Plumbers Glossary

A

Airlock – A blockage in a pipe caused by a trapped air bubble.

Appliance – Any machine or device that is powered by electricity.

B

Back-siphoning – Siphoning of part of a plumbing system due to the mains water pressure failing.

Banjo unit – A combined waste and overflow unit.

Base coat – A flat coat of paint over which a layer of glaze is applied.

Batten – A narrow strip of wood, usually fixed to a wall to act as a support for a unit or shelving.

Bevel – Any angle at which two pieces of wood meet, other than a right angle.

Bore – The hollow part of a pipe.

Butt joint – A simple joint where two pieces of wood are fixed together with no interlocking parts cut in them.

C

Cam and stud fixing – A simple fixing used in flat-pack construction.

Cap-nut – A nut used to tighten a fitting onto pipework.

Cavity wall – A wall made of two separate, parallel masonry skins with an air space between.

Chamfer – A flat, narrow surface along the edge of a workpiece, usually at a 450 angle to any adjacent surfaces.

Chase – A groove cut in masonry or plaster for electrical cabling or pipework.

Circuit – A complete path through which an electric current flows.

Conductor – A component, usually a length of wire, along which an electric current will pass.

Consumer unit – The box containing all the fuse ways that protect the individual circuits in the house. The main on-off switch is located here, enabling you to isolate the power supply to the whole house.

Counterbore – A tapered recess that allows the head of a screw or bolt to lie below a surface; also to cut such a recess.

Countersink – To cut a tapered recess that allows the head of a screw or bolt to lie flush with a surface.

Cup – To bend as a result of shrinkage; usually referred to as across the length of a piece of wood.

D

Damp-proof course (DPC) – A layer of impervious material that prevents moisture rising through a floor or in a wall.

E

Earth – A connection between the earth or ground and an electrical circuit; also a terminal to which this connection is made.

Extension lead – A length of electrical flex for the temporary connection of an appliance to a wail socket.

F

Face edge – A woodworking term for a surface that is planed square to the face side (see below).

Face side – A woodworking term for a flat, planed surface from which other angles and dimensions are measured and worked.

Fence – An adjustable guide to keep the cutting edge of a tool a set distance from the edge of a workpiece.

Flat-pack – Furniture or units supplied in pieces and assembled by the purchaser, using knock-down fittings.

Four-way – A block of four electrical sockets connected to a wall socket by an extension lead.

Free-standing – Furniture or units that are not built-in or fixed to a wall or floor.

Fuse board – A unit where a main electrical service cable is connected to the circuits in a house; also a term covering a meter, consumer unit, etc.

G

Galvanized – Covered with a protective coating of zinc.

Grain – The direction of wood fibres in a particular workpiece; also a pattern on the surface of timber made by cutting through the fibres.

Groove – A long, narrow channel cut in plaster or wood; in the latter, this follows the direction of the grain.

Grounds – Strips of wood fixed to a wall to provide nail- fixing points for skirting boards, etc.

H

Housing – A long, narrow channel cut across the general direction of wood grain to form part of a joint.

I

Insulation – Material used to reduce the transmission of heat or sound; also a non-conductive material around electrical wires or connections to prevent the passage of electricity.

Isolating valve – A valve used to shut off water from a particular room or appliance, so as not to have to turn off the entire water system.

J

Joist – A horizontal wooden or metal beam (such as a RSJ) used to support a structure such as a floor, ceiling or wall.

K

Key – To roughen a surface to provide a better grip when it is being glued; also the surface so roughened.

Knock-down (KD) – Another name for flat-pack furniture or units.

Knock-down (KD) fittings – Fittings and fixings supplied with flat-pack furniture or units by the manufacturers, typically including screws, bolts and cam and stud fixings.

Knotting – Sealer, made from shellac, that prevents wood resin bleeding through a surface finish.

Knurled – On a knob or handle, a series of fine grooves impressed into an edge or surface to improve the grip when turned or handled.

L

Laminate – Two or more sheets of material bonded together; or the top waterproof sheet of the bonded sheets used as a work surface; also to fix such sheets together.

Lintel – A horizontal beam used to support the wall over a door or window opening.

Lipping – A decorative strip applied to the side edges of laminated boards.

M

MDF – Medium-density fibreboard, a man-made sheet material that can be worked like wood and is used as a substitute for it.

Mitre – A joint between two pieces of wood formed by cutting 450 bevels at the end of each piece; also to cut such a joint.

N

Noggin – Horizontal reinforcing timber fixed between the vertical studs in a stud partition wall.

P

Pilot hole – A small-diameter hole drilled to act as a guide for a screw thread.

Primer – A coat of paint applied to wood or metal to seal it and act as a first coat.

Profile – The outline or contour of an object.

PTFE – tape Tape made from polytetrafluorethylene, used to seal threaded plumbing fittings.

R

RCD – Residual circuit device, a device that monitors the flow of electrical current through the live and neutral wires of a circuit.

Rebate – A stepped rectangular recess along the edge of a workpiece, usually forming part of a joint; also to cut such a recess.

Reveal – The vertical side of an opening.

Rising main – A pipe that supplies water under mains pressure, usually to a roof storage tank.

S

Score – To scratch a line with a pointed tool.

Scribe – To copy the profile of a surface on the edge of sheet material to be butted against it; also to mark a line with a pointed tool.

Sheathing – An outer layer of insulation on an electrical cable or flex.

Short circuit – Accidental re-routing of electricity to earth, which increases the flow of current and consequently blows a fuse.

Silicone mastic – A non-setting compound used to seal joints.

Spur – Branch cable that extends an existing electrical circuit.

Stud partition – A timber frame interior dividing wall.

T

Template – A cut-out pattern, made from paper, wopd, metal etc, used to help shape a workpiece accurately.

Terminal – A connection to which bared ends of electrical cable or flex are attached.

Trap – A bent section of pipe (below a bath, sink, etc) containing standing water to prevent the passage of gases.

U

U-bend – A waste pipe, or part of one, shaped like a U, used as part of a trap.

Undercoat – A layer or layers of paint used to cover primer and build up a protective layer before a top coat is applied.