Glossary of Basic Construction Terms

Aggregate

Coarse material such as crushed stone, gravel, sand etc used to mix into concrete, laying beneath paving or foundations.

Architrave

The frame around a door or window.

Backfill

Refilling a hole in the ground with material that was previously dug out of it. For example: after stormwater drains are laid into trenches, previously excavated soil is placed on top of the pipes as backfill.

Balustrade

A railing (consisting of a horizontal handrail and vertical balusters), for example surrounding a balcony or stairs.

Barge board

Wide board (usually timber) attached to ends of roofing elements to protect and conceal them from weather and view.

Beam

Horizontal structural element.

Brick veneer

A layer of bricks on the outside of the building which is for cladding purpose only - it does not support the weight of the building. (Most New Zealand houses with brick on the outside are brick veneer - the inside is held up by timber framing.)

CAD (computer-aided design)

Computer software used by architects, engineers and others to create precision drawings or technical illustrations.

Cavity (wall)

Gap left intentionally between exterior cladding (such as brick) and interior (such as timber framing) to reduce the amount of moisture moving from outside of the building to the inside.

Cladding

A layer of material protecting elements beneath it, for example, corrugated iron sheets are cladding on roofs, bricks are cladding on walls.

Column

Vertical structural element.

Design-build

When the company who provides design services is the same that will construct the building.

Dwangs (a.k.a nogs or blocking)

Horizontal pieces of timber framing used between vertical studs to provide the wall with rigidity.

Eave

Edges of the roof overhanging the face of a wall.

Elevation

Synonym for the facade, side view of the building, as opposed to "plan" which is a top view. "North elevation" therefore means "view of the building from the north".

Expansion joint

Line of separation between two adjoining elements that provide with space to move in response to temperature, earthquake, wind etc without damaging the material itself. Very common in concrete.

Fascia

Board (usually timber) attached to the bottom of roof rafters - it provides a flat surface onto which drains for stormwater (ie spouting) can be attached.

Foundation

The lower part of the building - it transfers the weight of the building onto the ground below. Most commonly concrete slab or timber piles.

Formwork

Mould into which concrete is poured.

Framing

Fitting together of pieces to give structure support and shape. Most commonly timber, but can also be steel.

Gable

Triangular part of the wall at the end of (or under) a ridged roof.

HVAC

Short for heating, ventilation & air conditioning.

Insulation

Material that prevents heat (or sound, or electricity - depending on function) spreading from one building element onto another.

Joinery

Building elements constructed by a joiner (rather than a carpenter/builder) such as cabinetry, doors, built-in shelving etc.

Joist

Horizontal element supporting floor or ceiling (usually made of timber or steel).

Load-bearing wall

Wall that supports the weight of other building elements above it and, therefore, cannot be removed without putting other support mechanisms in place (otherwise it would risk the collapse of building above it).

Masonry

Stonework such as bricklaying.

Moisture barrier (a.k.a vapour barrier)

The material used to prevent moisture moving from one building element to another. For example polythene sheet under concrete, or bitumen on the roof.

Penetrometer testing

The method used to test ground conditions by dropping a specific weight onto it. (In soft soil, the weight penetrates the ground much easier than in the hard ground.)

Pile

Type of foundation where series of long posts (timber, steel or concrete) are dug into the ground to support the weight of the building. (Random fact: Venice in Italy is built almost entirely on piles.)

Plant

Another word for (large) tools, equipment and machinery.

Plasterboard

Board (commonly used on walls and ceilings) that is made of plaster and covered on both sides with heavy paper. Usually painted afterwards.

Plywood

Board made of thin sheets of timber glued together. Each layer is called "ply": 9-layer plywood is a "9-ply". Commonly used on walls, ceilings and beneath floors.

Precast concrete

Concrete (usually wall panel or floor) that's manufactured entirely in a factory and then transported to the building site to lift in place (rather than pouring it on the building site itself).

Purlin

A horizontal beam along the length of a roof, either below rafters (under purlin) or on top of them.

PVC

Short for polyvinyl chloride - a type of plastic commonly used for pipes and windows.

Rafter

Main support structure holding up a roof and giving it a common triangular shape.

Reinforcing

Steel embedded inside concrete to give it strength, usually in the shape of rods, bars and mesh.

Sarking

Timber panels attached to the roof surface, so that roofing tiles can be nailed directly onto it. Can also mean waterproof building material under roof tiles; or a 19th-century construction technique of attaching timber panels inside wall and ceilings, so that wall coverings had a flat surface to attach to.

Scaffolding

The temporary structure on the outside of a building, made of wooden planks and metal poles, used by workmen while building, repairing or cleaning the building.

Services

Another word for plumbing, electrical, heating etc - systems used to make a building comfortable, functional and safe.

Skirting

Moulding in the bottom of a wall to cover the joint between floor and wall.

Soffit

Under-surface of something: most commonly, soffit is used to refer to the underside of roof eaves.

Stopping

Filling of small blemishes (scratches, nail holes, gaps) in a surface that's about to be painted, for example, plasterboard.

Stud

A vertical member in wall framing, between floor and ceiling.

Takeoff

Another word for measurement - counting and measuring of construction elements (floor area, doors, timber framing etc) from architectural plans so an accurate estimate can be put together.

Truss

In construction, the truss is a common word for a partially pre-fabricated roof structure which can be assembled on-site (rather than building the entire roof on-site).

Weep hole

The small opening left in brickwork to allow moisture to drain out and ventilation to get in behind bricks.