A handy reference guide to common building and plumbing terms you may come across in your inspection report or during the construction process.
AG LINE A perforated pipe, typically wrapped in geo-textile fabric, installed behind retaining walls and similar structures to collect and redirect seeping stormwater away from the building.
ARCHITRAVE Decorative trim fixed around the edges of a door or window frame to neatly conceal the gap between the frame and the surrounding wall surface.
BAGGING A brickwork finish applied by working a thin cement slurry into the surface using a hessian bag or sponge. It can be painted or left with an oxide finish and varies considerably in texture and colour, unlike the uniformity of render.
BALUSTRADE A row of upright posts or spindles that support a handrail along stairs, landings, platforms or bridges.
BEARER A horizontal structural timber in the sub-floor system that sits above the stumps or piers and provides support for the floor joists above.
BRICK VENEER A construction method where a single, non-load-bearing skin of brickwork is tied to an internal timber or steel frame. The frame carries the structural loads while the brickwork forms the outer wall cladding.
CEMENT A finely milled inorganic powder that, once combined with water, binds sand and aggregate into hard concrete or mortar as it cures over several days.
CONCRETE An artificial stone-like material formed by combining cement, water and aggregates in set proportions, then pouring the mix into prepared formwork where it sets and hardens.
CORNICE A decorative moulding fitted at the junction where the wall meets the ceiling.
DADO The lower section of an interior wall, from the skirting board upward, when it is finished differently to the upper portion — for example, with timber panelling or a contrasting paint colour.
DAMP-PROOF COURSE (DPC) A continuous layer of impervious material built into a masonry wall or positioned between a floor and wall to block the upward or downward movement of moisture through the structure.
EAVES The section of a roof that extends beyond the outer walls of the building, providing a degree of weather protection to the walls below.
FASCIA A board or metal profile fixed to the lower ends of the roof rafters that typically carries the guttering.
FINIAL An ornamental fitting placed at the junction of roof ridges and hips, or at the peak of conical, pyramid or dome-shaped roofs.
FOOTING The structural base of a building, usually constructed from reinforced concrete, designed to spread the building’s load into the ground and support the base brickwork or slab above.
FOUNDATION The natural or prepared ground — whether soil, sub-soil or rock — upon which a building’s footings bear and transfer load.
FURRING CHANNEL Lightweight metal battens fixed to the underside of trusses, rafters or ceiling joists to create a flat, level surface for attaching ceiling linings.
GABLE The triangular portion of an end wall on a pitched-roof building, extending from eaves level up to the ridge. It may be constructed in brick or as a timber-framed wall clad with weatherboards.
GAUGE In brickwork, a measurement standard indicating how many brick courses fall within a given height, for example, seven courses per 600mm. The gauge is adjusted to suit the specific brick size and site conditions.
GIRDER TRUSS A truss running perpendicular to the standard roof trusses, fitted with bracket connections (shoes) to carry and support the adjacent trusses. It is often doubled up or incorporates hardwood elements to handle the additional load.
GOING In staircase construction, the horizontal measurement from the face of one riser to the face of the next.
HANGING BEAM A beam positioned above the ceiling line, used to carry and support ceiling joists from above.
HEAD The top horizontal member of a door or window opening or frame.
HEADER A brick laid with its longest dimension running across the width of the wall, commonly used to tie two wall skins together or to form a solid course beneath windowsills or door thresholds.
HEARTH The floor area inside a fireplace and the immediately surrounding area in front of it.
HERRINGBONE BOND A brickwork pattern in which bricks are laid diagonally to create a repeating series of V-shapes or inverted V-shapes.
HIP The external ridge line formed where two sloping roof surfaces meet at an outward angle.
HIP ROOF A roof style that slopes on all four sides, with no vertical gable ends, creating a pyramid-like form with level edges all around.
HOOP IRON STRAP A thin strip of steel, typically around 25mm wide, embedded into brickwork or nailed to framing members to act as a wind tie-down.
IN-FILL CONCRETE SLAB A concrete slab poured between base brick walls that are themselves supported on concrete footings. The slab sits on compacted fill or temporary formwork.
JOIST A horizontal timber or steel beam that spans between bearers and provides the direct fixing surface for flooring above.
KING POST A vertical structural member running from the ridge down to the tie beam in a roof truss.
LAMINATE A composite material formed by bonding two or more layers together under pressure.
MELAMINE LAMINATE A durable laminate made from compressed layers of paper, textile, plastic or wood veneer set in melamine resin. Commonly used as a shelf and cabinet surface in kitchens and wardrobes.
LINTEL A horizontal structural member that spans across a door or window opening to carry the load of the wall above. A ‘galintel’ refers specifically to a steel lintel used to support brickwork over an opening.
MORTAR A workable mixture of sand, cement and water used to bed and joint brickwork. A standard mix is typically six parts sand to one part cement, sometimes with lime added. Joints can be finished flush, raked or rounded.
NEWEL POST The main post at the top or bottom of a staircase that anchors and supports the handrail.
NOGGING A short horizontal timber fixed between studs, joists or trusses to add rigidity or provide a fixing point for wall or ceiling linings.
NOMINAL SIZE A convenient description used to refer to timber dimensions that does not represent the exact finished size, particularly before the timber has been dressed.
PARAPET A low protective wall running along the edge of a roof, balcony or terrace. On commercial buildings, a parapet at the front facade often provides a surface for signage.
PARTICLE BOARD A flat sheet material made from wood particles and synthetic resin bonded together under heat and pressure. It offers good dimensional stability and is used for flooring and joinery.
PELMET A fixed timber or board housing installed above a window or sliding door to conceal the curtain rod or door track.
PERP A vertical mortar joint in masonry construction.
PITCH ROOF The slope of a roof expressed as a ratio of height to span, usually stated in degrees.
PICTURE RAIL A timber or plaster moulding fixed to the wall at or above door height, used for hanging pictures or as a decorative feature.
PLYWOOD A sheet material built up from thin layers of timber veneer laid at right angles to each other and glued together under heat and pressure. Used in flooring, wall bracing, cladding and formwork.
POINTING The process of finishing or repairing mortar joints in brickwork or bedding and jointing ridge and hip tiles on a roof.
ACROW PROP A lightweight, typically adjustable steel prop used in scaffolding or as temporary support for beams and slabs during construction or repairs.
QUAD MOULDING A small moulding with a quarter-circle cross-section used to cover and finish the joint at the junction of walls, ceilings or eaves.
RAFTER A sloping structural roof member that runs from the ridge down to the eaves, providing the primary support for the roof cladding.
RAFTER (COMMON) A standard rafter that spans the full distance from the eaves to the ridge without interruption.
RAFTER (CRIPPLE) A short rafter that connects a hip rafter to a valley rafter.
RAFTER (GABLE) A common rafter positioned at the gable end of a pitched roof.
RAFTER (HIP) The rafter that runs diagonally along the hip of a roof, where two sloping surfaces meet at an outward angle. Jack rafters frame into it on both sides.
RAFTER (JACK) A shortened rafter spanning between a ridge and a valley, or between a hip rafter and the eave.
RAKED JOINT A brick mortar joint that has been deliberately recessed by the bricklayer, either to create a key for plastering or as a decorative finish.
RENDER A coating applied to a masonry wall using one or more coats of cement mortar — typically a mix of sand, cement and plasterers clay.
RIDGE The uppermost horizontal line of a pitched roof, running along the apex where the two sloping sides meet.
RISER The vertical face of a step in a staircase.
SCISSOR TRUSS A roof truss with a sloping bottom chord that creates a raked internal ceiling, offering a cost-effective alternative to individually cut rafters.
SCOTIA A concave decorative moulding, typically used as a trim piece.
SEASONING The controlled removal of excess moisture from timber through air drying or kiln drying prior to use.
SHIPLAP Timber boards that have been rebated along each edge so that adjacent boards lap over one another, forming a weathertight cladding.
SHORING Temporary or permanent propping of an existing structure to prevent movement or collapse, typically used during excavation works or demolition of adjacent buildings.
SKEW NAILING A fixing technique in which nails are driven at an angle, often in opposing directions, to increase the strength and rigidity of a timber joint.
SKIRTING A board fixed along the base of a wall at the floor junction to protect the wall from damage and conceal any gap between the wall lining and the floor.
SLIP JOINT A joint designed to allow controlled movement between two structural elements, typically formed using two layers of sheet metal with grease, installed on top of a masonry wall before a concrete slab is poured.
SOFFIT The underside of a structural element such as a concrete slab, beam or roof eave.
SOLDIER COURSE A course of brickwork where the bricks are stood on end with the narrow face visible.
SPROCKET A short timber piece used in eaves framing, typically to reduce the pitch of the roof at the eave for improved aesthetics or water runoff.
STRETCHER BOND The most widely used masonry bond in Australia, in which all bricks are laid lengthways with half-brick overlaps between courses.
STUCCO Traditionally an ornamental external render finish; in modern usage, often refers to a fibrous cement sheet product with a textured decorative surface.
TERRAZZO A hard flooring material made from marble or stone chips set in a cement matrix, which is then cast, ground and polished to produce a smooth, durable surface.
THRESHOLD The sill or step at the base of an external door opening, typically constructed from timber, tile or brick.
TOUGHENED GLASS Safety glass produced by rapid cooling during manufacture, causing it to shatter into small, relatively harmless pieces when broken. It cannot be cut on site and must be ordered to the required size. This differs from laminated glass, which uses silicon-bonded layers to hold together when cracked.
TRIMMER A short timber member fixed between joists or framing members to stiffen the structure or provide a fixing point for linings and finishes.
UNDERPINNING The construction of new footings or concrete piers beneath an existing foundation to stabilise or strengthen it where the original footing has failed or is at risk of doing so.
VALLEY The internal angle formed where two sloping roof surfaces meet, directing rainwater down toward the guttering.
WEEP HOLES Open vertical joints or perpends left in brickwork above the flashing line to allow any water that has penetrated behind the wall to drain freely to the outside.
WINDERS The wedge-shaped treads used in a staircase where the flight changes direction within the landing area.
Z-PURLIN A steel purlin with a Z-shaped cross-section used to support roof sheeting in steel-framed buildings.
ABSORPTION TRENCH A trench or pit excavated into permeable ground and filled with coarse material such as broken stone or gravel, then covered with soil. Used to dispose of effluent from a septic tank or stormwater system by allowing it to gradually soak into the surrounding ground. Also referred to as an absorption pit, absorption well or soakaway.
GULLY TRAP (GT) A drainage fitting that incorporates a trap and associated components within a sanitary drainage system. Also simply called a gully.
FLOOR WASTE GULLY A disconnector gully fitted with a floor grate inside a building, allowing wastewater to drain away and, where required, accepting connections from sanitary fixtures.
INVERT The lowest point of the internal surface of a pipe or drainage channel at any given cross-section.
JUNCTION (PIPE) A pipe fitting that incorporates one or more branch connections.
MANHOLE An access chamber constructed on a drain or sewer to allow inspection, testing and clearing of blockages.
STACK A vertical drainage pipe, including any offsets, that extends through more than one storey of a building.
SULLAGE Household wastewater generated from sources other than toilets — for example, from sinks, showers and laundry fixtures.
SUMP A pit located at or below the lowest point of a structure to collect unwanted water for removal, usually via a sump pump. Also called a drain pit.
TRAP A fitting — usually P- or S-shaped — that holds a small amount of water to form a seal preventing foul gases from entering the building through the drainage system. Also refers to a fitting designed to intercept silt, grease, oils or fats before they enter the drain.
BOUNDARY TRAP A trap installed in the property drainage line, typically near the property boundary, to prevent sewer gases from entering the building’s drainage system. Also called an interceptor trap.
GREASE TRAP A baffled chamber installed in a drainage line to slow the flow of liquid waste and capture greasy substances before they enter the sewer. Also called a grease interceptor trap.
P-TRAP A trap where the inlet is vertical and the outlet leg angles below horizontal, with an optional inspection opening at the base.
S-TRAP A trap where the outlet leg is vertical and runs parallel to the inlet, with an optional inspection opening at the lowest point.
SILT TRAP A trap fitted with a removable container that collects silt, sand or grit from wastewater before it enters the drain.
VALVE A device used to control the flow of liquid or gas through a pipe, using a movable disc, gate, ball or diaphragm to open or restrict the aperture.
BALL VALVE A flow control valve that uses a rotating ball with a bore to open or shut off the passage of fluid.
FLOAT VALVE A valve controlled by a floating ball that rises and falls with the water level in a tank or cistern, automatically shutting off the water supply when the set level is reached. Also called a floating ball valve.
FLUSH VALVE A mains-pressure flow control device fitted to a toilet pan in place of a cistern.
GATE VALVE A water control valve that operates by sliding a gate across the pipe opening to stop or permit flow.
MIXING VALVE A valve designed to combine hot and cold-water supplies and deliver a blended flow at a controlled temperature.
NON-RETURN VALVE A valve that allows flow in one direction only, preventing backflow by means of a flap or similar mechanism. Also called a check valve.
PRESSURE REDUCING VALVE A valve that limits or reduces the water pressure on the downstream side of the fitting to a set level. Also called a pressure limiting valve.
PRESSURE RELIEF VALVE An automatic valve, spring-loaded or weighted, that opens to release excess pressure from pipework or vessels to the atmosphere before unsafe levels are reached.
SAFETY VALVE A pressure relief valve specifically designed for boilers or unfired pressure vessels.
STOP VALVE A valve such as a gate valve that can be operated to fully stop flow in a pipeline. Also referred to as an isolating valve.
TEMPERATURE RELIEF VALVE A temperature-activated valve that releases pressure from a hot water system if the thermostat fails and the water overheats.
VENT (VENT PIPE) A pipe connected to a drainage system that vents to the atmosphere, preventing pressure fluctuations within the drain lines and allowing foul gases to escape safely.
TRAP VENT A vent pipe connected from an individual trap to the open air or to a main vent stack, preventing the water seal in the trap from being siphoned away. Also called an anti-siphonage vent or back vent.
