Bathroom Glossary

Acrylic Bath

A bath made from sheets of acrylic plastic, reinforced underneath with fibreglass (GRP). Acrylic is lightweight, retains heat well, and is the most common bath material in UK homes. Available in a wide range of shapes and sizes.

Aerator

A small mesh fitting screwed into the end of a tap spout that mixes air into the water flow. It softens the stream, reduces splashing, and lowers water consumption without reducing pressure at the spout.

Anti-Siphon Valve

A valve that prevents water from being drawn backwards into the supply pipework. Required in certain installations to protect against contamination of the mains water supply.

Back-to-Wall Toilet

A toilet where the cistern is hidden inside a wall or furniture unit, leaving only the pan visible. Creates a clean, minimal look and makes the bathroom easier to clean. The flush is usually operated via a plate on the wall.

Basin Mixer

A tap that blends hot and cold water before delivering it through a single spout. Controlled by one lever or two separate handles. The standard tap type for most modern bathrooms.

Bath Filler

A tap or valve specifically designed to fill a bath at a higher flow rate than a standard basin tap. Often combined with a hand shower as a bath/shower mixer.

Bath Panel

A removable panel that covers the side or end of a built-in bath, concealing the plumbing and bath frame underneath. Available in a range of finishes to coordinate with bathroom furniture.

Bi-fold Shower Door

A shower door that folds in on itself when opened, similar to an accordion. Useful in bathrooms where there is not enough clearance for an outward-swinging door.

Bidet

A low basin or attachment designed for personal hygiene, used after using the toilet. Can be a freestanding ceramic fixture or a seat that fits on an existing toilet pan.

Bottle Trap

A curved pipe fitted beneath a basin that holds a small amount of water to prevent drain gases from entering the room. Named for its bottle-like shape. Used where a P-trap would be too deep.

Brassware

A collective term for bathroom fittings that use brass in their construction, including taps, shower mixers, and accessories. Brass is used for its durability and corrosion resistance, regardless of the external finish.

BTU (British Thermal Unit)

The unit used to measure the heat output of a radiator or heated towel rail. A higher BTU rating means more heat output. Used to match a radiator to the size and heat requirement of a room.

Cast Iron Bath

A heavy, durable bath made from iron and coated with porcelain enamel. Retains heat better than any other bath material. Strongly associated with classic roll top and freestanding designs.

Ceramic Disc

A valve mechanism used in modern taps, using two ceramic discs instead of a rubber washer to control water flow. Ceramic disc taps are highly durable, drip-resistant, and operate smoothly with a quarter turn.

Cistern

The water storage tank that supplies a toilet flush. Water fills the cistern after each flush and is released into the pan when the flush is activated. Can be visible (close-coupled), concealed (back-to-wall), or hidden inside the wall (wall-hung).

Close-Coupled Toilet

A toilet where the cistern sits directly on top of the pan. The most common toilet configuration in UK homes. Straightforward to install and available in a wide range of styles.

Combination Boiler (Combi)

A boiler that provides both central heating and instant hot water on demand, without needing a separate hot water cylinder or cold water storage tank. The most common boiler type in UK homes.

Concealed Cistern

A cistern built into a wall or furniture unit, used with back-to-wall or wall-hung toilets. Only the flush plate is visible on the wall. A slim frame (carrier frame) holds the cistern and pan in place inside the wall.

Corner Basin

A basin designed to fit into a 90-degree corner, making the most of otherwise wasted space. Often used in compact cloakrooms where wall space is limited.

Countertop Basin

A basin that sits on top of a vanity unit or worktop surface. A popular choice for contemporary bathrooms, creating a furniture-like look. Requires a solid worktop that can support the weight.

Deck Mounted

Describes taps or fittings that are mounted on the rim of a bath or on a worktop surface, as opposed to being fixed to the wall. Bath filler taps are commonly deck mounted.

Digital Shower

A shower system where temperature and flow are controlled electronically via a remote panel or app, rather than by turning a valve directly. Allows precise, consistent settings and can be pre-programmed.

Diverter Valve

A valve that switches water flow between two outlets, for example between a bath filler and an overhead shower. Only one outlet runs at a time.

Dual Flush

A toilet flush system offering two options: a full flush (typically around 6 litres) and a reduced flush (around 4 litres). The smaller flush is sufficient for liquid waste, saving water with everyday use.

Enamel

A hard, glass-like coating applied to cast iron or steel baths. Creates a smooth, glossy, stain-resistant surface. More durable than acrylic but can chip if struck by a hard object.

Escutcheon

A decorative cover plate fitted around a tap, valve, or pipe where it meets the wall or surface. Covers any gaps or rough edges in the wall for a neat finish.

Flow Rate

The volume of water delivered per minute by a tap or showerhead, measured in litres per minute (L/min). Flow rate is affected by water pressure. Most shower products specify a minimum flow rate requirement.

Frameless Enclosure

A shower enclosure where the glass panels are supported by minimal metal fixings rather than a full surrounding frame. Creates a sleek, open look. Requires thicker glass (typically 8mm or 10mm) than framed enclosures.

Freestanding Bath

A bath that stands independently without being built into a surround or fixed against a wall. Can in theory be positioned anywhere in the room. Includes roll top, slipper, and modern oval designs.

Full-Pedestal Basin

A basin supported by a full-height column (pedestal) running from the basin to the floor. The pedestal conceals waste and supply pipes. A classic, practical choice that suits traditional and contemporary bathrooms.

Gravity-Fed System

A hot water system where water is stored in a tank in the loft and flows by gravity. Generally lower pressure than a mains-fed system. Power showers and certain thermostatic valves require a minimum pressure that gravity-fed systems may not always provide.

GRP (Glass Reinforced Polyester)

A fibreglass material bonded to the underside of acrylic baths and shower trays during manufacture. GRP adds rigidity and structural strength without significantly increasing weight.

Handset

The handheld showerhead attached to a hose. Can be used in hand or slotted into a holder on a riser rail. Most shower systems include a handset as standard.

Heated Towel Rail

A radiator designed to hang towels, keeping them warm and dry. Available in central heating, electric, or dual-fuel versions. Also contributes to room heating. Output is measured in BTUs or watts.

Hinged Shower Door

A shower door that opens outward on fixed side hinges, like a standard door. Provides a wide opening but requires clearance space in front. Common in larger enclosures and walk-in configurations.

Isolation Valve

A small valve fitted on the supply pipework to a tap, toilet, or other fitting that can be turned to shut off water to that fixture alone, without cutting supply to the rest of the home. Usually slotted for a flathead screwdriver.

Joist

The horizontal structural timbers in a floor that carry the weight of the room above. Relevant when installing heavy baths — cast iron freestanding baths in particular may need additional joist reinforcement. Worth checking with a builder before committing to a very heavy bath.

Kilowatt (kW)

The unit of power used to rate electric showers, heated towel rails, and underfloor heating elements. A higher kW rating means more heat output or faster water heating. Electric showers typically range from 8.5kW to 10.8kW — a higher rating delivers better performance at lower water pressures.

Knurled

The textured, ridged grip pattern machined onto nuts and connectors — most commonly seen on shower hose connections. Knurling allows hand-tightening to a firm seal without needing tools.

Low-Profile Shower Tray

A very shallow shower tray, typically 25 to 40mm high, designed to sit almost flush with the floor. Gives an easy-access, level-entry look. Some require a recessed floor or raised deck to accommodate the waste pipe.

Macerator

A pump unit that grinds toilet waste and pumps it through a narrow pipe (typically 22mm) to the soil stack. Used when a toilet or basin needs to be installed away from the main drainage run, for example in a loft conversion or cellar.

Mixer Tap

A tap that blends hot and cold water and delivers it through a single spout. Controlled by one lever or two separate handles. Suitable for both high and low pressure systems depending on the model.

Monobloc Tap

A mixer tap designed to fit through a single hole in the basin or bath. The most common tap type in modern bathrooms. Handles and spout are all part of one unit.

No-Hole Basin

A basin supplied without any pre-drilled tap holes. Gives you the freedom to choose wall-mounted taps or to drill your own holes to suit a specific tap configuration. Common with countertop and vessel basins.

Non-Return Valve

A valve that allows water to flow in one direction only, automatically closing to prevent backflow into the supply pipework. Required by water regulations in installations where there is a risk of contaminated water being drawn back into the mains. Also called a check valve.

Offset Quadrant Enclosure

A shower enclosure with a curved front and unequal side lengths, designed to sit in a corner over a rectangular shower tray. Combines the corner-fitting of a quadrant with more usable internal space.

Overflow

A hole or slot near the top of a basin or bath that prevents water from overflowing if a tap is left running. Water drains away through the overflow into the waste pipework.

P-Trap

A section of curved waste pipe beneath a basin or bath shaped like the letter P. The curve holds a small amount of water that acts as a seal, preventing drain gases from entering the room.

Pedestal

A floor-standing column that supports a washbasin and conceals the waste and supply pipes inside it. Available in full and semi versions.

Pillar Taps

Separate hot and cold taps with a tall, upright body, each fitting into its own hole. A traditional style commonly found on older baths and two-tap basins.

Pivot Shower Door

A shower door that rotates on pivot points at the top and bottom of the frame, rather than on side hinges. Opens both inward and outward, making entry easy. Requires clearance space outside the enclosure.

Pop-Up Waste

A basin waste controlled by a push button or integrated rod mechanism in the tap, allowing the plug to be raised and lowered without touching it. Convenient but requires occasional cleaning to prevent hair build-up.

Power Shower

A shower with a built-in electric pump that boosts water pressure, making it suitable for gravity-fed (low pressure) hot water systems. Not compatible with combi boilers or unvented cylinders.

PTFE Tape

A thin, flexible white tape wrapped around threaded pipe and fitting joints before assembly to create a watertight seal. Also known as plumber's tape. Essential for any threaded water connection.

Push-Button Flush

A flush mechanism operated by pressing a button on the top or front of a cistern. Most close-coupled and concealed cisterns now use push-button rather than the older handle mechanism.

Quadrant Shower Enclosure

A shower enclosure with a curved front that fits neatly into a 90-degree corner. The equal-sided design makes efficient use of a corner without taking up much floor space.

Quarter-Turn Tap

A tap that goes from fully closed to fully open with just a 90-degree turn of the handle. Uses ceramic disc technology. Smooth to operate and highly durable.

Rainfall Shower Head

A large, flat showerhead designed to deliver water straight down in a wide, gentle flow. Creates an immersive, drenching effect. Typically ceiling- or arm-mounted. Requires good water pressure and flow rate to perform well.

Rimless Toilet

A toilet pan with no internal rim channel. Water is distributed around the bowl via direct jets, leaving no hidden ledge where bacteria and limescale can accumulate. Widely regarded as more hygienic and easier to clean than rimmed pans.

Riser Rail

A vertical wall-mounted bar that holds a shower handset at an adjustable height. Also called a slide rail or shower bar. Lets different users adjust the shower height without tools.

Roll Top Bath

A freestanding bath with a curved, rolled rim running around the top edge. Traditionally made from cast iron, now also available in acrylic. Typically mounted on decorative claw or ball-and-claw feet.

Safety Glass

Toughened (tempered) or laminated glass used in shower enclosures. If broken, toughened glass shatters into small, blunt-edged pieces rather than large sharp shards. Most shower enclosures carry a safety glass certification.

Sanitaryware

The collective term for the ceramic or vitreous china fixtures in a bathroom: toilet, basin, bidet, and bath. Most sanitaryware is made from vitreous china.

Semi-Pedestal Basin

A basin with a short wall-mounted support that conceals the waste pipe and trap, while leaving the floor visible beneath. A popular compromise between the full pedestal and wall-hung styles.

Semi-Recessed Basin

A basin where roughly half sits on top of a vanity unit and half is recessed into the worktop. Combines the visual appeal of a countertop basin with practical drawer storage below.

Shower Screen

A single glass panel or compact enclosure fitted to the edge of a bath to contain water spray while showering over the bath. A cost-effective alternative to a dedicated shower enclosure.

Shower Tray

The base unit of a shower enclosure that collects water and channels it to the drain. Available in various materials (acrylic, stone resin, ceramic), sizes, and heights including low-profile and level-access options.

Slider Door

A shower door that opens by sliding along a horizontal track. Requires no clearance space in front, making it a practical choice for bathrooms where space is tight.

Slimline Shower Tray

A shallow shower tray designed to sit close to the floor, usually 40mm or less in height. Gives a modern, easy-entry look. Often made from stone resin for added rigidity at low depths.

Soil Pipe

The main drainage pipe that carries toilet waste from the WC pan to the sewer or septic tank. Typically 110mm in diameter. Other waste pipes from basins and showers connect into it.

Stop Valve

A valve in the water supply pipework that can be turned to cut off water flow. Every property has a main stop valve, usually under the kitchen sink. Individual stop valves are also fitted close to each fixture.

Stone Resin

A composite material used for shower trays and basins, made from crushed stone and resin. Heavier and more rigid than acrylic, with a solid, premium feel underfoot. Retains heat and resists flexing.

Tap Hole

A pre-drilled hole in a basin or bath deck for fitting a tap. Basins are available with 0, 1, 2, or 3 holes. The number of holes determines which tap configuration can be used without additional drilling.

Thermostatic Shower

A shower mixer with a thermostatic cartridge that maintains a constant water temperature even if someone uses a tap or flushes a toilet elsewhere in the home. The temperature is set separately from the flow, and most thermostatic valves have a safety stop at 38 degrees.

TMV (Thermostatic Mixing Valve)

A safety valve that blends hot and cold water to a preset safe temperature before it reaches the outlet. Required in care homes and hospitals, and strongly recommended in homes with young children or elderly users.

Towel Radiator

A radiator designed specifically to hang towels, keeping them warm and dry. Contributes to room heating as well. Available as central heating only, electric only, or dual-fuel (both).

Trap

Any curved section of waste pipework beneath a basin, bath, shower, or toilet that holds water to create a seal against drain gases. The most common types are the P-trap and bottle trap.

Undercounter Basin

A basin mounted underneath a solid worktop or countertop with no visible rim above the surface. Creates a seamless, contemporary look. Requires a waterproof worktop material such as stone, solid surface, or treated wood.

Unvented Cylinder

A sealed hot water storage cylinder connected directly to the mains supply, delivering hot water at mains pressure. Common in homes without a combi boiler where high-pressure hot water is desired. Requires annual servicing.

Vanity Unit

A bathroom cabinet that houses a basin on top and provides storage underneath, concealing the pipework. Available as floor-standing or wall-hung. One of the most impactful upgrades for a bathroom renovation.

Vitreous China

The ceramic material used for the majority of toilets, basins, and bidets. Made from clay fired at high temperature with a fused glass-like glaze, making it hard, non-porous, stain-resistant, and easy to clean.

Walk-In Enclosure

An open shower area with no door, accessed through a gap at one end. Water is contained by the angle of the showerhead and a glass screen. Requires a larger floor area than a traditional enclosure but gives a very open, airy feel.

Wall-Hung Basin

A basin fixed directly to a load-bearing wall with no pedestal or furniture beneath. Leaves the floor fully visible, making the room feel larger and cleaning easier. The supply and waste pipes are usually run inside the wall.

Wall-Hung WC

A toilet where the pan is wall-mounted with no floor contact, and the cistern is concealed inside the wall on a carrier frame. Creates a minimal, floating look. Makes floor cleaning easy and allows the pan height to be set to preference during installation.

Waste

The drain fitting at the bottom of a basin, bath, or shower tray that connects to the pipework below. Types include click-clack (push to open/close), slot overflow, slotted, and unslotted wastes depending on the application.

Water Closet (WC)

The formal term for a toilet. Originally referred to a small room containing a toilet. Now used interchangeably with toilet in product descriptions and specifications.

Wet Room

A fully waterproofed bathroom where the shower area is open to the rest of the room with no tray or enclosure. The entire floor is tanked and slopes toward a drain. Gives a seamless, level-access showering experience.

Whirlpool Bath

A bath fitted with water jets around the sides and base that create a massaging, swirling effect. Also called a spa bath. Jets can be water-powered (hydromassage) or air-powered (chromotherapy systems are sometimes included).

WRAS (Water Regulations Advisory Scheme)

UK approval confirming that a plumbing product meets the Water Supply (Water Fittings) Regulations. Products with WRAS approval have been tested to ensure they do not contaminate the water supply. Worth checking for taps, valves, and flexible hoses.