces static pressure loss.C-43 Sheet Metal

FootingThe base of a foundation that distributes the building’s weight across a wider area of soil. Width and depth depend on soil bearing capacity and structural loads.B – General FlashingThin metal or flexible material installed at joints, transitions, and penetrations to prevent water infiltration. Critical at roof-to-wall and window-to-wall intersections.B – General Fire BlockingMaterial used to close concealed cavities in framing to prevent the spread of fire. Required at specific intervals in stud walls and between floors.B – General FeederAll circuit conductors between the service equipment and the final branch-circuit overcurrent device. Sized to carry the calculated load of all downstream circuits.C-10 Electrical Fault CurrentAbnormal current flowing through an unintended path in an electrical system, often due to insulation failure or accidental contact. Can cause fire or equipment damage.C-10 Electrical FurnaceA forced-air heating unit that burns fuel or uses electric resistance to heat air, which is then distributed through ductwork. Rated in BTU/hr output.C-20 HVAC Filter (HVAC)A device that removes airborne particles from the air stream before it passes through the HVAC system. MERV rating indicates filtration efficiency.C-20 HVAC Fixture UnitA unit of measure used to calculate the drainage load a plumbing fixture places on a drainage system. Used to size drain pipes and stacks.C-36 Plumbing FluxA chemical compound applied to copper pipe before soldering to prevent oxidation and help the solder flow into the joint for a watertight seal.C-36 Plumbing French DrainA gravel-filled trench with a perforated pipe that redirects surface water and groundwater away from structures, preventing flooding and soil saturation.C-27 Landscaping FeatheringBlending the edges of a painted area by gradually thinning the coat to create a smooth transition. Used when patching or spot-painting to match existing surfaces.C-33 Painting Flashing (Roofing)Metal or flexible material installed at roof penetrations, valleys, and edges to direct water away from vulnerable areas and into the drainage system.C-39 Roofing FabricationThe process of cutting, forming, and assembling sheet metal components. Includes layout, shearing, bending, and joining operations performed in a shop or field.C-43 Sheet Metal

GirderA large, primary horizontal beam that supports the weight of floor joists or secondary beams. Often steel or engineered lumber in modern construction.B – General GradingThe process of leveling, sloping, or shaping soil on a construction site for drainage, structural support, and compliance with site plan requirements.B – General GFCIGround Fault Circuit Interrupter — a device that detects small ground faults and trips within milliseconds to prevent electrocution. Required near water sources by NEC.C-10 Electrical Grounding Electrode SystemThe network of electrodes and conductors that connects an electrical system to the earth to stabilize voltage and provide a path for fault current.C-10 Electrical GrilleA decorative and functional cover for air return openings in walls or ceilings. Does not regulate airflow — that function is performed by a register or damper.C-20 HVAC Gate ValveA valve that controls water flow by raising or lowering a gate. Designed for fully open or fully closed use — not suitable for flow regulation.C-36 Plumbing GradingShaping the ground surface to control drainage, prevent erosion, and establish proper slope away from structures as required by code.C-27 Landscaping Gloss LevelThe degree of light reflectance in a paint finish, ranging from flat/matte to high-gloss. Higher gloss finishes are more durable and cleanable but reveal surface imperfections.C-33 Painting GranulesSmall mineral particles embedded in the surface of asphalt shingles to protect against UV degradation and provide color. Granule loss indicates shingle aging.C-39 Roofing GaugeA measurement of sheet metal thickness. The higher the gauge number, the thinner the metal. HVAC ductwork commonly uses 26 to 22 gauge galvanized steel.C-43 Sheet Metal

HeaderA horizontal structural member above a door or window opening that transfers loads from above to the supporting studs on each side of the opening.B – General Home RunThe circuit wiring from the last outlet or device on a branch circuit back to the electrical panel. Carries the full load of the circuit.C-10 Electrical Heat PumpA reversible refrigeration system that provides both heating and cooling by moving heat from one location to another rather than generating it through combustion.C-20 HVAC Relative HumidityThe percentage of moisture in the air relative to the maximum it can hold at a given temperature. HVAC systems control humidity for comfort and to prevent condensation.C-20 HVAC Horizontal DrainAny drain pipe installed at less than 45 degrees from horizontal. Must maintain a minimum slope of 1/4 inch per foot toward the building drain.C-36 Plumbing HardscapeThe non-living elements of a landscape including patios, walkways, retaining walls, and driveways. Distinct from softscape which refers to plants and soil.C-27 Landscaping Hiding PowerA paint’s ability to obscure the color or pattern of the surface beneath it. Determined by the type and concentration of pigment in the formulation.C-33 Painting Hip RoofA roof with slopes on all four sides that meet at a ridge. More wind-resistant than a gable roof and requires hip flashing at the sloped ridge intersections.C-39 Roofing HemA fold made in the edge of sheet metal to stiffen the material, eliminate sharp edges, and allow joining. Double hems interlock to form standing seam connections.C-43 Sheet Metal

IndemnificationA contractual obligation where one party agrees to protect another from financial loss or legal liability arising from specified acts or events.Business & Law Insurance CertificateA document issued by an insurer verifying that a contractor carries the required types and amounts of insurance coverage.Finance InspectionA review by a building official at defined stages of construction to verify code compliance. Failing an inspection requires corrections before work can continue.B – General InverterA device that converts DC power from solar panels or batteries into AC power for use in a building. Central to photovoltaic and battery storage systems.C-10 Electrical IAQ (Indoor Air Quality)A measure of the air conditions inside a building including pollutants, ventilation adequacy, humidity, and temperature. Regulated by Title 24 and ASHRAE standards.C-20 HVAC InterceptorA device installed in a drainage system to separate and retain grease, oil, sand, or other harmful substances before they enter the sewer system.C-36 Plumbing Irrigation AuditAn evaluation of an irrigation system’s efficiency, coverage, and distribution uniformity. Required for large systems in many California water districts.C-27 Landscaping Ice & Water ShieldA self-adhering waterproof membrane applied at vulnerable roof areas like eaves, valleys, and penetrations to prevent water infiltration from ice dams and wind-driven rain.C-39 Roofing Insulated DuctDuctwork wrapped or lined with insulation to reduce heat transfer and prevent condensation. Minimum R-values are specified by Title 24 in California.C-43 Sheet Metal

JoistA horizontal structural member that supports floors or ceilings. Spans between beams or bearing walls and is repeated at regular intervals to form the framing deck.B – General Junction BoxAn enclosure that houses electrical wire connections, protecting them from damage and containing potential arc flashes. Must remain accessible per NEC requirements.C-10 Electrical Joint (Plumbing)The connection point between two pieces of pipe or fittings. Joint types include soldered, threaded, push-fit, compression, and solvent-welded depending on the material.C-36 Plumbing Joint PlantingInstalling plants in the gaps between pavers or hardscape elements to soften appearance, reduce runoff, and help stabilize the installation.C-27 Landscaping

LienA legal claim against a property by an unpaid contractor, subcontractor, or supplier. Must be filed within specific deadlines to be enforceable.Business & Law Lien ReleaseA document signed by a contractor or supplier confirming receipt of payment and releasing their right to file a mechanic’s lien on the property.Business & Law License ClassificationA specific category of contractor work a licensee is authorized to perform, such as B (General Building) or C-10 (Electrical).Licensing Live LoadThe variable, movable weight a structure must support — people, furniture, snow, and equipment. Building codes specify minimum live load values per occupancy type.B – General Ledger BoardA horizontal board bolted to the side of a building to support deck joists or a beam. Must be properly flashed and fastened to prevent water intrusion and failure.B – General Load CalculationA mathematical process used to determine the electrical demand of a building and properly size service entrance conductors, panels, and feeders per NEC Article 220.C-10 Electrical Latent HeatHeat absorbed or released during a change of state without a temperature change. In HVAC, it refers to the energy required to remove or add moisture from the air.C-20 HVAC Load Calculation (HVAC)A Manual J calculation that determines the heating and cooling load of a building. Required before sizing HVAC equipment to prevent over or under sizing.C-20 HVAC LavatoryA bathroom sink fixture connected to both hot and cold supply lines and the drain, waste, and vent system. Assigned a specific fixture unit value for pipe sizing.C-36 Plumbing Lateral LineThe supply pipe that runs from the irrigation valve to the sprinkler heads or emitters in a specific zone. Sized based on flow rate and number of heads.C-27 Landscaping Lap MarkA visible line or streak in a paint finish caused by overlapping wet paint onto an already-dried section. Prevented by maintaining a wet edge during application.C-33 Painting Low-Slope RoofA roof with a pitch of less than 3:12. Requires different waterproofing systems than steep-slope roofs including membranes, modified bitumen, or TPO/EPDM systems.C-39 Roofing Lock SeamA mechanical joint formed by interlocking folded edges of sheet metal panels. Provides a watertight, structurally rigid connection without soldering or fasteners.C-43 Sheet Metal

Moment FrameA structural frame designed to resist lateral forces through rigid beam-to-column connections. Used in seismic and wind applications where shear walls are not practical.B – General Meter SocketThe utility-owned enclosure where the kilowatt-hour meter is installed. Located between the utility service and the main disconnect or service panel.C-10 Electrical Manual JThe industry standard calculation method for determining residential heating and cooling loads. Required by California Title 24 before HVAC equipment can be specified.C-20 HVAC Main Shutoff ValveThe primary valve that controls water supply to an entire building. Must be accessible and labeled. Required to be within 5 feet of the water meter in California.C-36 Plumbing MulchOrganic or inorganic material applied over soil surface to retain moisture, suppress weeds, and moderate soil temperature. A minimum 3-inch depth is recommended for most applications.C-27 Landscaping MilOne thousandth of an inch — the standard unit for measuring paint film thickness. Most architectural coatings require 2–4 mils dry film thickness per coat.C-33 Painting Membrane RoofingA continuous waterproof sheet applied to low-slope roofs. Common types include TPO, EPDM, and PVC, each offering different performance and installation characteristics.C-39 Roofing MiterAn angled cut made across the face of sheet metal to create a joint at a corner. Used for aesthetic trim work and decorative sheet metal installations.C-43 Sheet Metal

NECNational Electrical Code — NFPA 70, the standard for safe electrical installation in the United States. Adopted by California with amendments as the California Electrical Code.C-10 Electrical Neutral ConductorThe grounded current-carrying conductor of an electrical system that completes the circuit and carries return current back to the source under normal conditions.C-10 Electrical NATE CertificationNorth American Technician Excellence — an industry credential for HVAC technicians that validates competency in installation, service, and troubleshooting of HVAC systems.C-20 HVAC Nominal Pipe Size (NPS)A standard sizing system for pipe that does not correspond directly to actual dimensions. Used to identify pipe and fittings for compatibility across different manufacturers.C-36 Plumbing Native PlantA plant species that naturally occurs in a region without human introduction. Native plants are adapted to local climate and soil conditions, reducing water and maintenance needs.C-27 Landscaping Nailing ZoneThe designated area on a roofing shingle where fasteners must be placed to achieve proper wind resistance and weatherproofing per manufacturer specifications.C-39 Roofing

OSHAOccupational Safety and Health Administration — the federal agency that sets and enforces workplace safety standards for construction industries.Safety OverheadOngoing business expenses not directly tied to a specific project, such as office rent, insurance, vehicles, and administrative costs.Finance Overcurrent ProtectionFuses or circuit breakers that interrupt current flow when it exceeds the safe capacity of the wiring. Sized per conductor ampacity and NEC requirements.C-10 Electrical Outdoor Air (OA)Fresh air introduced into a building’s HVAC system from outside. Required in minimum quantities by ASHRAE 62.1 and Title 24 to maintain acceptable indoor air quality.C-20 HVAC Overflow DrainA secondary drain opening installed above the primary drain in a bathtub or basin to prevent overflow if the primary drain becomes blocked.C-36 Plumbing OverseedingSpreading grass seed over an existing lawn without tilling. Used to thicken thin turf, introduce improved grass varieties, or establish winter grass in warm-season lawns.C-27 Landscaping OversprayPaint particles that travel beyond the intended surface during spray application. Requires masking and protection of adjacent areas and surfaces before spraying.C-33 Painting Open ValleyA roof valley where metal flashing is exposed and visible between the two roof planes. Provides excellent water drainage and is easier to maintain than a closed valley.C-39 Roofing

Performance BondA surety bond guaranteeing that a contractor will complete a project according to contract terms, protecting the owner if the contractor defaults.Finance Punch ListA list of items that must be completed or corrected before a project is considered finished and final payment is released.Construction Prevailing WageThe minimum hourly wage and benefits required on California public works projects, as determined by the Department of Industrial Relations.Business & Law Post-Tensioned SlabA concrete slab reinforced with high-strength steel cables tensioned after the concrete sets. Common in California for expansive soils and garage floors.B – General Plywood SheathingStructural panels nailed to wall framing to create a shear diaphragm that resists lateral forces. Thickness and nailing pattern determined by engineering requirements.B – General PanelboardA distribution cabinet containing buses, overcurrent devices, and switches that controls and protects multiple circuits. Distinct from a switchboard by its smaller size and cabinet enclosure.C-10 Electrical PlenumA space within a building that is used for air distribution in HVAC systems, such as a ceiling cavity. Materials used in plenums must meet flame-spread and smoke requirements.C-20 HVAC Pressure RegulatorA valve that reduces incoming water pressure to a safe level for building plumbing, typically 60–80 PSI. Required when street pressure exceeds 80 PSI.C-36 Plumbing P-TrapA curved section of drain pipe that holds water to create a seal preventing sewer gases from entering the building. Required under every plumbing fixture.C-36 Plumbing Precipitation RateThe rate at which an irrigation system applies water, measured in inches per hour. Matching precipitation rates within a zone prevents over- and under-watering.C-27 Landscaping PrimerA preparatory coating applied to a surface before the finish coat to improve adhesion, seal porous surfaces, and provide uniform topcoat appearance and performance.C-33 Painting PitchThe slope of a roof expressed as a ratio of vertical rise to horizontal run (e.g., 4:12). Determines roofing material requirements and minimum overlap specifications.C-39 Roofing Plenum-RatedSheet metal ductwork or materials approved for installation in air-handling spaces. Must meet low flame-spread and low smoke-development requirements per UL standards.C-43 Sheet Metal

Qualifying IndividualA person who meets experience requirements and passes the exam to qualify a contractor license — either the owner or a responsible managing employee.Licensing

RetentionA percentage of each progress payment withheld by the owner until project completion, typically 5–10%, to ensure the contractor finishes the work.Finance RMEResponsible Managing Employee — qualifies a contractor’s license by meeting experience requirements and passing the exam on behalf of the licensed entity.Licensing RMOResponsible Managing Officer — an officer of a corporation or member of a partnership who qualifies the contractor license by passing the required exams.Licensing RafterAn inclined structural member that forms the sloped frame of a roof. Spans from the ridge board to the wall plate and supports roof sheathing and covering.B – General Retaining WallA wall designed to hold back soil or other material. Must be engineered for lateral earth pressure and include drainage provisions to prevent hydrostatic buildup.B – General RacewayAny enclosed channel designed to hold wires, cables, or busbars, including conduit, wireways, and cable trays. Protects conductors and provides organizational routing.C-10 Electrical RefrigerantA fluid that absorbs and releases heat as it circulates through an HVAC system. Modern systems use low-GWP refrigerants such as R-410A or R-32 per environmental regulations.C-20 HVAC Return AirAir pulled from the conditioned space back to the HVAC system for reconditioning. Return ducts must be sized to match supply air volume for proper system balance.C-20 HVAC Rough-InThe installation of supply and drain pipes within walls and floors before wall finishes are applied. Inspected and approved before being covered.C-36 Plumbing Runoff CoefficientA value representing the fraction of rainfall that becomes surface runoff. Used in stormwater calculations and landscape design to size drainage features.C-27 Landscaping Roller NapThe thickness of the fabric on a paint roller cover. Thicker naps hold more paint and are used for rough surfaces; thinner naps produce smoother finishes on flat surfaces.C-33 Painting Ridge CapSpecially formed shingles or metal installed at the peak of a roof to seal the ridge and provide a finished, weatherproof termination of the two roof slopes.C-39 Roofing ReducerA sheet metal fitting used to transition between two different duct sizes. Must be tapered at the proper angle to minimize turbulence and static pressure loss.C-43 Sheet Metal

SubcontractorA licensed contractor hired by a general contractor to perform a specific portion of work. Must hold the appropriate license for the work being performed.Business & Law SuretyA third-party company that guarantees a contractor’s obligations through a bond, promising to pay or complete work if the contractor defaults.Finance Stop NoticeA legal remedy available to unpaid contractors or suppliers that requires a lender or owner to withhold construction funds until the claim is resolved.Business & Law Shear WallA structural wall with sheathing and specific nailing patterns designed to resist lateral forces from wind or earthquakes. Location and size determined by engineering.B – General StudA vertical framing member in a wall, typically 2×4 or 2×6 lumber spaced 16 or 24 inches on center. Supports vertical loads and provides attachment for wall finish materials.B – General SetbackThe minimum required distance between a structure and property lines, streets, or other features as established by local zoning ordinances.B – General Service EntranceThe conductors and equipment connecting the utility power supply to the building’s wiring system, including the meter socket, service conductors, and main disconnect.C-10 Electrical Short CircuitAn abnormal, low-resistance connection between two conductors of different potential. Causes extremely high fault current that must be interrupted by overcurrent protection.C-10 Electrical SEERSeasonal Energy Efficiency Ratio — the cooling efficiency rating for air conditioners and heat pumps. Higher SEER values indicate greater efficiency. California minimum is SEER2 14.3.C-20 HVAC Static PressureThe resistance to airflow in a duct system measured in inches of water column. Excessive static pressure reduces airflow and strains blower motors.C-20 HVAC StackA vertical pipe that receives waste from branch drains on multiple floors and carries it to the building drain. The stack vent extends through the roof to atmosphere.C-36 Plumbing Slope (Drain)The grade applied to horizontal drain pipes to ensure gravity flow. The California Plumbing Code requires a minimum of 1/4 inch per foot for pipes 3 inches and smaller.C-36 Plumbing SoftscapeThe living elements of a landscape including plants, trees, shrubs, grass, and soil. Requires ongoing maintenance as plants grow and seasonal conditions change.C-27 Landscaping Soil AmendmentMaterial added to soil to improve its physical or chemical properties for plant growth, including compost, gypsum, perlite, and sulfur for pH adjustment.C-27 Landscaping SubstrateThe underlying surface to which paint or a coating is applied. Substrate type determines the appropriate primer, application method, and finish system selection.C-33 Painting Surface PreparationThe process of cleaning, sanding, patching, and priming a surface before applying finish coats. The single most important factor in paint adhesion and longevity.C-33 Painting Starter StripA first row of roofing material installed at the eave edge before the first full course of shingles. Provides a solid base and seals the bottom of the first shingle course.C-39 Roofing SoffitThe underside of a roof overhang. Vented soffits allow air to enter the attic from the eaves as part of a balanced attic ventilation system.C-39 Roofing Snap LockA standing seam roof panel system with a pre-formed leg that snaps onto a fixed clip during installation. Allows for thermal expansion without exposed fasteners.C-43 Sheet Metal Sheet Metal ScrewA self-tapping fastener designed to join sheet metal components. Hex-head screws with neoprene washers are used for weatherproof connections in roofing applications.C-43 Sheet Metal

Title 24California’s Building Energy Efficiency Standards that regulate energy use in new and existing buildings, including requirements for insulation, lighting, HVAC, and water heating.B – General TrussA prefabricated structural framework of triangular units used to support roofs or floors. More efficient than conventional framing for spanning long distances.B – General TransformerAn electrical device that transfers energy between circuits through electromagnetic induction, stepping voltage up or down. Used to change utility voltage to usable building voltage.C-10 Electrical ThermostatA control device that monitors space temperature and signals the HVAC system to heat or cool as needed. Smart thermostats learn usage patterns and optimize energy use.C-20 HVAC Ton of CoolingA unit of air conditioning capacity equal to 12,000 BTU/hr — the amount of heat required to melt one ton of ice in 24 hours. Used to rate AC system capacity.C-20 HVAC Trap SealThe water retained in a trap that creates a barrier against sewer gases. A minimum 2-inch seal depth is required by the California Plumbing Code.C-36 Plumbing TranspirationThe process by which plants release water vapor through their leaves. Combined with evaporation, it is used to calculate evapotranspiration (ET) for irrigation scheduling.C-27 Landscaping Tint BaseA paint formulated with minimal pigment that accepts colorants to produce custom colors. Different bases (pastel, medium, deep, clear) accept different amounts of colorant.C-33 Painting TPOThermoplastic Polyolefin — a single-ply roofing membrane popular for low-slope commercial roofs. Heat-welded seams and reflective white surface make it energy efficient.C-39 Roofing Take-OffThe process of measuring and quantifying duct lengths, fittings, and accessories from plans to determine material quantities for fabrication and installation.C-43 Sheet Metal

UnderlaymentA secondary layer of weather protection installed directly on roof sheathing beneath finish roofing materials. Provides backup protection if water infiltrates the outer layer.B – General Ungrounded ConductorThe current-carrying conductor of an electrical circuit that is not intentionally grounded — commonly called the “hot” wire. Identified by black, red, or other colors per NEC.C-10 Electrical UV Protection (Refrigerant Lines)Insulation or jacketing applied to refrigerant suction lines exposed to sunlight to prevent UV degradation and maintain insulation effectiveness.C-20 HVAC UnionA three-piece threaded fitting that allows pipes to be connected and disconnected without cutting. Used where future maintenance or equipment replacement is anticipated.C-36 Plumbing Underlayment (Roofing)A water-resistant or waterproof layer installed over roof sheathing. Types include felt, synthetic, and self-adhering membranes. Required under all finish roofing materials.C-39 Roofing

Vapor BarrierA material with low permeability to water vapor used to reduce moisture migration through walls, floors, and ceilings. Required in specific climate zones by Title 24.B – General Voltage DropThe reduction in voltage along a conductor due to resistance. NEC recommends limiting voltage drop to 3% on branch circuits and 5% total from service to load.C-10 Electrical VRF SystemVariable Refrigerant Flow — a multi-zone HVAC system that varies refrigerant flow to multiple indoor units from a single outdoor unit. Highly efficient for commercial buildings.C-20 HVAC Vent StackA vertical pipe that provides air circulation to the drainage system, equalizes pressure to maintain trap seals, and exhausts sewer gases through the roof.C-36 Plumbing Valve BoxA protective enclosure installed flush with the ground surface that houses irrigation valves and allows access for maintenance and adjustment.C-27 Landscaping VOC (Volatile Organic Compounds)Carbon-based chemicals in paint that evaporate at room temperature. California has strict VOC limits for architectural coatings to reduce air pollution and health hazards.C-33 Painting ValleyThe internal angle formed where two roof planes meet. Valleys concentrate water runoff and are among the most vulnerable areas of a roof, requiring proper flashing.C-39 Roofing Volume DamperA manually or automatically adjustable plate installed inside ductwork to regulate airflow to individual zones or outlets. Used during air balancing.C-43 Sheet Metal

Workers’ CompensationMandatory insurance covering medical expenses and lost wages for employees injured on the job. Required for all contractors with employees in California.Finance WarrantyA contractor’s guarantee that completed work will remain free from defects for a specified period, typically one year for most residential construction.Business & Law Weep ScreedA metal strip at the base of an exterior stucco system that allows trapped moisture to escape and prevents the stucco from sitting on the foundation or slab.B – General Wire Gauge (AWG)American Wire Gauge — the standard system for sizing electrical conductors. Smaller AWG numbers indicate larger wire. Conductor size determines maximum ampacity.C-10 Electrical Wet Bulb TemperatureA temperature measurement that accounts for humidity by using a thermometer with a moistened wick. Used in HVAC design to determine cooling coil performance.C-20 HVAC Water HammerA pressure surge in plumbing caused by the sudden stopping of water flow, creating a banging noise. Prevented with air chambers or water hammer arrestors.C-36 Plumbing Water HeaterAn appliance that heats and stores domestic hot water. Must be seismically strapped in California, have a T&P relief valve, and meet current energy efficiency requirements.C-36 Plumbing Water BudgetThe maximum amount of water a landscape may use annually, calculated based on the site’s reference evapotranspiration and irrigated area. Required under MWELO in California.C-27 Landscaping Wet EdgeThe leading edge of freshly applied paint that has not yet dried. Maintaining a wet edge during application prevents lap marks and ensures a uniform finish.C-33 Painting Waterproofing MembraneA continuous impermeable layer applied to below-grade or wet area surfaces to prevent water infiltration. Distinct from water-resistant barriers used in above-grade applications.C-39 Roofing WeldA permanent joint formed by fusing sheet metal components using heat and sometimes filler material. TIG welding is common for stainless and aluminum; MIG for heavier gauges.C-43 Sheet Metal

ZoningLocal government regulations that control how land can be used and what structures can be built in designated areas. Determines allowable uses, height limits, and setbacks.B – General Zone ControlAn HVAC system design that allows different areas of a building to be heated or cooled independently using separate thermostats and dampers or equipment.C-20 HVAC Zone ValveAn automatic valve that opens and closes to control water flow to a specific irrigation zone. Operated by the irrigation controller on a timed schedule.C-27 Landscaping