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The Glossary of Terms is here to help you the home improvements enthusiast with an explanation of building terms, and is directly related to the subjects covered in the Projects and Features section of the site. This information is an essential part remodelling, as it is not unusual for the DIY enthusiast to have no knowledge the building trade other than their interest in home improvements

Air brick A brick that allows air to pass through it. These bricks are built into the outer surface of a wall at a low level. The vents allow air to circulate in the area below a timber floor and help prevent the build up of damp moist air that will promote and encourage fungal decay in the timber.
Air dry All building material will have some moisture content [even concrete] Air dry can mean the material is in an equilibrium with the surrounding air that in general has a moisture content [relative humidity] in the range of 40%- 65%
Amperage An unit of electrical current used for measuring its flow to an appliance, providing the necessary wattage.
Aggregate Small particles of sand or stone when mixed with cement make concrete.
Apex The point at which two slopes or angles meet, as with the top of a triangle.  The highest point or peak.
Architrave Decorative timber, fitted around door frame or window, which can be plain or moulded.  Comes in various widths from 43mm and serves two purposes; To cover the gap between the wall and frame/lining, as well as providing a feature, that is aesthetically pleasing.
Angle tie A horizontal timber across a corner of a building tying the wall plates together.
Arris Sharp edge formed by the intersection of two surfaces.
Balanced flue A ducted system in a gas heater.The flue both allows air into the heater and discharges the dangerous burned gas directly out to fresh air. Works in a room sealed gas-burning appliance.
Ballast Naturally occurring sand / gravel mix used in the manufacture of concrete.
Ball valve / Ball cock A valve that allows water to enter a cistern or tank but does not allow the tank / cistern to become so full it overflows. Works on the principal that a spherical ball floats on the water this is attached to a cranked arm, which in turn allows or stops the water flow when the ball rises or falls from a set level.
Baluster / Balustrade Vertical post on a stair, which support the handrail.
Barge board A gable or verge board placed on the inclined end of a roof to cover and protect
Bat A cut piece of brick required to allow odd sized dimensions to be made up
Batt Glass fibre or mineral insulation board.
Borrowed light An internal window in a partition or wall that allows natural light from one room to enter another.
Blistering Seen as raised mounds on a flat felt roof. Indication that the roof is nearing the end of its useful life.
Batten A narrow strip of wood.
Bevel A bevel is when the ninety degree edge is planed to a shallower angle such as eighty degrees, producing a slope.
Built up roofing Felt when laid on a roof in generally three individual layers; hot bonded to the roof deck and the other layers.
Blockboard Sheet material made up of strips of hardwood or softwood, sandwiched between either a hardwood or softwood veneer.  Comes in thicknesses of 25, 18 and 12.5mm
Bradawl A small sharp tipped device (similar to a small screwdriver) for boring small holes into wood, as a start or guide for screws
Cavity The airspace between two leaves of a cavity wall
Cavity bridge When the space between the out and inner leaf of brickwork is bridged, spanning across the cavity airspace. Causes damp patches to occur on inner face of cavity walls. usually caused by old mortar build up on wall ties
Cavity Wall Different to a solid wall, a cavity wall is made up of two walls with a space between the outer and inner wall. The cavity must be a minimum of 50mm, and found in property built after 1932.
Cavity tray A shaped damp proof course at the lintel of a door or window, which allows moisture to escape through weepholes
Chamfer When the corner of the edge of timber is removed at forty five degrees, producing a continues flat surface at that point
Cold Bridges Caused when the cavity of a wall is bridged by a brickwork return or lintel, this can cause the transmission of cold to the inner leaf, causing a cold area where moisture can condense
Coving Cornice material made from plaster or polystyrene
Consumer unit The fuses box in a house, where all the fuses or circuit breakers are positioned.
Coping A decorative stone or concrete cap to a wall. The top part of the wall.
Countersink A type of depression, a tapered hole formed in the material that allows the screw head to lie flush with the surface.
Cylinder Nightlatch A nightlatch that is operated by the rotation of a key in a cylinder
Deadbolt A bolt that is operated in both directions by a key
Deadlock A lock that contains only a deadbolt
Double Glazing Two sheets of glass separated by an air space
Door casing The timber lining of a door opening
Door Furniture Decorative fittings on a door such as handles and plates
DPC Damp Proof Course: A layer of impervious material built into a wall to prevent water from getting into a property. Can be horizontal or vertical. Made from a variety of materials.
Eaves The area on a roof nearest to the bottom of the roof slope and area of hanging tiles
Efflorescence The white powder that can appear on the surface of brickwork and plaster. A residue of alkaline salts drying out of the structure
Escutcheon Decorative plate to cover over a keyhole
Faceplate A not very substantial decorative cover plate usually with a polished finish, designed to cover over a less attractive material such as in the forend of a lock for example.
Fascia The vertical board fixed to the rafter ends or joists, and protrude beyond the wall line. The guttering is usually fixed to them.
Fire Door A solid internal, or external door designed to hold back a fire for a given amount of time.
Flashing Usually made of felt or lead. Waterproofing material fitted against a wall or around a chimney between roof slope.
Forend Part of a lock or latch case from which the bolt, bolts or latch protrude.
Gable end wall The triangular area of wall on the end of the property where there is a double pitched roof.  
Gypsum Gypsum is made from gypsum rock or sand. Its main application is as a building material, mostly for plastering walls and Plasterboard. Other uses including making writing chalk, soil conditioning for agriculture, making moulds for pottery, and as an additive in the manufacture of Ordinary Portland Cement.
Groove A long narrow channel cut in wood, usually in the general direction of the grain.
Handrail A rail at the top of the balustrade  
Hardcore A consolidated bed of hard stone on to which can be constructed a building or structure.
Head When used in relation to framework, the head is the top horizontal member
Head plate The topmost horizontal member in a timber stud partition.
Heave Upward swelling in the ground.
Heel The point at which the intersection of a mitre begins.
Hollow-Core A door that is hollow, not made up with traditional timber members.
Jamb The vertical side member of a door or window frame.  
Joist Timber or metal beams that form a floor or ceiling.
Joist Hanger A steel strap arrangement that a timber joist can be suspended from without compromising its loading.
Keep A component, usually of a rim lock or rim latch, fixed on to the frame to engage a bolt or bolts  
Key A roughened surface formed by sanding with sand papering. The key assists subsequent layers to adhere to the first layer.
Kick Plate A plate fitted to the bottom rail of a door, at the area which will be struck by a shoe.
Laminate Bonding two thin materials together, or cover with thin sheet material.  
Leading Edge The closing edge of a door which meets a doorframe, or casing.
Lever Latch handles Handles designed to be used with a single latch
Lever Lock Handles Handles designed to be used with a Sashlock
Lining A panel of timber or material such as plywood or MDF that makes-up a panel, or covers a wall.  The reveal of a wall opening could be lined where a window is fitted, replacing plaster.
Lintel A horizontal beam over a door or window opening that is carrying the weight of masonry or brickwork. Made of reinforced concrete, steel and originally timber.
Lipping A cover strip, usually to hide a cheaper or combined material, which gives a better finish to an edge.
Lock Block A block of wood that is inserted into 'Hollow Core' doors, providing a solid section of timber for a lock, latch and handles to be fitted to.
Melamine Thin waterproof plastic used to cover an inferior material.  
MDF Medium Density Fiber Board.
Mitre A bisector of any angle.
Mitre Block A device with an angle or angles pre cut, used as a guide to accurately cut predetermined angles, especially useful when cutting the same angle many times.
Muntin A vertical member with grooved edges used in the manufacture of panelled doors. A muntin would be added between two horizontal rails, dividing a single panel area into two.
Mortice latch A latch for fixing in a mortice cut into the closing edge of a door or window
Mortice Lock A lock for fixing in a mortice cut into the closing edge of a door
Mortice A rectangular recess cut into timber to receive a matching tongue or tenon.
Mullion The vertical division in a window frame
Nogging Short horizontal timber fixed between two studs  
Packing Square pieces of either plywood or hardboard of varying thicknesses. They are used to make-up the gap between a casing (or frame) and the wall that you are fixing to.  
Pad A square piece of softwood timber that a bricklayer inserts 'dry' into the brickwork joints. The grain of the timber runs the width of the brickwork and is used for fixing casings and frames to masonry.
PAR Planed All Round. The timber has been planed face, back and both edges.
Parting Bead A parting bead as used in the manufacture of sliding sash windows. Fits into a groove in the pulley stile to form two channels for the sash to run.
Partition Internal dividing wall
Plumb When the vertical member is plumb
Pilot Hole Screws produce outward pressure when driven into wood, which can cause it to split or the screw to snap. By first drilling a smaller diameter hole (pilot hole) into the material reduced this outward pressure.
Profile The outline shape when viewed from the side (end view)
Reveal The vertical sides of an opening in a wall at a door or window  
Rebate A stepped recess along the edge of a workpiece.  A piece of glass or a door would fit into it
RSJ Rolled steel joist. A steel beam, the cross section forms the letter I
Sash The opening part of a window.  
Sashlock A lock that also operates a latch action with lever lock handles
Scant Cheaper 'planed all round' (PAR) white wood, mass produced for general carpentry work, such as partitioning or sub framework.
Scribe To copy closely the profile of a surface onto an adjacent material, then cut and fit the material to fit this profile
Shank The stem of the bit, or screw.
Sill The lowest horizontal member of a window, or door frame. The projection acts to divert water away from the building.
Soffit The underside of any building feature that can be seen.  For example, where the roof overhangs an external wall, plywood is usually fitted horizontally between the back of fascia board and the face of the brickwork, covering the underside of the roof members. This would be a soffit.
Skirting Board Decorative molded timber boards that hide the joint between the walls and floors, that also protect the walls against low level damage.
Sliding Sash The opening part of a window that moves vertically up or down. Used in the Sliding Sash Window which has weights and cords to make the operation easier.
Sole Plate The timber member that is to the base of a timber stud partition, which is fixed to the existing floor
Spindle Square steel bar used in conjunction with lever lock, and lever latch handles. Fits into both handles, and inserted through the lock or latch, revolves when the handles are pushed down, and pulls back the latch.
Staff Bead A return bead with a quirk at each side. Refers also to the beaded strip which holds a sash window in place.
Straight-Edge A length of timber (75mm x 18mm) to a required length, with straight parallel edges.  Could be used for checking jambs for being straight, or as an extension to the spirit level.
Stile Vertical side member.
Stud A vertical member of a timber partition.
Stud Partition An interior timber framed wall (Studding)
Striking Plate The metal plate of a mortice lock or latch, which is fixed into the frame to engage the bolt.
Tanking A waterproofing layer, generally asphalt, but can be other specialist materials.  
T&G Tongue and Groove. A jointing method used for boarding such as floor boards and wall panelling boards.
Tee hinge A long strap like hinge in the general shape of a T.
Template A pattern cut to the shape of anything to allow a good close fit of the final product.
Tenon A projecting tongue at the end of a length of timber which fits into matching mortice.
Thermostatic valve An automatic valve fitted to a radiator that reduces the flow of hot water through the radiator when air temperature in the room reaches a pre-set level.
Thinners A solvent used to dilute paint and varnish.
Tie bar A rod and plate washer system used to prevent further movement within a structure. Tie rod is positioned through a structure, with plates placed against the outside walls in an attempt to stop any further outward movement of the wall, or walls.
Timber framed construction A house constructed from an internal timber frame with an outer skin of brick or blockwork. Timber stud /timber partition. A partition that has as its Loadbearing core timber studs
Timber Plug A Length of softwood timber, specially shaped by axe, which is driven into raked out mortar joints.  It provides a secure fixing point when fixing window and door frames to masonry.
Toe The furthermost point of the mitre cut, opposite to the 'Heel'
Toughened glass Glass made with the outer surfaces heat-treated to enhance its strength.
Transom A horizontal dividing member of a window or door frame. In a door the horizontal division between door and glazed area above the door
Throat A drip inducing recess or rebate in a timber sill or similar. Any groove in timber on the underside of a sill will induce water to drip from this point.
Trickle vent In a window the thin controllable hit and miss ventilator that allows a small quantity of air to circulate into the room.
Trimmer Joist or that are set at right angle to floor or ceiling joists to form an opening.
Tuck In a felt or lead flashing the tuck refers to the place where the lead / felt actually turns into the wall. This area is then mortared up to enhance its ability to withstand water penetration.
Two gang switch An electrical switch or outlet with two individual switches contained within the one unit.
Valley gutter A gutter between the intersection of two sloping pitched roof surfaces  
Vapour barrier A water impervious sheeting layer
Ventilation pipe A drainage pipe that passes through a structure to terminate at high level in the open air. A pipe that allows sewer smell and sewer gas to vent to atmosphere outside a property
Veneer A thin layer of fine wood, to cover a cheaper type, giving the appearance of a solid piece
Verge The edge of a pitched roof at the gable
Verge board A timber board that covers the roof edge at the gable
Wall tie A specially shaped strip of metal or wire built into the mortar beds of a cavity wall, the wall tie then spans the cavity thus adding strength to the wall. Wall ties are generally spaced every 450 mm.  
Wall plate A horizontally positioned timber laid along the top of a wall to distribute evenly the load from the rafters that are fixed to it
Wagtail A suspended timber strip that creates a division between the weights of a sliding sash window
Warp To bend or twist.Timber exposed to moisture or heat can warp, twist, and deform.
Water Vapour Water vapour is water in its gaseous state-instead of liquid or solid.
Water hammer Vibration in a plumbing system. The noise from the pipework cause varies, caused by variations in temperature within the pipes, and design of the system
Waste pipe A pipe, which carries wastewater from a wash hand basin, bath, or sink to a drain.
Weatherboarding Horizontal interlocking or horizontal lapped timber or plastic boards fixed to the external surface of a property.
Weep hole Small outlet hole built into the brickwork outer leaf to allow water to escape from a damp proof course above a door or window
Wet rot One of the two most common wood destroying fungus
Window board Horizontal board fixed internally at sill level.
Window head The internal board at the Soffit of a window opening
Wood Bit A bit designed specifically for boring holes into wood, different to steel drilling bits.