Speak plumber.
Every term your plumber uses, in plain English — so the quote makes sense and nothing gets lost in translation.
1.6 gallons per flush (gpf) is the federal maximum for new residential toilets, set by the Energy Policy Act of 1992 and…
ABS cement is the black solvent cement used to join ABS DWV pipe and fittings. It contains MEK (methyl ethyl ketone) plus…
ABS pipe (acrylonitrile butadiene styrene) is the black, rigid thermoplastic that dominates drain, waste, and vent (DWV) piping in Washington homes. It's…
An access panel is a removable panel — typically a metal-rimmed framed cutout in drywall, or a plastic snap-in plate — placed…
A bladder accumulator is a pressurized tank with a synthetic-rubber bladder inside that separates compressed air from water. It's the modern form…
Acidic-water corrosion is what happens when water with pH below 7 — soft and low in alkalinity — attacks the inside of…
An activated carbon filter uses granular carbon (GAC) or carbon block to adsorb chlorine, chloramine, organic compounds, and bad tastes from water.…
An adjustable wrench is a smooth-jaw wrench whose movable jaw is set by a knurled worm screw. It turns hex nuts and…
A faucet aerator is the small unscrewable insert at the tip of a faucet spout. It combines a screen, a flow regulator,…
An aerobic treatment unit (ATU) is a mechanically aerated septic alternative used where soil conditions make a standard gravity (anaerobic) septic system…
Aging pipe contamination is the slow leaching of metals — lead, copper, zinc, iron — from old plumbing materials into household water.…
An air admittance valve (AAV) is a one-way valve that admits air into a fixture's drain when negative pressure threatens to siphon…
An air chamber is the legacy water-hammer cushion: a vertical capped pipe stub above each fixture's supply tee, designed to compress and…
A plumbing air gap is the vertical separation between a faucet or supply outlet and the flood-rim level of the basin below…
An air lock is a trapped pocket of air at a high point in your plumbing that physically blocks water from flowing…
An air-source heat pump (ASHP) extracts heat from outside air and moves it indoors using a refrigerant cycle. It heats in winter…
An alcove tub or shower is the standard residential bath layout where the tub or shower fits between three walls — left,…
An anaerobic septic system is the standard gravity-fed septic setup found on most rural Washington properties. A buried tank holds raw sewage…
An angle stop is the small right-angle shutoff valve installed where the water supply emerges from the wall to feed a fixture…
In Washington, approved backflow assemblies — the RPZ on a high-hazard cross-connection, the DCVA on a fire sprinkler, the PVB on an…
An anode rod is a magnesium or aluminum-zinc rod threaded into the top of a glass-lined steel water-heater tank. It corrodes preferentially…
An anti-scald valve is the shower or tub-shower control valve that prevents sudden hot-water surges when someone flushes a toilet or starts…
An apron tub has an integral finished front skirt — the "apron" — that sits flush with the floor; one face is…
An aquifer is an underground layer of porous rock, sand, or gravel that holds and transmits groundwater. Wells produce water by tapping…
An artesian well is a well drilled into a confined aquifer — a water layer trapped between impermeable strata — where natural…
Induced siphonage (sometimes called aspiration) is trap-seal loss caused by another fixture's discharge — not the trap's own. When water moves through…
An atmospheric vacuum breaker (AVB) is a backflow device that opens to atmosphere when supply pressure drops below atmospheric, admitting air to…
An automatic shutoff valve is a motorized valve installed on the main water supply that closes automatically when integrated sensors detect a…
B-vent is a double-wall galvanized metal flue used to vent atmospheric (natural-draft) gas water heaters and furnaces. The air gap between inner…
Back pressure is one of the two mechanisms that drives backflow. It occurs when downstream pressure (in a connected non-potable or contaminated…
Back siphonage is the backflow mechanism that occurs when supply-side pressure drops below atmospheric — a vacuum — pulling contaminated water from…
Backer board is the rigid cementboard, fiber-cement, or glass-mat-faced gypsum panel installed as the substrate behind tile in tub and shower walls…
Backflow is reverse flow in a plumbing system — water moving backward from downstream toward the supply. The concern is contamination: contaminated…
Backflow preventer is the umbrella term for any device that prevents reverse flow from a downstream connection into a potable supply. Specific…
A backwater valve (BWV, sewer check valve) is a one-way check valve installed on a building drain or basement-fixture branch. It allows…
A ball float is the hollow brass or plastic ball on a long arm in an older toilet tank. As the tank…
A ball valve is a quarter-turn shutoff valve with a bored ball as the closure element — when the bore aligns with…
A ball valve faucet is a single-handle faucet that mixes hot and cold by rotating a perforated metal or plastic ball inside…
A ballcock valve is the older mechanical toilet fill valve — a brass body with a plunger or diaphragm at the inlet,…
Baseboard heating is a hydronic emitter built from a copper tube wrapped in aluminum heat-dissipation fins, mounted along the base of an…
Basement drainage is the family of systems that keep water out of below-grade space and move it out once it gets in.…
A basin wrench is a long-shafted specialty wrench with a swiveling, spring-loaded jaw at one end. It exists for one job: reaching…
A basket strainer is the threaded drain assembly that sits in the bottom of a kitchen sink bowl. The strainer body drops…
A battery-backup sump pump is a secondary pump that runs during the AC power outage when a primary sump pump can't. Two…
A bidet is a fixed bathroom fixture for personal hygiene cleansing of the perineal area, typically installed beside the toilet. Two designs…
A bidet toilet is a toilet with built-in spray-wash hygiene functions. The term covers two formats: a bidet seat that replaces a…
Black iron pipe is threaded steel pipe with a dark mill-scale finish, used in Washington homes for natural gas distribution and fuel…
Blue-water corrosion is when household water comes out visibly blue in a glass — distinct from the blue-green stains that mark chronic…
A boiler drain is the 3/4" hose-thread valve installed on a hydronic boiler or near-boiler piping that lets you drain, flush, or…
A bonding clamp is a code-listed metal clamp that secures a bonding (grounding) wire to a metal pipe. The National Electrical Code…
A bonnet nut is the large external nut threaded onto a faucet body that retains the stem assembly or cartridge. Loosen it…
A borehole is the small-diameter hole a driller bores into the ground to reach an aquifer. The casing, screen, pump, and drop…
The bowl horn (or discharge horn) is the projecting outlet ring on the bottom of a toilet bowl. It presses into the…
A branch drain line is the horizontal drain that carries wastewater from one fixture (or a small group of fixtures on the…
A brazed copper joint uses a high-temperature filler metal (silver-bearing alloy) that melts above 840°F. It's used in refrigeration lines, fire-suppression systems,…
The brine tank is the cylindrical salt-and-water tank next to a water softener's resin tank. It holds the saturated salt brine that…
A BTU rating (BTU/h) is the heat-input rating stamped on every gas appliance nameplate — the amount of energy it burns per…
The building drain is the lowest horizontal drainage pipe inside a building. It collects every stack and branch on its way to…
A building permit (often issued as a "plumbing permit" sub-type for water and drain work) is the local building department's authorization for…
A butterfly valve is a quarter-turn valve with a flat circular disc that pivots on a central shaft inside the pipe. When…
A bypass valve on a water softener lets you route water around the softener without shutting off water to the house —…
Calcification of a valve is mineral buildup on the stem and seat of a shutoff or stop valve until the mechanism seizes…
A cap is a closure fitting that slips over the outside of a pipe end and seals it. It's the female counterpart…
A carbon monoxide (CO) alarm is a small battery-, plug-, or hardwired device that monitors air for carbon monoxide and sounds an…
The carbon monoxide (CO) hazard is the risk of poisoning from carbon monoxide gas — a colorless, odorless, tasteless byproduct of incomplete…
A cartridge faucet uses a sealed, cylindrical insert — the cartridge — to control hot/cold mixing and shutoff in a single replaceable…
A cartridge puller is a manufacturer-specific extraction tool that threads onto a stuck faucet cartridge stem and uses a screw mechanism to…
Cast iron pipe is the dominant pre-1970 drain, waste, and vent (DWV) material in Washington homes — the heavy, dark gray pipe…
Cast iron soil pipe is heavy, gray, drainage-grade pipe that was the residential DWV standard in Washington until roughly 1970. It comes…
Caustic soda drain cleaner is a strong-base (sodium hydroxide) drain opener. It reacts exothermically with water, saponifies grease, and dissolves hair and…
A ceramic disc faucet uses two precision-ground ceramic discs — one fixed, one moving — that mate face-to-face and slide against each…
A cesspool (or cesspit) is a sealed underground tank that receives household sewage with no outlet. It must be pumped out periodically.…
Channel-lock pliers are tongue-and-groove adjustable pliers — long-handled, multi-position, with serrated jaws that bite slip nuts and pipe. They are the single…
A check valve is a one-way valve that permits flow in one direction only — opens automatically under forward pressure, closes automatically…
A cinch clamp is a stainless-steel ring with an integrated tab that pinches closed when squeezed by a cinch tool. Slide it…
A clawfoot bathtub is a period-style freestanding cast-iron tub on four decorative feet — typically ball-and-claw, giving the style its name. Standard…
A cleanout is a capped access fitting on a drain line that lets a plumber insert a snake, hydro-jet head, or camera…
A closed system is created when a check valve or pressure-reducing valve (PRV) blocks heated water from flowing back to the utility…
A closet auger is a specialty drain snake designed specifically for clearing toilet trap clogs. It has a 90-degree crook at the…
A closet bend is the long-sweep 90-degree elbow that connects a toilet's closet flange to the horizontal branch drain or soil stack…
Closet bolts (also called floor bolts) are the two T-head brass bolts that secure a toilet bowl to the closet flange in…
A closet flange (or toilet flange) is the slotted ring at floor level into which closet bolts slide and a toilet bowl…
A cold-climate ASHP (CC-ASHP) is an air-source heat pump engineered to maintain heating capacity and reasonable efficiency at low outdoor temperatures —…
Coliform bacteria are an indicator group, not a specific pathogen. Their presence in drinking water means surface contamination — soil, runoff, sewage,…
A collapsed sewer line is structural failure of the buried lateral between the home and the public main — total or near-total.…
A combined sewer carries sanitary waste and storm runoff in a single pipe. It's the legacy default in pre-WWII US cities and…
A comfort-height toilet has a bowl rim 17 to 19 inches above the finished floor — closer to a standard chair (17…
A common vent is a single vent that serves two fixtures placed back-to-back or side-by-side on the same horizontal branch at the…
A compression faucet is the oldest still-common faucet design — a threaded brass stem with a rubber washer at the bottom. Turning…
A compression fitting joins two pipes by squeezing a brass ferrule (the "olive" or "compression ring") onto the pipe wall as a…
A condensate drain carries the acidic water that condensing tankless water heaters and condensing boilers produce when they pull extra heat out…
A condensing boiler is a high-efficiency gas hydronic boiler that uses a secondary heat exchanger to extract latent heat from cooling flue…
A console sink is a bathroom sink that mounts to the wall and rests on two front legs. It sits between a…
A continuous waste tee is the slip-joint fitting that joins the two tailpieces of a double-bowl sink into a single drain run…
Copper leaching is the release of dissolved copper from pipe walls into household water — usually driven by corrosive water chemistry. You…
Corrosion is the chemical or electrochemical breakdown of metal pipes and fittings. In Washington plumbing, it shows up as pinhole leaks in…
A corrosion inhibitor is a chemical added to a closed hydronic heating loop to suppress rust on steel and aluminum components, scale…
Corrosive water is water that chemically attacks metal pipes from the inside — typically because of low pH (below 7), low alkalinity,…
A coupling is the simplest pipe fitting — a sleeve or socket that joins two pipes end-to-end. Variants exist for every joining…
CPVC pipe (chlorinated polyvinyl chloride) is cream- or tan-colored rigid plastic supply pipe rated for both hot and cold potable water —…
A PEX crimp ring is an annealed (soft) copper ring slid over a PEX pipe and around a barbed fitting, then deformed…
Crimping pliers compress a copper crimp ring or stainless cinch clamp onto a PEX-over-barb fitting to make a permanent water-tight joint. There…
A cross-connection is any actual or potential physical link between a potable water supply and a non-potable source — or between potable…
A cross-connection control program (CCCP) is the regulated system a public water utility uses to prevent contamination from flowing backward into the…
Cryptosporidium is a single-celled parasite (protozoan) whose oocyst — its dormant, transmissible form — has a thick wall that resists standard chlorine…
CSST (corrugated stainless steel tubing) is a thin-walled, flexible gas pipe used in many homes built or remodeled since the 1990s. Most…
A cup plunger is the flat-rimmed rubber plunger you use on sinks, tubs, and showers. It alternately compresses and decompresses water in…
A curb key is the long T-handled rod that reaches down into a stop box to operate the buried curb stop —…
A curb stop is the utility's buried shutoff valve on your water service line, sitting in the public right-of-way just outside your…
A curbless shower has no raised curb at the entry — the bathroom floor and the shower floor are continuous, with the…
Cured-in-place pipe (CIPP) is a polymer-resin-saturated fabric liner that's inverted or pulled into an existing damaged pipe and then cured — by…
A dead leg is a section of pipe that gets little or no flow — typically a long branch to a rarely-used…
A deburring tool is a small handheld tool that shaves the burr off the inside (and sometimes outside) of a freshly cut…
A deck plate is a decorative metal plate that sits between a faucet body and the sink deck, covering extra holes left…
Dezincification is a corrosion mechanism in brass alloys where zinc selectively dissolves out, leaving a porous copper-rich matrix that fails structurally. It's…
A dielectric union is a fitting that electrically isolates two dissimilar metals at a connection — typically copper to galvanized steel. Without…
A dip tube is a plastic tube that hangs from the cold-water inlet at the top of a tank water heater and…
A dishwasher air gap is a small chrome fitting mounted at the sink deck or counter, with the dishwasher drain hose entering…
A disposer Allen wrench is a ¼-inch hex key that fits the bottom of every major-brand garbage disposal. Inserted into the hex…
The disposer reset button is a small red button on the underside of every standard garbage disposal. When the motor draws too…
A distribution box (or D-box) is a small concrete or plastic chamber downstream of the septic tank that splits the effluent stream…
A diverter is the small internal valve in a kitchen faucet (or tub spout) that switches water from one outlet to another…
A diverter tub spout has a small lift rod (or knob) on top of the spout. Lifting the rod engages an internal…
A double check valve assembly (DCVA) is two independently-acting spring-loaded check valves in series, with a shutoff valve at each end and…
A downspout extension is the rigid or flexible pipe that carries roof runoff at least 4 feet (ideally 10) away from the…
A drain auger — also called a drain snake or plumber's snake — is a coiled spring-steel cable inside a drum housing…
A drain bladder is a rubber bag with a garden-hose inlet and a small water-jet outlet. You push it into the drain,…
A drain cock is a small valve installed at the low point of a piping section — or on equipment like a…
A drain pan is a galvanized, aluminum, or plastic pan installed beneath a tank water heater and plumbed to a drain. It…
A drain pipe is any pipe that carries wastewater out of a home by gravity. Most homeowners use the phrase as an…
A drain shoe is the elbow under the tub that bolts to the underside of the drain spud and turns toward the…
Drain slope is the downward pitch of a horizontal drain, set so wastewater flows fast enough to carry solids but slow enough…
A drain valve is the hose-thread spigot at the bottom of a tank water heater used for flushing and service draining. Most…
Draining and flushing a water heater clears mineral sediment from the bottom of the tank — the stuff that causes popping noises,…
A drain-and-waste valve combines a shutoff with a small bleed or drain port on the downstream side. Closing the valve isolates the…
A drain-waste-overflow kit (DWO) is a packaged tub-drain assembly with all the components needed to plumb a tub: drain shoe, drain spud,…
A drainfield (also leach field, soil absorption system, or SSAS in Washington terminology) is the network of perforated lateral pipes laid in…
The drainfield reserve area is a designated, undisturbed parcel — at least equal in size to the active drainfield — set aside…
A drilled well is the standard modern private well: a rotary or percussion rig advances steel or PVC casing into the ground,…
Drip irrigation delivers water slowly at the root zone of plants through low-flow emitters along a small-diameter line. It uses 30–50% less…
A driven well, also called a sand point, is a shallow well made by hammering a small-diameter steel pipe with a perforated…
A drop-ear elbow is a 90-degree fitting with two predrilled mounting tabs ("ears") that screw to a stud or backer board. It's…
A drop-in sink — also called a self-rimming sink — has a wide flange that rests on top of the counter, with…
A drum trap is a cylindrical canister trap installed flush with the floor, with the inlet at the bottom and the outlet…
A dry-fired element is an electric water-heater heating element that burned out because power was turned on while the tank was empty…
A drywell is a subsurface gravel-filled pit that receives roof runoff from downspouts and lets it infiltrate into the surrounding soil. It's…
A dual check valve is two independent spring-loaded checks in series in a compact assembly, typically without test cocks. Listed under ASSE…
A dual-flush toilet has two flush options — full flush at about 1.28 gpf for solids and reduced flush at about 0.8…
A dug well is a wide-bore, shallow well — typically 3 to 10 feet across and 10 to 30 feet deep —…
The DWV system — short for drain-waste-vent — is the gravity-driven half of your home's plumbing. It carries wastewater out through drains…
An earthquake gas shutoff valve (EGSV) is an automatic valve installed in the gas line near the meter that closes when ground…
The ECO (Energy Cut-Off) or high-limit thermostat is a non-self-resetting safety switch on every electric water heater. It trips when stored water…
An effluent filter is a removable cartridge installed in a septic tank's outlet baffle. It blocks solids and floating material — hair,…
An elbow is the basic direction-change fitting in plumbing. Standard angles are 90, 45, 22.5, and (less common) 60 degrees. Available in…
An electric water heater is a storage-tank water heater that uses one or two immersion resistance elements (typically 4,500 W at 240…
In older homes, the metal water service line entering the building was used as a grounding electrode for the electrical service. Since…
Electrolysis in plumbing is electrochemical corrosion driven by electric current at metal pipe joints — most often the copper-to-galvanized transition in pre-1970…
An Energy Star water heater is a unit certified by the EPA/DOE program that meets specific Uniform Energy Factor (UEF) thresholds. In…
Enzymatic drain cleaner is a slow-acting biological treatment using live bacteria (Bacillus or Pseudomonas strains) and enzymes to digest grease, hair, soap…
An escutcheon is a decorative chrome or metal trim plate that covers a wall or fixture opening — most commonly behind a…
An expansion tank is a small bladder tank installed on the cold supply at the water heater. It absorbs the volume of…
A faucet seat is the brass insert at the bottom of a compression-faucet body that the rubber stem washer presses against to…
Faucet spread is the horizontal distance between the centers of the two outermost mounting holes on a deck-mounted faucet. The three standard…
A Fernco coupling is a stainless-band-shielded rubber sleeve that joins two pipes — same or different outside diameter, same or different material…
The finish, rough-in, and underground inspections are the three standard stages of plumbing inspection on a permitted project. For the full breakdown…
A fire block is horizontal blocking installed in stud walls and at floor and ceiling junctions to limit the vertical spread of…
The first-hour rating (FHR) is the gallons of hot water a tank water heater can deliver in the first hour, starting from…
Flame impingement is what happens when a gas flame contacts a cold surface — a heat-exchanger fin, a heat shield, a pot…
A flame shield is a fireproof barrier — typically flexible fiberglass or ceramic-fiber cloth, or a folded sheet of metal — placed…
A flanged toilet plunger has a smaller cup (the flange) folded out from inside the larger cup. The flange seals the curved…
A flapper is the hinged rubber seal at the bottom of a toilet tank that sits on the flush-valve seat. Pressing the…
A flare fitting is a mechanical copper joint where the pipe end is flared outward — using a flaring tool — to…
A flared joint is a mechanical copper-tube connection: the tube end is belled into a 45-degree cone with a flaring tool, then…
Flexible copper tubing — also called soft or annealed copper — is copper sold in coils (typically 25, 50, 60, or 100…
A flexible gas connector is a yellow- or black-jacketed corrugated stainless-steel hose that links a fixed gas line (usually black iron in…
A flexible grooved coupling is a mechanical pipe coupling that joins two grooved-end pipes with a gasket and a bolted, two-piece housing.…
Float adjustment is the mechanism that sets the tank water level shutoff point on a toilet fill valve. On modern cup-float valves,…
A float switch is an electrical switch actuated by a float that rises and falls with water level. It's how a sump…
A float valve is a tank-fill valve closed by a rising float as the tank fills to a set level. Every residential…
A float-cup fill valve is the modern toilet fill valve — a vertical riser tube with a sliding cup-shaped float around it…
A floor drain is a trapped, grated drain set into a basement, laundry-room, or garage floor. Its job is to catch incidental…
Flow rate is the volume of water delivered per unit of time, measured in gallons per minute (GPM) in US plumbing. It's…
A flush valve is the outlet assembly at the bottom of a toilet tank: the seat the flapper rests on, the integrated…
Flux is a mildly acidic paste applied to a clean copper joint before soldering. It dissolves copper oxide that forms when copper…
Foam pipe insulation is slip-on closed-cell polyethylene or rubber foam tubing sized to common pipe sizes (1/2", 3/4", 1"). Pre-slit on one…
A foot valve is a one-way check valve installed at the bottom of a well-pump suction pipe, with a screen to keep…
A freeze-repair coupling (also called a slip coupling) is a stainless-braided push-fit splice with no internal stop, designed to bridge a burst-pipe…
Friction loss is the pressure drop along a pipe due to viscous drag at the wall and turbulence in the flow. It…
A frost cap is a foam-insulated cup that slips over an outdoor sillcock or hose bib to slow heat loss during freezing…
Frost closure is what happens when warm, moist air rising through a plumbing vent meets sub-freezing outside air at the roof. Condensation…
Frost depth is the depth at which the ground freezes hard enough to crack buried water pipes. Your water service line —…
A frost-proof sillcock is a long-stem outdoor faucet whose valve seat sits 6 to 24 inches inside the warm wall cavity. When…
Frozen pipes are water lines that have dropped below 32 °F long enough for the water inside to turn to ice. Because…
Galvanic corrosion happens when two dissimilar metals are joined in the presence of water (an electrolyte). The less-noble metal becomes the anode…
Galvanized iron pipe is steel pipe dipped in molten zinc for corrosion resistance. From roughly the 1900s through the early 1970s it…
A garbage disposal — called a disposer in trade and food waste grinder in code — is an under-sink electric grinder that…
A gas flexible connector is the short coated-stainless tubing — typically 12 to 60 inches — that runs between the rigid gas…
A gas leak is the uncontrolled escape of natural gas or propane from a piping system, fitting, or appliance. The added odorant…
A gas water heater is a storage-tank water heater fueled by natural gas or propane. A burner under the tank heats water,…
Gas-rated Teflon tape is a thicker yellow polytetrafluoroethylene (PTFE) tape applied to threaded fuel-gas pipe joints to seal and lubricate the assembly.…
A gate valve is a multi-turn shutoff valve with a flat or wedge-shaped disc — the "gate" — that lifts vertically out…
A GFCI (Ground Fault Circuit Interrupter) is an outlet or breaker that compares current flowing through hot and neutral conductors. If the…
Giardia is a single-celled parasite (protozoan) that causes severe diarrhea and is transmitted via the fecal-oral route from wild and domestic animal…
A globe valve is a multi-turn valve specifically designed for throttling — regulating flow rate, not just shutoff. The internal flow path…
A grandfather clause in plumbing means existing nonconforming work is generally allowed to remain in service as long as it was code-compliant…
A grease clog forms when cooking fats, oils, and grease (collectively, "FOG") cool inside the drain pipe and stick to the walls.…
A grease interceptor — sometimes called a grease trap when it's a small under-sink unit — is a tank that separates fats,…
Greenboard — moisture-resistant drywall, also called MR board — is not permitted as the tile substrate behind tubs and showers under modern…
Greywater is wastewater from showers, sinks, and washing machines (light greywater) or from kitchen sinks and dishwashers (dark greywater). Reusing it for…
A ground-source heat pump (GSHP), also called geothermal, exchanges heat with the soil through a buried fluid loop. Soil ten meters down…
Groundwater is the water that fills the porous layers — sand, gravel, fractured rock — beneath the earth's surface. It's recharged by…
A hacksaw is a manual fine-toothed saw with a tensioned, replaceable blade. In plumbing, it's the fallback when a tubing cutter can't…
A hair clog is a tangled mat of hair, soap scum, and body oil at the first restriction in a bathroom drain…
A hammer drill combines rotation with axial percussion — the bit hammers as it spins — to drill through brick, concrete, mortar,…
A hand shower is a showerhead on a flexible hose, mountable in a wall bracket or on a vertical slide bar that…
A handle puller is a small two- or three-jaw mechanical puller that grips under a faucet handle and presses a center screw…
Hard water has high calcium and magnesium content that leaves white scale on fixtures, kills appliances, and stops soap from lathering. Hardness…
A hard-water flapper (or chloramine-resistant flapper) is a premium toilet flapper made with rubber compounds — typically silicone or chemical-resistant elastomers —…
HDPE pipe is high-density polyethylene piping used for buried water-service mains, irrigation, gas distribution (medium-density variants), and industrial fluid transport. It's joined…
A heat pump is a heating and cooling system that moves heat from a low-temperature source — outside air, the ground, or…
A heat pump water heater (HPWH) is an electric storage tank that uses a small refrigeration loop on top of the tank…
Heat tape (also called heat cable or trace heating) is an electric resistance cable wrapped along a pipe to keep it above…
A hidden leak is a slow water-supply leak inside a wall, ceiling, slab, or crawl space — something you can't see but…
A high-efficiency toilet (HET) uses 1.28 gallons per flush or less — about 20% less than the federal 1.6-gpf standard. EPA WaterSense-labeled…
A high-water alarm on a septic system is a float-switch-triggered audible and visual alarm that activates when the liquid level in the…
A hinged shower door swings open on hinges (vs. sliding doors that ride in a track). The category splits three ways by…
A hose bib is the threaded outdoor faucet on the side of your house, designed to connect a garden hose. It connects…
A hose clamp is a stainless-steel band with a worm-screw mechanism that tightens uniformly around a flexible hose or PE pipe to…
A hose-bib vacuum breaker (HBVB) is a small atmospheric vacuum breaker designed to screw directly onto a hose-bib outlet (3/4-inch male hose…
A hot water dispenser is a small under-counter electric tank — typically 0.4 to 0.7 gallons — that heats water to about…
A house trap (or running trap, or building trap) is a U-shaped fitting installed near where the building drain leaves the house,…
A hub-and-spigot joint is the traditional cast-iron pipe joint where one pipe end is a bell-shaped hub and the next pipe's plain…
Hydro jetting uses a high-pressure water-jet head pulled through a drain or sewer line to cut grease, scale, and small roots, then…
Hydro jetting clears a sewer line with high-pressure water (1,500–4,000 psi residential) instead of a mechanical snake. It excels at grease, biofilm,…
A hydro-pneumatic tank is a pressurized water-and-air vessel paired with a pump (well pump or booster pump) that smooths pump cycling and…
Hydronic heating is whole-house heating that distributes heat using hot water (rarely steam in legacy installs) circulated through pipes to emitters —…
A hydrostatic pressure test fills new potable water piping with water, pressurizes it to a specified level (typically 1.5× working pressure or…
An ice-maker line is the thin (¼-inch OD) cold-water supply line that feeds a refrigerator's automatic ice maker and water dispenser. It…
An indirect-fired water heater is a storage tank with an internal heat-exchange coil that runs hot water (or steam) from a separate…
An inline filter is a strainer or cartridge filter installed in the supply line that removes sediment, particulates, or specific contaminants from…
The inside main shutoff is the single valve on your supply pipe just inside the building — downstream of the meter —…
An inspection chamber is a built-up access pit — usually concrete, brick, or precast — on a sewer or building-sewer pipe at…
The International Plumbing Code (IPC) is one of two dominant US plumbing codes, published by the International Code Council (ICC). It is…
Iron bacteria are non-pathogenic biofilm-forming microorganisms (Gallionella, Leptothrix, others) that consume dissolved iron in groundwater and produce a slimy, reddish-brown deposit. They're…
An iron filter removes dissolved iron and manganese from well water before they oxidize and stain fixtures. The modern standard is air-injection…
Iron pipe is umbrella vocabulary covering several distinct ferrous (iron-based) pipe materials: cast iron (CI) for drainage, galvanized iron (GI) for legacy…
An island vent is a venting workaround for fixtures — most commonly an island kitchen sink — where running a vent up…
A J-bend is the curved lower section of a P-trap — the U-shape that holds the water seal blocking sewer gas. A…
A jackhammer is a heavy demolition tool that breaks concrete with a chisel- or point-tipped striker driven by an electric motor or…
A jetted tub is a bathtub with multiple jets that recirculate water (water-jet "whirlpool") or introduce air bubbles (air-jet "air bath"). The…
A kitchen sink is the food-prep and wash-up fixture in a kitchen. Code defines it as a sanitary fixture with a 1½-inch…
A knock-out plug is the factory plug sealing the dishwasher inlet on a brand-new garbage disposer. If you're connecting a dishwasher to…
A laundry sink — also called a utility sink, slop sink, or laundry tub — is a deep free-standing basin used for…
A lavatory is the code and trade word for a bathroom sink — the small basin used for hand and face washing.…
Lead leaching is the release of lead from old plumbing — pre-1986 lead solder on copper joints, pre-1940 lead service lines, or…
Lead pipe — most often a lead service line (LSL) — is soft lead piping used widely for buried water-service connections in…
Lead solder — typically 50/50 tin-lead or 60/40 — was the standard for joining copper potable-water pipe in the US until 1986,…
Lead testing of drinking water is the lab or home-kit test that measures lead concentration at your tap. Pre-1986 homes (lead solder)…
A lead-and-oakum joint is the traditional seal on cast-iron hub-and-spigot drain pipe: tarred jute fiber (oakum) packed into the hub, with molten…
Lead-free solder is the tin-based filler metal mandated for potable-water copper joints in the US since the 1986 Safe Drinking Water Act.…
A leader or rainwater downpipe is the vertical pipe that carries gutter water from the roof to the ground. The dominant homeowner…
Leak detector solution is a chloride-free soap-based liquid sprayed or brushed on a pressurized gas joint to identify leaks visually. Gas escaping…
Legionella is an aquatic bacterium that proliferates in warm stagnant water (77–113°F) and is inhaled as aerosol from showers, humidifiers, and hot…
A licensed plumber is a tradesperson who has completed required apprenticeship hours and passed the WA L&I licensing exam to install, repair,…
Limescale is calcium-carbonate (and magnesium-carbonate) deposit from hard water — the white crust on showerheads, the spots on glassware, the chalky residue…
A linear trench drain is a long narrow drain — typically 24 to 60 inches — installed at the edge or center…
A low-flow showerhead delivers 2.0 gallons per minute or less, compared to the 2.5-gpm federal max. WaterSense-labeled models also have to pass…
LPG (liquefied petroleum gas) is the umbrella term for propane and butane — both heavier-than-air hydrocarbon fuels stored as liquid under pressure…
A macerator pump is a pump with integrated cutter blades that grinds solids in waste before pumping. Because the slurry no longer…
The main drain line is the homeowner's name for the building drain — the single horizontal drain pipe at the lowest level…
The main shut-off valve is the valve that stops all water entering your house. Most Washington homes have two: the inside main…
The main supply line is the indoor trunk pipe that carries water from the meter and inside main shutoff to the first…
The mains pressure range is the band of supply pressures a water utility delivers to your meter. In US homes it typically…
A manhole is a chamber sized for a person to enter, set on the public sewer main at junctions, direction changes, and…
A mechanic's lien (in Washington, formally a construction lien under RCW 60.04) is a legal claim a contractor, subcontractor, or supplier can…
A meter pit is the below-grade vault — concrete, plastic, or steel — that houses your water meter and adjacent valves on…
Minimum distribution pressure is the code-mandated floor — about 20 psi at the fixture under all flow conditions. Below that, fixtures don't…
A mixer faucet is any faucet that combines hot and cold water inside the body and delivers them through a single spout.…
Mold PPE is the safety gear required when cleaning mold yourself: a NIOSH-rated P100 (or at minimum N95) respirator, nitrile gloves, safety…
A nail plate is a thin galvanized-steel plate (16-gauge minimum) attached to wood framing where pipe or wire passes through, protecting the…
NEC bonding of metallic water piping is the National Electrical Code requirement (§250.104) that interior metal water pipes be electrically bonded to…
A needle valve is a globe-style valve with a long tapered needle that screws into a small precision seat. The geometry allows…
Negative grading is when the soil around your foundation slopes toward the house instead of away from it. Roof and surface runoff…
A nipple is a short length of pipe (under 12 inches) with male threads on both ends. It's used to extend a…
Nitrates are nitrogen compounds (NO3⁻) that enter groundwater from fertilizer, manure, septic-field discharge, and atmospheric deposition. EPA's drinking-water MCL is 10 mg/L…
No-hub cast iron is the modern form of cast-iron soil pipe — straight pipe ends without the bell-and-spigot hub of older CI.…
A no-hub coupling is a flexible coupling — an elastomer (neoprene or EPDM) sleeve inside a stainless-steel band with worm-drive screws —…
Non-potable water is water that isn't safe to drink without further treatment. The category includes raw surface water, untreated well water with…
Normal residential water pressure in the US is 40–80 psi static, with 50–60 psi treated as the sweet spot — high enough…
An O-ring is a round (toroidal) rubber ring that seats in a groove and seals between two mating parts under compression. Faucets…
Oakum is hemp or jute fiber treated with pitch (oil or tar), packed into the bell of a cast-iron hub-and-spigot drain joint…
Off-grid water sources for rural WA properties are typically wells (drilled or driven), springs, or rainwater catchment. Wells are the most reliable…
An offset toilet flange is a closet flange that shifts the drain centerline 1 to 2 inches laterally — used to recover…
Orangeburg pipe is bituminized fiber sewer pipe — layered wood-pulp fiber bonded with hot coal-tar pitch. Manufactured from 1945 to the early…
An overflow tube is the vertical pipe rising from the flush valve in a toilet tank, with its top about 1 inch…
A P-trap is the U-shaped fitting under every sink, lavatory, tub, shower, laundry, and floor drain in a modern home. The U…
A packing nut is the small nut, between the bonnet and the handle on a compression faucet, that compresses a packing washer…
A panel radiator is a pressed-steel hydronic emitter — typically two welded sheet-steel panels with internal water channels, mounted vertically on a…
A partially closed shutoff is a valve that's not fully open — most often the inside main shutoff, the curb stop, or…
PE pipe is polyethylene piping — most commonly the black flexible plastic used for buried potable water-service lines (PE-3408 / PE-4710 HDPE…
A pedestal sink is a wall-mounted bathroom lavatory with a freestanding floor column — the pedestal — that conceals the supply and…
Penetrating oil is a low-viscosity oil with solvents that wick into the threads of corroded fasteners and break the rust bond. PB…
Permit not required describes simple plumbing work that's exempt from the permit-and-inspection process. Most WA jurisdictions exempt fixture replacements in the same…
Permits and inspections are the two halves of the local building authority's enforcement process. A permit grants written authorization to do specific…
Personal protective equipment (PPE) is the gear that creates a barrier between you and a hazard while doing plumbing work. For typical…
PEX (cross-linked polyethylene) is the flexible thermoplastic supply tubing that has become the dominant new-construction and repipe material in Washington homes. Color-coded…
A PEX manifold is a central distribution block — usually brass, sometimes plastic or copper — with one supply inlet and multiple…
PEX-A is the most flexible class of PEX, manufactured by the Engel (peroxide) method during extrusion. It has the highest cross-link density…
PEX-B is PEX manufactured by a silane / moisture-cure cross-linking process performed after extrusion. Cross-link density is typically 65 to 70 percent…
A pH neutralizer (commonly a calcite filter) is a whole-house water-treatment tank that raises the pH of acidic water from below 7…
A phantom flush (or ghost flush) is a toilet that briefly refills on its own every few hours, despite no use. The…
A pilot light is the small standing flame at the burner of a gas water heater (or older gas furnace). It heats…
A pinhole leak is a tiny perforation through the wall of a copper water pipe, almost always caused by pitting corrosion. In…
A pipe bender produces a smooth radius bend in soft copper or aluminum tubing without kinking. Spring-type benders are the homeowner pick…
Pipe bursting is a trenchless replacement method: a bursting head is pulled through the existing pipe, fragmenting it outward into the surrounding…
A pipe cutter (also called a tubing cutter) is a tool that scores and snaps copper, CPVC, PEX, or steel pipe by…
A pipe fitting is any component that changes direction (elbow, return bend), branches a system (tee, wye, cross), changes size (reducer, bushing),…
A pipe hanger is any of several support devices used to suspend horizontal piping from joists, ceilings, or walls. The category includes…
Pipe joint compound (also called pipe dope) is a brushable paste applied to threaded pipe joints to seal the threads and lubricate…
A pipe patch is a temporary fix for a small leak — a rubber-gasketed repair clamp, an epoxy putty wrap, or a…
Pipe relining in its strict sense refers to spraying or centrifugally casting an epoxy resin coating inside an existing pipe to seal…
Pipe scale is calcium-carbonate (and sometimes magnesium-carbonate) mineral buildup on the inside walls of water-supply pipes. It's a hard-water phenomenon — Spokane…
Pipe schedule is a wall-thickness rating system for pipe. Higher schedule means thicker wall, higher pressure rating, and a smaller flow ID…
A pipe strap is a flat hanger strap that wraps over the pipe and is fastened on either side to framing —…
Pipe support spacing is the code-mandated maximum interval between pipe hangers, varying by pipe material. Spacing exists to prevent sagging, traps in…
A pipe wrench is a heavy steel wrench with a movable hardened-tooth jaw that self-tightens against threaded round pipe. The cammed pivot…
A pitless adapter is a sealed brass fitting installed through the side wall of a well casing, below the local frost line.…
Pitting corrosion is localized electrochemical attack on copper pipe walls — pinpoint-sized holes that grow deeper while the rest of the pipe…
Plastic pipe is umbrella vocabulary covering every polymer-based plumbing pipe — PVC, CPVC, ABS, PEX, PE/HDPE, polybutylene (legacy), and a handful of…
A plastic pipe ground bridge (more formally, a bonding jumper) is a copper conductor — typically #6 AWG for residential service —…
A plug is a male-threaded closure for the end of a pipe or fitting — the opposite of a cap, which is…
Plumber's grease is silicone-based, food-safe, NSF-rated lubricant used for O-rings, cartridge bodies, ball-valve internals, and threaded plumbing fittings. It won't harden, won't…
Plumber's putty is a soft, non-hardening, clay-like sealant rolled into a thin rope and bedded under sink-drain flanges, faucet bases, and pop-up…
A plumbing code governs the materials, sizing, joining methods, and installation of plumbing systems. Codes are adopted at state, county, or city…
A plumbing contractor is a licensed business entity that installs, repairs, and maintains plumbing systems — distinct from the individual plumber. In…
A homeowner plumbing inspection is a periodic systematic walkthrough of the home's plumbing — every visible pipe, fixture, valve, and supply line…
Polybutylene (PB) is a flexible plastic supply pipe widely installed in US homes from approximately 1978 to 1995. It's typically gray inside…
A pop-up drain is the standard bathroom-sink drain mechanism — a stopper at the drain opening connected by a lift-rod linkage to…
A pop-up sink stopper is the lever-actuated drain assembly in a bathroom lavatory. Pulling the lift rod up behind the faucet closes…
Potable water is water safe for drinking, cooking, and food prep — meeting regulatory standards for chemical, microbiological, and physical quality. In…
Power flushing is a high-flow chemical cleaning of a hydronic heating loop using a portable pump rig. Cleaner is circulated through the…
A powered anode rod is a plug-in tank-protection device that uses a small AC-DC transformer to drive a low DC current through…
A press fitting is a copper or stainless fitting with a pre-installed elastomeric O-ring inside a chamfered ring at each end. The…
A press-connect fitting is a copper, stainless, or carbon-steel fitting with an integral O-ring that's squeezed onto pipe by a battery-powered hydraulic…
A pressure arrestor is a small device installed near a quick-closing valve — a washing-machine fill solenoid, dishwasher inlet, icemaker line, or…
A pressure gauge is the homeowner's primary diagnostic tool for water-supply problems. The most common form is a hose-thread test gauge that…
The pressure gauge on a sealed hydronic boiler shows the fill pressure of the heating loop. A normal cold reading is around…
A pressure reducing valve (PRV) is a self-regulating valve that lowers incoming water pressure to a stable, safe downstream value regardless of…
A pressure relief valve is a safety valve that opens at a preset over-pressure threshold to vent excess to atmosphere through a…
A pressure switch is a spring-loaded electrical switch that turns a well pump or booster pump on at the cut-in (lower) pressure…
A pressure-assist toilet uses a sealed inner tank that compresses air as supply water enters; on flush, the compressed air rapidly expels…
A pressure-vacuum breaker (PVB) is a backflow assembly designed for continuous-pressure systems — primarily irrigation. It has a spring-loaded check valve and…
Propane (C3H8) is a hydrocarbon fuel — heavier than air, stored as liquid under pressure, used as gas — that serves as…
A propane torch is a handheld torch fed from a 14- or 16-ounce disposable cylinder, used to heat copper fittings to solder-melt…
PTFE tape (Teflon tape) is a thin polytetrafluoroethylene tape wrapped around the male threads of a pipe connection to seal and lubricate…
A pull-down kitchen faucet has a retractable spray head fed by a flexible hose. The spray head detaches from the spout for…
Cut-in pressure is the lower threshold at which the pressure switch energizes a well pump or booster pump; cut-out pressure is the…
A push-connect fitting seals a pipe with internal stainless-steel teeth (the "collet") that grip the pipe and an EPDM O-ring that seals…
A push-fit fitting is a tool-free fitting with internal stainless-steel teeth (the grip ring) that bite into the pipe and an EPDM…
PVC pipe (rigid polyvinyl chloride) is the white or off-white thermoplastic used for cold-water supply, drainage / waste / vent (DWV), and…
PVC primer is a solvent (typically tetrahydrofuran or MEK) tinted purple, applied to PVC pipe and fitting surfaces before solvent cement. It…
PVC Schedule 40 (DWV) is the white rigid plastic pipe used for most modern residential drain, waste, and vent piping. It's lightweight,…
A quarter-turn valve is the umbrella term for any valve operated by a 90-degree lever motion — primarily ball valves and butterfly…
Radon in water is dissolved radon gas — a radioactive decay product of uranium found in groundwater drawn from uranium-bearing rock formations.…
A rain shower is an oversized showerhead — typically 8 to 16 inches across — mounted on the ceiling or via a…
Rainwater harvesting captures roof runoff for landscape irrigation, garden use, or non-potable supply. WA allows it without a water right under the…
Rainwater plumbing is the umbrella term for the system that moves rainwater from your roof to the ground and away from your…
A recessed laundry box is the wall-mounted plastic or metal enclosure behind a washing machine that holds the hot and cold supply…
A reciprocating saw is a power saw with a long replaceable blade that moves back and forth at high speed. It cuts…
The recovery rate of a water heater is the gallons (or liters) per hour it can heat from cold inlet temperature to…
A reducer is a fitting that joins two pipes of different sizes. Available concentric (both pipes share the same centerline) or eccentric…
A reducing bushing is a fitting that inserts into a larger female fitting (tee, coupling, valve) and provides a smaller female outlet…
A refill valve (or fill valve) is the toilet tank's inlet valve — the modern replacement for the older brass ballcock. It…
A regeneration cycle is the brine-rinse process that resets a water softener's resin after it's saturated with calcium and magnesium. Stages: backwash,…
A cast-iron repair flange is a replacement closet flange designed to fit into a cast-iron drain riser whose original flange has corroded…
A repipe is the systematic replacement of a building's water-supply piping — cold and hot distribution — when the existing material has…
A resistance heating element is a threaded or flanged immersion electrode that converts electricity to heat in an electric water heater. Standard…
Reverse osmosis (RO) is the drinking-water filtration method that pushes water through a semi-permeable membrane to remove 95–99% of dissolved solids, including…
A right-angle drill has its chuck mounted at 90 degrees to the motor body, so it fits between floor joists or wall…
Rigid copper tubing is hard-drawn copper sold in straight 10- and 20-foot sticks. It's approved for residential potable water in all major…
Rim holes (or rim jets) are the small diagonal holes drilled around the underside of a toilet bowl rim. They direct flush…
A riser clamp is a two-piece (top and bottom half) clamp that wraps around a vertical pipe and rests on the framing…
A roof vent is the visible top of your plumbing vent stack — a 2- to 4-inch pipe extending 6 to 12…
Rough-in is the construction phase where supply lines, drain lines, vents, and gas lines are installed in framed walls and floors before…
Rough-in dimensions are the specific measurements (typically distance from a finished wall to the center of a drain or supply stub-out) that…
Rough-in inspection stages are the three (sometimes four) standard inspection points during a permitted plumbing project. Inspectors visit at "open" stages —…
The RPZ (Reduced-Pressure Zone) backflow preventer is the highest-protection mechanical backflow assembly. It uses two independent spring-loaded check valves in series, with…
An S-trap is a banned trap geometry that exits vertically downward instead of horizontally. The vertical drop creates a continuous water column…
A saddle valve is a clamp-on valve with a sharp piercing tip that pierces a live water line when the homeowner turns…
Saltwater intrusion is the migration of seawater inland into a coastal freshwater aquifer, usually triggered by over-pumping that drops the freshwater head…
Sand filter and mound systems are engineered alternatives to standard in-ground drainfields, used where the soil can't take effluent the conventional way:…
A sanitary tee is a drainage-tee fitting with a curved sweep at the side branch entry, used to bring a horizontal branch…
The scald exposure curve is the reference table relating hot-water temperature to the contact time required to produce a full-thickness (third-degree) burn…
A scald-control faucet is a single-handle tub or shower faucet with a built-in pressure-balance spool, a thermostatic cartridge, or both — preventing…
Scalding is a thermal burn from hot water or steam. The severity depends on both temperature and contact time. The standard residential…
Scale or mineral deposits are the visible white deposits left behind by hard water — at faucets, in kettles, on glassware, around…
A Schrader valve is the standard tire-style air valve used as the air-charge port on accumulators (well pressure tanks) and expansion tanks.…
A working septic tank stratifies into three layers. The scum layer floats at the top — fats, oils, grease, soap residue, undigested…
A sealed (pressurised) heating system is a modern closed hydronic loop with no atmospheric vent. The system is filled to about 1…
A seamless aluminum gutter is a continuous gutter run extruded on-site by a contractor's roll-forming machine, eliminating the joints (and leak points)…
A seat wrench is a stepped tool with multiple hex and square ends, sized to fit the recessed sockets in a replaceable…
Seattle tap water comes from two protected upland Cascade watersheds — the Cedar River and the South Fork Tolt River — managed…
Second fix (UK term; "trim-out" or "finish" in US) is the construction phase where the visible plumbing fixtures — toilets, faucets, sinks,…
A sediment filter is the first stage in most water-treatment systems — a cartridge or backwashable screen that catches sand, silt, and…
Sediment in a water heater is the layer of minerals, rust, and debris that settles at the bottom of the tank over…
A sediment trap (drip leg) is a short vertical capped nipple in the gas line just upstream of every gas appliance's control…
A seismic anchor bolt is the hardware that fastens plumbing equipment — water heater pads, pump bases, tanks — to the slab…
A seismic brace is a rigid strut or steel-cable assembly that ties horizontal pipes, ducts, and suspended equipment to the building structure…
Seismic protection in plumbing is the layered set of bracing, anchoring, and flexible-connection strategies that keep plumbing systems functional during ground shaking.…
Seismic strapping is the pair of heavy-gauge metal straps required on every WA water heater to keep it from tipping during an…
Self-siphonage is the trap-seal-loss mechanism in which a fixture's own discharge creates a full-flow water column in its drain that pulls the…
Septic pumping is the periodic removal of accumulated sludge and scum from a septic tank by a vacuum-truck service. Skipping it is…
The standard WA recommendation for septic tank pumping is every 3 to 5 years, with the exact interval depending on tank size,…
A septic system (officially an on-site sewage system or OSS in Washington) is the private wastewater treatment installation found on rural and…
A septic system inspection is a certified review of the tank, baffles, effluent filter, distribution box, drainfield surface, and alarm. In Washington,…
Septic-incompatible substances are household products and waste that either kill the anaerobic bacteria a septic system depends on, accumulate as undigested sludge,…
A water service line is the underground pipe that brings water from the public main (or a private well) to your house.…
A sewage backup is wastewater flowing the wrong direction — out of a fixture, floor drain, or cleanout instead of into the…
A sewage ejector pump lifts wastewater from below-grade fixtures — basement bathrooms, daylight-basement laundries, ADUs below the public sewer level — up…
A sewer camera (or sewer scope) is a flexible push-rod with a small high-resolution camera at the tip and a screen at…
A sewer camera inspection — usually called a sewer scope in PNW real estate — uses a self-leveling video camera on a…
Sewer gas is the mixed gas inside your home's drains and the public sewer beyond — primarily methane, hydrogen sulfide (the rotten-egg…
Sewer lateral root intrusion is the technical name for tree roots growing into a residential side sewer through joint imperfections in clay…
A sewer machine is a powered drum auger with a 3/8 to 5/8-inch cable, a foot-pedal "dead-man" switch, and interchangeable cutter heads.…
Shock chlorination is a one-time high-dose chlorination of a well or piping system to kill bacterial contamination after a coliform-positive test, well…
A shower arm is the L-shaped chrome (or matte / colored) pipe that extends from the wall and supports the showerhead. It…
A shower base (also called a shower pan, receptor, or tray) is the bottom of a stand-up shower stall — collects water…
A shower curb is the raised lip at the entrance of a stand-up shower stall — keeps water inside the shower. Standard…
A shower enclosure kit is a prefab shower with three wall panels and (sometimes) a door and base, supplied as a packaged…
A shower head is the spraying fixture at the end of a shower arm. It mixes water flow into a shaped pattern…
A shower pan leak test is the standard pre-tile verification procedure for a custom shower pan (mortar or foam). Plug the drain,…
A shut-off valve is any valve that isolates a portion of the plumbing system from the supply — manually operated, two-way (on…
A side sewer is the underground pipe that carries all of a home's wastewater out to the public sewer main. Engineers and…
A sink cutout is the opening in a counter that a sink drops into (drop-in / self-rimming) or hangs below (undermount). For…
Siphoning action (or siphonic action) is the basic physics by which an unbroken column of water pulls more water along behind it…
A sliding shower door has two glass panels riding on top and bottom tracks; one slides past the other (bypass) to enter…
Slip lining is a trenchless rehabilitation method that inserts a smaller-diameter new pipe — typically continuous HDPE — inside an existing host…
A slip nut is a threaded ring (1¼-inch lavatory or 1½-inch kitchen) that compresses a beveled nylon or rubber washer to seal…
A smart thermostat is a Wi-Fi-connected programmable thermostat with scheduling, occupancy detection (geofencing), and learning algorithms. Common brands: Nest, ecobee, Honeywell T9.…
A smoke test pushes visible smoke into a sealed-off DWV (drain, waste, vent) system or sewer line. Visible smoke escaping at any…
A snap cutter is a chain wrapped with small cutting wheels that goes around a cast-iron pipe; ratcheting the handle increases tension…
Soft acidic water has low mineral content (soft) AND low pH (acidic). The combination is unusually aggressive on copper pipes and lead…
Softener salt is the regenerant a water softener uses to recharge its resin. The three common forms are rock salt (cheapest, leaves…
A soil pipe is the drain pipe that specifically carries discharge from toilets, urinals, and bidets — the soil/excreta line. The vertical…
A solar water heater is a system that uses roof-mounted collectors to capture solar energy and transfer it to a hot water…
Solder wire is the filler metal supplied as a coiled wire on a spool, melted by a torch into a fluxed copper…
A solenoid valve is an electrically operated valve. An electromagnetic coil pulls a plunger or pilot diaphragm when energized, opening or closing…
Solvent cement welding is the chemical-fusion joining method for plastic pipe (PVC, CPVC, ABS). The primer (where required) and cement contain solvents…
Spokane tap water comes from the Spokane Valley–Rathdrum Prairie (SVRP) aquifer, a 370-square-mile sole-source aquifer designated by the EPA in 1978. The…
A smart sprinkler controller is a Wi-Fi irrigation timer that adjusts watering based on real weather and soil data instead of running…
A SPU side sewer permit is the authorization issued by Seattle Public Utilities (SPU) for any work connecting, replacing, or repairing a…
A spud nut is the large nut on the underside of a toilet tank that secures the flush-valve assembly to the porcelain.…
A spud wrench is a wide-jaw, flat wrench used on the large slip nuts that connect a toilet tank to its bowl,…
A stack is any vertical drain or vent pipe running through a building. Drainage stacks carry water and air downward; vent stacks…
A stack vent is the extension of a drainage stack above the highest connected horizontal drainage branch — the part of the…
Stagnation is long sit-time water in tanks, dead-leg pipes, or unused fixtures. As the chlorine or chloramine residual that fresh utility water…
A laundry standpipe is a 2-inch vertical drain pipe with an integral P-trap at its base, terminating in an open-top receptor that…
Static water pressure is the supply pressure when no fixtures are flowing — the resting pressure in the line. It's what a…
A static water pressure test is the homeowner's standard supply diagnostic: screw a hose-bib pressure gauge onto an exterior hose bib, close…
A steam shower is a sealed shower stall integrated with an electric steam generator that produces low-pressure steam at about 100°C. A…
Steel pipe is iron alloy with controlled carbon content (typically under 0.3%) formed into seamless or welded tube. In residential plumbing, "steel…
A stop-and-waste valve is a globe- or ball-style shutoff with a small downstream "waste" port — a screw or plug — that…
A storm drain carries rainwater, surface runoff, and clear water from a property to the public storm sewer or directly to a…
Stormwater drainage is how rainwater and surface runoff move from your property toward a discharge point — natural ground, a drywell, the…
A strap wrench uses a rubber or fabric strap that wraps around a chrome or finished part, with a handle that clamps…
A stub-out is a short pipe segment projecting through a wall or floor into a fixture rough-in, capped or terminated for later…
A sump pit is the lined basin sunk into the lowest point of a basement floor that collects groundwater seeping in through…
A sump pump is a submersible or pedestal-mounted electric pump installed in a sump pit at the lowest point of a basement.…
A sump pump check valve is a one-way valve on the pump's discharge pipe, installed just above the pit. When the pump…
Sump pump sizing is the process of matching a pump's capacity to the actual water inflow at the actual lift height in…
A surface water source is a river, lake, or reservoir that feeds a public water system. Most of Washington's largest municipal utilities…
A sweat fitting is a copper or brass fitting joined to copper pipe by capillary action of melted solder. Process: clean both…
Sweating a joint is the standard residential method for joining copper pipe and fittings. The pipe is cleaned, fluxed, and assembled with…
A swing check valve has a hinged disc that swings open under forward flow and closes under reverse flow. It's a low-pressure-drop,…
A T&P relief valve (temperature and pressure relief valve) is the required safety valve threaded into the top or upper side of…
The T&P test lever is the small metal lever on top of the temperature and pressure relief valve. Lifting it manually opens…
Tacoma tap water comes primarily from the Green River watershed (~95% of supply), supplemented by groundwater wells. It's filtered at the Green…
A tailpiece is the straight vertical drain pipe between a sink and its P-trap. It hangs from the basket strainer (kitchen) or…
Tank bolts are the two or three brass bolts that secure a tank to a bowl on a two-piece toilet. Each passes…
A tank gasket (or tank-to-bowl gasket) is the large rubber doughnut between the bottom of a two-piece toilet's tank (around the flush-valve…
Tank water condensation is moisture that forms on the outside of a toilet tank when warm, humid bathroom air meets the cold…
The tank-set temperature is the thermostat setpoint on your water heater. WA requires new heaters to be preset at 120°F. That setting…
Tanking is the process of waterproofing a wet-room or curbless shower by applying a continuous liquid-membrane (or sheet-membrane) layer over the floor,…
A tankless water heater is a heater that produces hot water on demand without storage. Cold water flows through a heat exchanger…
A tee is a 90-degree branching fitting with three openings — two on the run (in-line ends) and one perpendicular branch. Available…
Tempered glass is glass that's been heat-treated to roughly four times the strength of standard annealed glass. When it does break, it…
Tempered water is hot and cold water mechanically blended to a safe handwashing or bathing temperature, typically 100–110°F. The blend happens automatically…
A thermocouple is the small pencil-shaped sensor in a standing-pilot gas water heater that generates roughly 25 millivolts when its tip is…
A water heater thermostat is a bi-metal switch that senses tank temperature and turns the heating element on or off. Two-element electric…
A thermostatic mixing valve (TMV) uses a temperature-sensing cartridge to blend hot and cold water and hold a precise outlet setpoint. The…
A thermostatic radiator valve (TRV) is a self-actuating valve on the supply side of a radiator that throttles flow as room air…
Thinset mortar is the cement-based adhesive for setting tile in showers, tubs, and floors. Modern thinset is "modified" with a polymer additive…
A three-way diverter valve is the manual or automatic switch in a greywater system that routes wastewater either to the reuse path…
Tiny-home plumbing is the compact plumbing system in an Accessory Dwelling Unit (ADU), Detached ADU (DADU), or stand-alone tiny home. On a…
A toilet (water closet, WC) is the gravity-flush sanitary fixture that drains into the building's DWV system through a closet flange and…
The toilet dye test drops food coloring or a dye tablet into a toilet tank and waits 15 minutes. If the dye…
Toilet rough-in is the horizontal distance from the finished wall behind the toilet to the center of the closet flange (the drain)…
A toilet shim is a thin plastic wedge inserted between the toilet base and the floor to level a wobbly toilet. After…
A torque wrench is a wrench that signals (audible click, beam deflection, or digital readout) when a specified tightening force is reached.…
A touchless faucet activates by motion sensor (infrared) or capacitance touch (light contact anywhere on the faucet body) instead of by handle…
A towel warmer is a chromed steel ladder or grid mounted in a bathroom that doubles as a hydronic emitter or a…
A TPR discharge tube is the pipe that runs from the side outlet of a water heater's T&P relief valve down to…
A trap is a bent drain fitting that holds a small column of water — the trap seal — to block sewer…
A trap arm is the segment of horizontal drain pipe between the top of a fixture's trap (the trap weir) and the…
Trap arm length is the maximum allowable horizontal distance between a fixture's trap weir and the vent connection that protects it. Run…
Trap evaporation is the slow drying of a fixture's trap seal when the fixture isn't used. A standard 2-inch trap evaporates roughly…
The trap seal is the column of standing water inside a fixture's trap that blocks sewer gas from rising into the home.…
Trap seal loss is the umbrella term for every mechanism by which the standing water that blocks sewer gas is removed from…
Trenchless sewer replacement is the family of pipe-repair methods that avoid full open-trench excavation by working through small entry and exit pits.…
A tripwaste mechanism is the in-tub system that opens and closes the tub drain via a small lever on the overflow plate.…
A tub spout delivers water to the bathtub. Two install styles cover almost all residential spouts: threaded (interior threads onto a 1/2-inch…
Tub-and-tile caulk is 100% silicone (or siliconized acrylic) sealant rated for prolonged water exposure and mildew resistance. It seals the tub-to-tile joint…
A tub-shower combo is a tub fitted with both a tub spout (for filling) and a shower head (for showering), all served…
Tuberculation is the buildup of nodular rust deposits ("tubercles") on the inside walls of iron and galvanized-iron supply pipe. Over decades, the…
A tubing cutter is the small-format wheel cutter for copper, CPVC, PEX, and brass tubing. It is the same tool as a…
Type K copper is the heaviest-wall residential copper grade, identified by green lettering on the pipe. It's the standard buried water-service material…
Type L copper is the medium-wall residential copper grade, identified by blue lettering on the pipe. Approved for residential and commercial above-ground…
Type M copper is the thinnest-wall residential code-approved copper grade, identified by red lettering on the pipe. Approved for residential supply above-ground…
UEF stands for Uniform Energy Factor — the federal Department of Energy efficiency rating that has appeared on every new water heater…
Underfloor heating (UFH) circulates warm water at 95–125°F through PEX pipework laid in a concrete slab or under suspended timber floors, heating…
The Uniform Plumbing Code (UPC) is one of two dominant US plumbing codes, published by IAPMO (International Association of Plumbing and Mechanical…
A union is a three-piece serviceable fitting that lets a joint be unscrewed for service or replacement without cutting the pipe. Two…
A Universal Design bathroom is built around a design philosophy that creates spaces usable by people of all ages and abilities, without…
An up-flush system is a packaged tank-and-macerator-pump unit installed behind a toilet (or in a small adjacent enclosure) that lets a basement…
A utility knife is a handheld retractable-blade knife used for cutting drywall, scoring caulk, deburring PEX or CPVC, opening fittings bags, scoring…
UV disinfection is a chamber with a UV lamp that inactivates bacteria, viruses, and protozoa in water flowing through it. It's a…
A vacuum breaker is the umbrella term for any device that admits air into a piping section to break a siphon when…
A vanity cabinet is the closed base cabinet that supports a bathroom sink and counter and provides storage below. Stock widths are…
A vent cowl (or vent cap, rain cap) is the fitting on top of a plumbing vent stack at the roof. It…
A vent obstruction is anything blocking or narrowing the air path through a plumbing vent stack. The result cascades through the whole…
A vent pipe is a drainage-system pipe that carries air, not water. Without venting, a draining fixture creates suction inside the pipes…
A vessel sink is a sculptural bowl that sits on top of a counter or vanity, with the drain dropping straight through…
WAC 246-274 is the WA Department of Health rule governing greywater reuse for subsurface irrigation. It permits homeowners to redirect greywater (shower,…
WAC 246-290 is the WA Department of Health rule governing Group A public water systems — utilities serving 15+ connections or 25+…
A wall-hung lavatory is a bathroom sink mounted directly to the wall with no pedestal or leg beneath. A steel hanger bracket…
The Washington L&I plumbing license is the state-level certification required for anyone doing plumbing work in WA. The Department of Labor &…
The Washington plumbing apprenticeship is the state-administered path to becoming a licensed plumber. Trainees register with WA L&I as plumber trainees, work…
Water hammer is the bang you hear when a fast-closing valve abruptly stops moving water — washing machine, dishwasher, ice maker, single-handle…
A water hammer arrestor is a sealed bladder device that absorbs the pressure spike from a fast-closing valve. Unlike legacy air chambers,…
A water heater insulation blanket is an aftermarket fiberglass-and-vinyl wrap secured around a tank water heater to reduce standby heat loss. Adds…
A water heater leak is any visible water at or below the heater. The diagnosis is everything: a leak from the T&P…
A water heater permit authorizes the replacement or new install of a water heater and brings an inspector to verify code-required items:…
Water heater replacement is the most common large plumbing job in WA homes. State code requires a permit, two seismic straps, a…
A water heater warranty is the manufacturer's coverage of tank rust-through and major component failures, typically running 6, 9, or 12 years.…
The water meter is the utility-installed device that measures every gallon of water entering your house. It sits at the property line…
The water meter leak test uses your utility's water meter as a leak detector. Shut off every fixture, watch the meter or…
A water softener is a whole-house appliance that removes calcium and magnesium from hard water through ion exchange — replacing the hardness…
The water supply system is the network that delivers potable water from its source — a public main or private well —…
The water table is the depth below ground at which the soil and rock become fully saturated with water — the top…
A waterlogged pressure tank has lost the air cushion that keeps a well pump from cycling on every fixture use. The classic…
The WaterSense label is a voluntary EPA certification (launched 2007) for water-efficient toilets, faucets, showerheads, urinals, and irrigation products. Certified products meet…
A wax ring is the doughnut-shaped beeswax (sometimes synthetic) seal compressed between the toilet bowl horn and the closet flange. When you…
A wax-free seal is a foam-and-rubber drop-in alternative to a traditional wax ring. It includes a flexible polymer gasket and a built-in…
A well cap is the sanitary seal at the top of a well casing. It's vermin-proof, watertight to surface water, and includes…
A well casing is the steel or PVC liner installed inside the borehole. It serves two jobs: structural support to keep the…
A well pump moves water from a private well bore up to the building's pressure tank. Two main types: submersible pumps run…
Well water is groundwater drawn from a private well — untreated by any utility before it reaches the tap. If your home…
Annual well water testing is the WA Department of Health-recommended routine for every private well: a yearly mail-in test for total coliform…
A wet room is a bathroom where the entire floor and all walls are waterproofed (tanked). The shower has no curb or…
A wet vent is a drain pipe that simultaneously serves as the vent for an upstream fixture. It's the most economical way…
A wet wall is an interior wall framed with 2x6 lumber (instead of standard 2x4) to provide enough depth for plumbing supply,…
A whirlpool tub — also called a jetted tub or hydromassage tub — is a bathtub with a built-in pump and motor…
The whole-house shutoff is the single valve that isolates the entire interior plumbing system from the incoming service line. Most WA homes…
A whole-house water filter is point-of-entry (POE) treatment that affects every fixture in the house, not just the kitchen sink. The right…
A winterization blow-out is the compressed-air procedure that pushes residual water out of an outdoor irrigation system, the backflow assembly, and connected…
A workmanship warranty is the plumber's written guarantee on their labor — typically 30 days to 1 year on service work, 1…
WSEC (Washington State Energy Code) is WA's adoption of and amendments to the IECC (International Energy Conservation Code). WSEC governs water heater…
A wye is a 45-degree branching fitting — three openings, with the branch joining the run at 45° rather than 90°. The…
A yard hydrant is a free-standing freeze-proof outdoor spigot, fed by a buried supply line, with the actual valve mechanism sitting below…