GLOSSARY OF TERMS. Feel free to use our helpful list of key terms used within the industry we operate.
Airbrick – A perforated brick built into a wall for the purpose of providing air for ventilation purposes. Used, for instance, to ventilate the underside of a wooden floor or a roof space.
Architrave – A moulding around a doorway or window opening. It usually covers the joints between the frame and the wall finish, thus hiding any shrinkage gaps that may occur.
Asbestos Cement – Material used in the past for insulation. Can sometimes be a health hazard – specialist advice should be sought if asbestos (especially blue asbestos) is found.
Asphalt – Cement mixed with 15% asbestos fibre as reinforcement.
Back Boiler – A boiler fitted at the back of the hearth of an open fire or behind a gas fire to provide hot water and/ or central heating
Back Land – Site with no road frontage surrounded by other development or land in other ownership.
Balanced Flue – Common metal device, normally serving gas appliances, that allows air to be drawn into the appliance whilst also allowing fumes to escape
Ballast – Sand and gravel mixture used fore making concrete etc.
Baluster – A post or vertical pillar supporting a hand rail or parapet rail.
Barge Board – Timber, sometimes decorative, placed at the verge of a roof.
Balustrade – A collective name for a row of balusters or other infilling below a hand rail on a stair or parapet.
Bark Borer – Woodworm found only in dark and sapwood, generally harmless.
Batten – A strip of timber, as used for the fixing of slates and tiles to the roof.
Bay Window – A window formed in a projection of a wall beyond its general line.
Bearer – A horizontal timber used to spread loads, for example across ceiling or floors.
Beetle Infestation – Larvae of various species of beetle (wood boring insects e.g. woodworm) can tunnel into timber causing damage. Specialist treatment is normally required. Can also affect furniture.
Benching – Shaped concrete slope beside drainage channel within an inspection chamber. Also known as “haunching”
Binder – A timber beam such as that used horizontally across ceiling joists to reduce the span of a ceiling.
Birdsmouth – Triangular cut out of roof strut to tightly wedge purlin.
Bessemer – Beam, usually timber, over staircase head.
Bitumen – Black, sticky substance, similar to asphalt. Used in sealants, mineral felts and damp-proof courses.
Bituminous Felt – Sheeting based on asbestos, firbreglass or other fibres impregnated with bitumen, used in various forms for covering flat roofs or for damp proof courses.
Blackash Mortar – Industrial ash used instead of sand with cement and lime.
Blockwork – Masonry of precast concrete blocks.
Blown – Defective render of plaster lifting from base, hollow and loose.
Bond – The regular arrangements of bricks or stones in a wall so that the units may be joined together. The principal types of “bond” used in domestic construction being English, Flemish, header, stretcher, diagonal or garden wall bond.
Borrowed Light – Window in internal wall between rooms, often over door.
Breather Membrane – Timber frame construction wall membrane allows moisture to escape.
Breeze Block – Originally made from clinker cinders or ”breeze” the term now commonly, but incorrectly, used to refer to various types of concrete and cement building blocks.
Bressumer – A long heavy lintel, usually timber, supporting brickwork or masonry, often over a shop window.
Building Regulations – National regulations specifying minimum standards of construction for new buildings, extensions and alterations enforced by local authority.
Building Survey – Formerly structural survey.
Built-up Roofing – Two or more layers of bituminous felt laid in bitumen, used on flat roofs. Normally has a life expectancy of approximately 15 years.
Calcium Silicate Bricks – Subject to thermal expansion and contraction resulting in cracking
Calorifer – Heating coil of pipework within copper hot water cylinders.
Capillary Action – Upward movement of moisture in walls and floors.
Carbonation – A natural process affecting the outer layer of concrete. Metal reinforcement within that layer is liable to early corrosion, with consequent fracturing of the concrete in some cases.
Casement Window – A window composed of hinged, pivoted or fixed sashes.
Cast-in-situ – Concrete or other material cast on site within timber or other framework.
Caulking – Sealing to edges around baths and showers.
Cavity Tray – A damp proof course across a cavity wall, sloping downwards form the inner skin to outer skin to prevent dampness crossing the cavity above door and window openings.
Cavity Wall – Traditional modern method of building external walls of houses and buildings, comprising two leaves of brick or block work usually separated by a gap (cavity) of approximately 50mm.
Cavity Wall Insulation – Filling of wall cavities by one of various form a of insulation material:
Beads: Polystyrene beads pumped into the cavities. Will easily fall out if the wall is broken open for any reason.
Foam: Urea Formaldehyde foam, mixed on site and then pumped into cavity where it sets. Can lead to problems of dampness and makes the replacement of wall ties more difficult.
Fibreglass: Inert mineral fibre pumped into the cavity.
Cavity Wall Tie – A twisted piece of metal or similar material bedded into the inner and outer leaves of cavity walls intended to strengthen the wall. Failure by corrosion can result in the wall becoming unstable, specialist replacement ties are then required.
Cesspool – A simple method of drain comprising of a holding tank that need frequent emptying. Not to be confused with a septic tank.
Cheek – The side of a dormer
Chimney Pot – A short, usually earthenware pipe placed on the top of a chimney to improve the draft (see flue)
Chipboard – Sometimes referred to as “particle board”. Chips of wood compressed and glued into sheet form. Cheap method of decking to flat roofs, floors and furniture, especially kitchen units (with Formica or melamine surface).
Cistern – A water storage tank such as that installed in the roof of a house or the tank containing the water to flush a WC.
Cladding – On-load bearing covering to the walls or roof of a building, often of slate, tiling or timber.
Cleaning Eye – Sometimes known as an “access eye” or rodding eye”. An opening in a drain or ventilation pipe, covered by a plate, the removal of which allows the drain to be rodded to clear blockages.
Cob – Walling of damp earth, sometimes mixed with cement, rammed without reinforcement into a formwork. This cheap method of walling has in the past been practiced mainly in East Anglia and the west of England.
Code of Measuring Practice and Code of Practice
Non statutory recommendations for the use of building materials and techniques.
Collar – Horizontal timber member designed to restrain opposing roof slopes. Absence, removal or weakening can lead to roof spread.
Collar Beam – A horizontal tie beam of a roof that is joined to opposing rafters at a level above that of the wall plates.
Column – An upright post, generally of concrete, stone, brick, steel or timber supporting load from above.
Combination Boiler – Modern form of gas boiler that activates on demand, usually within a pressurised system. With this form of boiler there is no need for water storage tanks, hot water cylinders, etc.
Comparables – Other properties sold or values to which reference is made when valuations are prepared.
Concrete – A hard, stone like mass consisting of a mixture of sand and stone by cement.
Condensation – Water condeses on surface when it is colder than the dew point of the surrounding air.
Coniophora Puteana – A common form of wet rot fungus.
Consumer unit – Fuse or circuit breaker box controlling electricity supply.
Continuity of Cover – Insurance cover against subsidence or other risks carried on from one property owner to the next.
Conversion – Property now used differently, e.g. flat within former house.
Coping Stone – Usually stone or concrete, laid on top of a wall as a decorative finish and designed to stop rainwater soaking into the wall
Corbel – Projection of stone, brick, timber or metal jutting out from a wall to support weight above it.
Core Sample – Drilled out section of concrete or other material taken for analysis.
Cornice – A moulding at the top of an outside wall or where an inside wall abuts the ceiling.
Coving – Curved junction between wall and ceiling
Cowl – A tile or metal cover, often fixed over a chimney
Creasing Tile – One or two courses of plain tiles laid under bricks copings, projecting slightly from the face or the wall to prevent moisture running down.
Creep – Spreading and folding of lead or asphalt on roofs and steps especially due to heat from sun.
Cross Wall – Wall running from side to side.
Cruck – Irregular sections of tree trunk used for rafters and other rough carpentry.
Curtain Wall – Lightweight thin outer panel Wall
Curtilage – Enclosed garden area belonging to dwelling
Damp Proof Course – Also known as DPC. A layer of impervious material (mineral felt, pvc, etc) incorporated into a wall and designed to prevent dampness rising up the wall, or lateral dampness around doors, windows, etc. Various proprietary methods are available for damp proofing existing walls, including “electro-osmosis” and chemical injection.
Damp Proof Membrane – Also known as DPM. A layer of impervious material, often polythene, fixed to or under the subfloor to prevent moisture affecting the floor. DPMs can also come in liquid format and are usually used when the existing moisture content of the screed is too high to fit a timber floor.
Deathwatch Beetle – (Xestobium Rufovillosum) Extremely serious insect pest that attacks structural timbers. Usually affects old hardwoods with fungal decay already present.
Dentil – Tile fillet to seal joint at base of sack or parapet.
Desiccation – Shrinkage of subsoil, usually clay, associated with moisture extraction from trees, often leading to subsidence.
Detailing – Flashings, upstands, soakers and other roof joint weather sealing.
Dishing – Sagging to centre of floor or roof slope.
Dormer (Window) – A vertical window through a pitched roof, usually provided with its own flat or pitched roof.
Double Glazing – A method of thermal insulation, usually either:
Sealed Unit: Two panes of glass fixed and hermetically sealed together;
Secondary: In effect a second “window” positioned inside the original window.
Downpipe – A downpipe (or downspout) is a vertical pipe for carrying rainwater from a rain gutter to ground level. There the water is directed to a sewer, rainwater harvesting, or let into the ground through seepage
Dry Lining – A lining to the inside of a wall, usually plaster board fixed to battens or timber dabs.
Dry Rot – A very serious form of fungus that attacks structural and joinery timbers, often with devastating results. Can flourish in moist unventilated areas.
Efflorescence – Powdery white salts crystallized on the surface of a wall as a result of moisture evaporation.
Electro-osmosis – Propriety system for preventing rising damp by electrically earthing wall.
Endoscope – Borescope for inspecting inside wall cavities etc.
Engineering Brick – Particularly strong and dense type of brick, often used as a damp proof course in older buildings.
Eyebrow Window – Set into roof slope under curving rows of tiles.
Fascia – A flat band or surface, a part of an architrave or cornice.
Fibreboard – Cheap, lightweight board material of little strength, used in ceilings or as insulation to attics.
Fillet – A narrow strip fixed at the angle between two surfaces, e.g. cement fillet where a chimney stack abuts roof tiling.
Finlock Gutters – Proprietary name for interlocking concrete gutter system.
Firring – A timber strip laid along joist to provide a gradual slope to a flat roof.
First Fixing – Installation of services and fittings prior plastering.
Flank Wall – The wall at the side of a building.
Flashing – Building technique designed to prevent leakage at a roof joint. Normally metal (lead, zinc, copper) but can be cement, felt or proprietary material.
Flat Roof – A roof nearly horizontal, constructed of such material as allows the water to run off freely from a very slight inclination.
Flaunching – A cement mortar weathering on the top of a chimney stack surrounding the base of the chimney pots to throw off the rain and thus prevent it from saturating the stack.
Flue – A smoke duct in a chimney, or a proprietary pipe serving a heat producing appliance such a central heating boiler.
Flue Lining – Metal (usually stainless steel) tube within a flue – essential for high output gas appliances such as boilers. May also be manufactured from clay and built into the flue. Other proprietary flue liners are also available.
Flight – Straight run of staircase.
Flush Door – A smooth faced door, normally of plywood or hardboard with either a hollow or solid core.
Flying Freehold – In England and Wales the ownership of airspace over another freehold.
Flying Shore – Temporary support support in gap between buildings, generally during redevelopment.
Foul Drain – A drainpipe that carries off wastes from a plumbing fixtures.
Foundation – Normally concrete, laid underground as a structural base to a wall; in older buildings these may be brick or stone.
Frog – An indention, usually V shaped, in the bedding face of the brick to reduce its weight. “Frog down” or “Frog up” are the generally accepted ways of describing how the bricks are laid.
Gallopers – Temporary timber struts under converging chimney brickwork in roof space.
Galvanic Corrosion – Number of sockets or switches.
Gang – Prefabricated roof timbers fixed with metal plates.
Gang Nail Trusses – Rusting of galvanised steel in presence of lead and copper.
Going – Staircase distance between risers.
Gravity Circulation – Wide bore heating circulation without pump
Ground Heave – Swelling of clay sub-soil due to the presence of moisture: can cause an upward movement of foundations in extreme cases.
GRP – Glass fibre reinforced plastic.
Grout – Filling of joints in paving and tiling.
Gully – An opening into which rain and waste water are collected before entering the drain.
Gusset – Web stiffener to structural member, i.e. roof rafter.
Gutter – A channel along the eaves of a roof or the edge of a path for the removal of rainwater.
Gypsum – Modern plaster material used in plasterboard and for plaster skin.
Haunching – Shaped concrete slope beside drainage channel within an inspection chamber (also known as “benching”). Also a term used to describe the support to a drain underground.
Header – Brick laid with end showing.
Heave – Lifting of foundations due to clay swell or other expansion of support below.
Herringbone Strutting – Timbers laid in X-pattern between joists.
Hip – The external junction between two intersecting roof slopes.
Hip Hook – Metal bracket holding bottom hip tile in place.
Hip Roof – (Or hipped roof) A four-sided roof having sloping ends and sides.
Hip Tile – A saddle shaped or angular tile fitting over the intersection of those roof tiles which meet the hip.
Hoggin – Hardcore.
Honeycomb Wall – Bricks laid with gaps to allow ventilation.
Hopper Head – An enlarged top to a vertical pipe into which rainwater or waste water discharges.
Hot Water Cylinder – A cylinder for the storage of hot water, often fitted with a electric immersion heater.
In Situ – “In position” – applied to work done in the position where it is finally required, eg concrete may be precast in sections which are later taken to the position where it is required or it may be cast “in situ”.
Inspection Chamber – Commonly called the “man hole”: access point to a drain comprising a chamber (of brick, concrete or plastic) with the drainage channel as its base and a removable cover at ground level.
Interceptor – A trap fitted between a house drain and a main sewer to separate in the air in each.
Invert – Bottom of manhole or drain. Invert level is distance below ground.
Jamb – Vertical side face of a doorway or window.
Joist – A timber or steel beam directly supporting a floor and sometimes alternatively or additionally supporting a ceiling. Steel beams are usually referred to as RSJs (rolled steel joists).
Joist Hanger – A steel shoe which supports the end of a joist.
Lath and Plaster – Thin timber strips with wet plaster coatings.
Lath – Thin strip of wood used in the fixing of roof tiles or slates, or as backing to plaster.
Lintel – A horizontal beam over a door or window opening usually carrying the load of the wall above. Often lintels can be partially or completely hidden from view.
Longhorn Beetle – (Hylotrupe Bajulus). A serious insect pest mainly confined to the extreme south-east of England, can totally destroy the structural strength of wood.
LPG – Liquid Petroleum Gas or Propane. Available to serve gas appliances without mains gas. Requires a storage tank.
Mastic – Any permanently plastic and sticky waterproof material used for sealing exterior joints in buildings.
Microbore Heating – Narrow flexible pipework.
Mineral felt – Flat roof covering, usually bitumen based.
Mono Pitch Roof – Has only one slope from high wall to low wall.
Mortar – Mixture of sand, cement, water and sometimes lime used to join stones or bricks.
Mortar snots – Mortar splashes over brick faces.
Mullion – Vertical bar dividing individual lights in a window.
Oversite – Rough concrete below timber ground floors.
Pantiles – Undulating shaped interlocking tiles.
Parapet – Low wall along the edge of a roof, balcony etc.
Parapet Gutter – A timber gutter of rectangular cross-section usually provided with a flexible metal or other impervious lining. Used behind a parapet or sometimes a valley.
Parging – Cement lining around the inside of a chimney flue.
Parquet – Tongue and grooved, secret nailed, hardwood flooring.
Partition – A non-load bearing wall between rooms.
Party Wall – On boundary between properties in separate ownership.
Pier – A vertical column of brickwork or other material, used to strengthen the wall or to support a weight.
Piles – Concrete columns driven or cast in subsoil as foundations.
PIR Sensor – Passive InfraRed Sensor – A Pyro Electric InfraRed Sensor is an electronic device which measures InfraRed (light radiating from objects in its field of view).
Plasterboard – Stiff “sandwich” of plaster between coarse paper. Now in widespread use for ceilings and walls.
Plate – Horizontal timber on wall to spread load of joist and rafter ends.
Plinth – Widening at base of wall, typically cement rendered.
Plumb – Vertical. Hence plumb line to test for verticality.
Pointing – Outer edge of mortar joint between bricks, stones etc.
Ponding – Water lying on flat roofs.
Powder Post Beetle – (Bostrychide or Lucitdae family of beetles). A relatively uncommon pest which can, if untreated, causes widespread damage to structural timbers.
Purlin – Horizontal beam in the roof upon which rafters rest.
Random Bubble – Basic early method of stone wall construction with no attempt at bonding or coursing.
Rendering – Vertical covering of a wall either plaster (internally) or cement (externally), sometimes with pebbledash, stucco or Tyrolean textured finish.
Retaining Wall – Holds back land behind and may thus support structures behind also.
Reveals – The side faces of a window or door opening.
Ridge – The highest part or apex of a roof, usually horizontal.
Ridge Tile – A specially shaped tile for covering and making weather tight the ridge of the roof. These tiles may have a rounded or angular cross-section.
Riser – The vertical part of a step or stair.
Rising Damp – Moisture soaking up a wall from below ground, by capillary action which can cause rot in timbers, plaster decay, decoration failure etc.
Roof Spread – Outward bowing of a wall caused by the thrust of a badly restrained roof framework (see “collar”).
Roughcast – Unevenly finished external render.
RSJ – Frequently used abbreviation for a rolled steel joist.
Sash Window – A window in which the opening lights slide vertically within a cased frame, counter balanced by weights supported on sash cords, which pass over pulleys in the frame.
Screed – Final, smooth finish of a solid floor; usually cement, concrete or asphalt.
Scrim – Hessian type material used t seal joints in platerwork.
Septic Tank – Drain installation whereby sewage decomposes through the action of bacteria, which can be slowed down or stopped altogether by the use of chemicals such as bleach, biological washing powders etc.
Sets – Small stones used for paving.
Settlement – All properties settle to some extent, and this can show as cracking and/or distortion in walls. Very often minor settlement is not of great significance to the building as a whole.
Sewer – A large, underground pipe or drain used for conveying waste water and sewage. The Local Authority is usually responsible for the sewers, which collect the effluent from various drains, the drains being the responsibility of the land owners.
Shakes -Vertical crack due to part of wall moving down.
Shear -Breaking away of surface to plasterwork of other finish.
Shelling -Small rectangular slabs of wood used on roofs instead of tiles, slates etc.
Shingles -Small rectangular slabs of wood used on roofs instead of tiles, slates etc.
Shiplap – Overlapping boarding as cladding to external face of wall.
Sleeper Wall – A low brick wall supporting the floor joists of a suspended timber ground floor.
Sleugh – Land drain with pipes butted together.
Snagging – Minor building works to be finished off after practical completion.
Soakaway -A pit, filed with broken stones etc below ground to take drainage from rainwater pipes or land drains and allow it to disperse.
Soaker -Piece of flexible metal fitted to interlock with slates or tiles and make a watertight joint between a wall and a roof or at a hip or valley. Stepped flashings are used over the soakers at a joint against a wall.
Soffit -The underside of an arch, beam, staircase, eaves or other feature of a building.
Soil-and-vent Pipe -A vertical pipe conveys sewage to the drains. Its upper end is usually vented above the eaves.
Soldier Arch – Bricks laid on end as lintel to opening.
Solid Fuel – Heating fuel, normally wood, coat or one of a variety of proprietary fuels.
Spalling – Space above and to the sides of an arch; also the space below a staircase.
Spandrel -Cement render finished with small white stones.
Spindles -Vertical uprights to balustrades and staircase handrails.
Spine Wall – Internal wall running front to back.
Stitch Bonding – Repair to brickwork, cutting in new bricks.
Stopcock – A valve on a gas or water supply pipe which is used to cut off the supply.
Stretcher – Brick laid sideways.
String – Sloping board at either side of the treads on a staircase, supporting the treads and risers.
Strutting – Angles timbers supporting purlins and rafters.
Stucco – Smooth cement rendering as external finish.
Stud Partition – Lightweight, sometimes non-load bearing wall construction comprising a framework of timber faced with plaster, plasterboard or other finish.
Subsidence – Ground movement, leading to downward displacement of foundations. Can be caused by mining activities or, more commonly in the south-east, clay shrinkage or subsoil failure.
Sub-soil – Soil lying immediately below the top-soil.
Sulphate Attack – Chemical reaction, activated by water, between tricalcium aliminate and soluble sulphates which can cause deterioration in brick walls and concrete floors.
Tell-tale – Gauge fixed over crack to monitor movement in wall.
Tie Bar – Metal bar passing through the wall, or walls, in an attempt to brace a structure suffering from structural instability.
Tingle – A strip of flexible metal used to hold a replacement slate in position on a roof.
Trada – Timber Research and Development Association.
Trap – A U-shaped bend in a waste pipe forming seal to prevent foul air escaping from the pipe.
Torching – Mortar applied on the underside of roof tiles or slates to help prevent moisture penetration. Not necessary when a roof is under drawn with felt.
Transom – Horizontal bar of wood or stone across a window or top of door.
Tread – The horizontal part of a step or stair.
Trimmer Joist – A Short timber which encloses one side of a rectangular hole in a floor or ceiling, such as that found around a loft hatch or stairway.
UPVC – (Unplasticised polyvinyl chloride) A fairly stiff plastic material form which rainwater gutters and other building components are often made.
Floors: Necessary to avoid rot, especially dry rot; achieved by air bricks near to the ground level.
Roofs: Necessary to disperse condensation within roof spaces; achieved either by air bricks in gables or ducts at the eaves.
Wainscoting – Material used to make wainscote.
Wall Plate – Timber placed at the eaves of a roof, designed to take the weight of the roof timbers and coverings
Wall Tie – A twisted piece of metal or similar material bedded into the inner and outer leaves of cavity walls to strengthen the wall. Failure by corrosion can result in the wall becoming unstable – specialist replacement ties are then required.
Waste Pipe – A pipe from a wash hand basin, sink or bath to carry away the waste water into the drains.
Weather Boarding – Horizontal overlapping boards nailed on the outside of a building to provide the finished wall surface.
Weep Holes – Allow drainage from wall cavity and dry conditions caused by fungi. Less difficult to eradicate than dry rot.
Wet Rot – (Coniophora Puteana). Decay of timber due to damp conditions. Not to be confused with the more serious dry rot.
Woodworm – Colloquial term for beetle infestation: usually intended to mean Common Furniture Beetle (Anobium Punctatum): by far the most frequently encountered insect attack in structural and joinery timbers.