Acrylic Cast - Acrylic sheet is durable and long lasting glossy thermoplastic material which can be vacuum formed into products such as baths and shower trays. It sometimes has the trade name of 'Lucite' or 'Perspex'.

Acrylic Bath - Acrylic Sheet which has been vacuum formed into a tub shape then sprayed with Glass Reinforced Polyester (GRP) to give the bath extra strength and rigidity.

Adjustable feet - For all types of bath, adjustable feet are essential to allow the installer to ensure the bath is perfectly level during installation. 

Airlock - Section of plumbing pipework which, due to its layout, traps a pocket of air resulting in little or no water through it. 


Backflow - Flow through a pipe in a direction contrary to the intended direction.

Back Syphonage - Back flow created by the syphonage of liquid from the cistern or appliance into the pipe feeding it, possibly causing contamination of the liquid. 

Bar - The unit of measurement of water pressure. 1 Bar pressure is equal to the pressure exerted by a column of water 10 metres high. So a 1 metre column of water exerts a pressure of 0.1 bar. 

Baseboard - A shaped plywood or chipboard plank bonded to the underside of an acrylic bath to strengthen it. May be ledt exposed or 'encapsulated' within the GRP layer for increased water resistance. 

Basin Mixer - For use with either a one taphole washbasin or a three taphole washbasin. Supplied with hot and cold water through two separate half inch inlets. May be single or dual flow.

Bath Feet - Some stand-alone acrylic or cast iron baths have separate decorative support feet. These are manufactured from cast iron or brass. 

Bath filler or mixer - A mixer tap, bigger than a basin mixer, which is usually mounted directly onto the bath. Sometimes available as a wall mounted version. 

Bath/Shower mixer - Mixer taps which are similar to the bath filler but with the addition of a shower hose and sprayhead. Designed for mounting directly onto a bath and having separate hot and cold water inlets, but with a lever operated diverter mechanism which directs water from the usual filler spout to a hose and sprayhead. The sprayhead (or shower head) can be fixed to the wall in an adjustable bracket or it can be hand held. Sometimes available in thermostatic versions. 

Bidet - A 'sit on washbasin'. Provides a simple means of ensuring personal cleansing. May be floor standing, wall hung or back-to-wall in similar style to the WC.

Boiler - A device for generating hot water for central heating or domestic hot water. Heat from the external source is transmitted to water contained within the tubes in the boiler shell. This water is delivered to the radiators or taps at the desired pressure, temperature and quality. 

Booster Pump - See shower pump

Bottle Trap - Small Plastic or metal unit connected to the outlet and forming a water seal on the underside of a washbasin to prevent foul air passing into the bathroom for the drains.

Brassware - The generic name for all types of taps and mixers. 


Cast Iron Bath - Formed by pouring molten iron into a mold. The bath is covered in porcelain enamel to give a long lasting and attractive surface. 

Ceramic Disc Technology - (Ceramic Cartridge). Small, perforated, ceramic discs (rather than traditional rubber washer valves) within the body of a tap which regulate the water flow of water when the tap head is turned. Usually the tap is turned fully off to fully on by rotating the handle through to just 90 degrees. 

Check Valve - A plumbing fitting designed to allow water to flow in one direction only. 

Cistern - The ceramic, stainless steel or plastic tank containing water used for flushing the WC.

Cistern displacement device 

The may be bags, bottles or even house bricks placed inside the cistern tank to restrict the amount of water used at each flush. Some of these devices can seriously impair the flushing action of the WC and may result in the consumer having to flush the WC several times to clear its contents. This results in more water being actually consumed than necessary. 

Cradle - The support system for a cast iron or enameled steel bath. A cast iron bath usually has four cast iron or brass feet bolted into position on the underside of the bath. For steel it is usually a steel or plastic support cradle with adjustable feet, fixed at each end of the bath. 

Cross Flow - Water flowing from one side of a mixing valve to the other, possibly causing contamination of the supply. 

Cold water cistern - the large tank, in your loft, which feeds your cold taps and the hot water cylinder. Most common in older properties. 

Combination Boiler (Combi) - Gas fired jets heat water as it is required for either domestic hot water (for the use of the shower, bath and washing) or for the central heating. The boiler starts immediately when the tap or shower is turned on or hen the heating thermostat activates. A higher rated boiler will give greater water flow. Does not require a cold water cistern. 

Concentric Control - On a shower control, an outer knob is turned to adjust water flow. An inner knob adjusts the temperature. 

Concealed cistern - The cistern is hidden from view either behind the wall or inside bathroom furniture. Has the same function as a more usual exposed cistern.

Corner Bath - A special shape of bath with two sides of identical length and with a bowed front which allows it to be fitted into the corner of the bathroom. Available in a number of sizes to suit the space available.