Construction Jargon Buster

Abutment – Where a roof meets a wall.

Aggregate – Crushed stone, gravel or sand mixed with cement to make concrete.

Airbrick – Ventilated brick allowing air under floors or into roof spaces.

Architrave – Decorative trim around a door or window.

Asbestos – Older insulation or fireproofing material; safe if untouched, hazardous if cut or drilled.

Ball Valve / Ballcock – Float valve controlling water flow into a cistern or tank.

Balustrade – Rail with posts beneath, beside stairs or balconies.

Batten – Thin timber strip supporting roof tiles or slates.

Bonnet Tile – Curved tile covering roof hips.

Casement Window – Window with hinged, pivoted or fixed sections.

Cladding – Non-structural outer wall or roof covering.

Conduit – Tube protecting electrical cables.

Consumer Unit – Main fuse board controlling a home’s electrical circuits.

Coping Stone – Cap on top of a wall to prevent water ingress, often concrete or stone.

Cornice / Coving – Moulded trim at the junction between a wall and the ceiling.

Cowl – Chimney cap preventing rain and allowing airflow.

Dado Rail – Mid-height wall trim or top of panelling.

Engineering Brick – Dense, hard brick used for strength or damp resistance.

Expansion Tank – Small loft tank allowing heating system overflow.

Fascia Board – a long, straight board that runs along the lower edge of a roof where it meets the exterior wall.

Flashing – Waterproof joint between a roof and wall.

Flue – Channel for air intake and fume outlet from fires or boilers.

Macerator – Aa device that grinds up waste and then pumps it through pipes to a drainage system.

Mastic – Flexible sealant used around joints or glazing.

Mortice Lock – Lock set into the edge of a door.

Newel – Main post supporting a stair handrail.

Padstone – Concrete or hard brick block used to spread weight from structural elements like steel beams.

Plasterboard – Sheet of plaster between paper layers used for walls or ceilings.

Plywood – Multi-layer board made from thin sheets glued with alternating grain.

Rodding Eye – Access point for clearing drain blockages.

Soffit – Underside of a roof overhang, beam or stair.

Soil Stack – Vertical waste pipe vented above roof.

Stopcock – Valve to shut off a water or gas supply.

Trap – U-shaped bend in waste pipes holding water to block smells.

Benching / Haunching – Shaped concrete at the base of a drain chamber.

Bond – Brick or block laying pattern (e.g. English, Flemish).

Box Gutter – Square gutter behind a parapet wall.

Cold Roof – Roof where insulation sits below the structure.

Condensation – Water released by condensed moist air.

Course – Single horizontal layer of bricks, blocks or slates.

Damp-Proof Course / DPC – Waterproof layer in a wall stopping rising damp.

Damp-Proof Membrane – Waterproof sheet beneath floors or slabs.

Distemper – Old chalk-based paint finish.

Dormer Cheek – Side wall of a dormer window.

Drip – Groove stopping rainwater running down a wall.

Dry Rot – Wood fungus found in damp, unventilated areas.

Eaves – Lower overhang edge of a roof.

Foundations – Concrete base supporting a building.

French Drain – Gravel trench draining water from walls.

Frog – Hollow in a brick’s top face to save weight.

Gable – Triangular end wall of a pitched roof.

Heat Exchanger – a device which transfers heat between incoming (fresh) air and outgoing (humid) air.

Hip – Sloping junction where roof faces meet.

Hopper – Funnel head directing rainwater into downpipes.

HVAC – heating, ventilation, air conditioning: systems that control building’s temperature, humidity & air quality.

Inspection Chamber – “Manhole” giving access to underground drains.

Joist – Horizontal beam supporting a floor or ceiling.

Kerb – Raised edge on a flat roof beside a wall.

Lath – Narrow slats traditionally used as a base for plaster.

Lintel – Beam over an opening supporting wall above.

Load-Bearing – Structure carrying the weight above it.

Mullion – Vertical divider between window panes.

Oversite – Rough concrete layer below timber floors.

Parapet – Low wall at the edge of a roof or balcony.

Pier – Vertical column strengthening or supporting a wall.

Pointing – Finished mortar joints between bricks.

Purlin – Horizontal roof beam supporting rafters.

Rafter – Sloping timber forming the roof frame.

Reveal – Side face of a window or door opening.

Ridge – Apex or highest point of a roof.

Riser – Vertical part of a stair step.

Rising Damp – Moisture drawn up walls from the ground.

Roof Deck – Base boarding under a flat roof covering.

RSJ – Rolled Steel Joist, a stiff structural beam.

Screed – Smooth top layer over a concrete floor.

Scrim – Mesh tape covering plasterboard joints.

Soakaway – Underground pit letting rainwater soak into the ground.

String – Side of a staircase supporting treads and risers.

Stud Partition – Lightweight internal wall.

Transom – Horizontal divider in a window or above a door.

Tread – Flat step surface on stairs.

Trussed Rafters – Prefabricated triangular roof frames.

Underpinning – Used to strengthen weak foundations

Verge – Edge of a sloped roof over a gable.

Ventilation – Airflow preventing condensation and decay.

Wall Plate – Horizontal timber supporting joists.

Warm Roof – Roof with insulation above the structure.