An A to Z of building terminology
Aggregate
The collective term for gravel, sand and stone, which can be used to make concrete.
Architrave
Joinery moulding around a window or doorway.
Ashlar
Finely dressed natural stone: the best grade of masonry. Ashlar blocks are large rectangular blocks of masonry sculpted to have square edges and even faces. The blocks are generally 13 to 15 inches in height. They are used in the construction of many old buildings as an alternative to brick.
Asphalt
Black, tar-like substance often used on flat roofs and floors.
Banker mason
Carves and shapes the stone on the bench and gives it a textured or polished finish using hand and power tools.
Breeze Block
Originally made from cinders (‘breeze’) the term is now commonly used to refer to various types of concrete and cement building blocks.
Cavity Wall
Standard modern method of building external walls of houses comprising two leaves of brick or blockwork separated by a cavity of about 50mm (2 inches).
Cavity Wall Insulation
Filling of wall cavities using polystyrene beads, foam or rockwool.
Coping/Coping Stone
Usually stone or concrete, laid on top of a wall as a decorative finish and to stop rainwater soaking into the wall.
Corbell
Projection of stone, brick, timber or metal jutting out of a wall to support a weight.
Cornice
Ornamental moulded projection around the top of a building or around the wall of a room just below the ceiling.
Damp Proof Course
Layer of impervious material (mineral felt, pvc etc) incorporated into a wall to prevent dampness rising up the wall or lateral dampness around windows, doors etc.
Devon bank
Originating in Devon, walling with soil giving added weight and stability.
Dormer
Structural element of a building that protrudes from the plane of a sloping roof surface. Dormers are used, either in original construction or as later additions, to create usable space in the roof of a building by adding headroom and usually also by enabling addition of windows.
Dry Rot
Fungus that attacks structural and joinery timbers, often with devastating results. It often flourishes in moist, unventilated areas.
Eaves
Overhanging edge of a roof.
Engineering Brick
Particularly strong, dense brick, sometimes used for damp-proof courses.
FMB
Federation of Master Builders, the largest trade association in the UK building industry representing over 13,000 building companies.
Fibreboard
Cheap, lightweight board material used in ceilings or as insulation to attics.
Flashing
Building technique used to prevent leakage at a roof joint. Normally metal (lead, zinc, copper) but can be cement or felt.
French drain
Ditch filled with gravel or rock that redirects surface and ground water away from an area. A common drainage system primarily used to prevent ground and surface water from penetrating or damaging building foundations.
Geothermal heat pump
Uses the relatively constant temperature of the earth to heat and cool homes typically with 40 – 70% less energy consumption than conventional systems.
Gully
An opening into a drain, normally at ground level, placed to receive water etc. from down pipes and waste pipes.
Hip
The external junction between two intersecting roof slopes.
IOC
Institute of Carpenters, an affiliate of The Worshipful Company of Carpenters, the only organisation to offer practical and theoretical examinations in woodworking skills and supervisory and management techniques on an annual basis.
Jamb
Side part of a doorway or window.
Joist
Horizontal structural timber used in flat roof, ceiling and floor construction.
Lath
Thin strip of wood used in the fixing of roof tiles or slates, or as a backing to plaster. Lath and plaster walls were very common in houses from the late 1800s to the1950s.
Limecrete
Lightweight, breathable, self-insulating ecological alternative to cement-based concrete.
Lintel
Horizontal structural beam of timber, stone, steel or concrete placed over window or door openings.
Mortar
Mixture of sand, cement, lime and water, used to join stones or bricks.
Mullion
Vertical bar dividing individual lights in a window.
Pointing
Smooth outer edge of mortar joint between bricks and stones etc.
Purlin
Horizontal beam in a roof upon which rafters rest.
Quoin
The external angle of a building; specifically the bricks or stone blocks forming that angle.
Rafter
A sloping roof beam, usually timber, forming the carcass of a roof.
Rendering
Vertical covering of a wall either plaster (internally) or cement (externally), sometimes with pebbledash, stucco or Tyrolean textured finish.
Soakaway
Arrangement for disposal of rainwater, utilising graded aggregate laid below ground.
Soaker
Sheet metal (usually lead, copper or zinc) at the junction of a roof with a vertical surface of a chimneystack.
Subsidence
Ground movement, generally downward, possibly as a result of mining activities or clay shrinkage.
Trussed Rafters
Method of roof construction using a prefabricated triangular framework of timbers, now widely used in domestic construction.
Underpinning
Method of strengthening weak foundations whereby a new, stronger foundation is placed beneath the original.
Valley Gutter
Horizontal or sloping gutter, usually lead-or-tile-lined, at the internal intersection between two roof slopes.
Ventilation
Necessary in all buildings to disperse moisture resulting from bathing, cooking, breathing etc. and to assist in prevention of condensation.
Verge
Edge of a roof, especially over a gable.
Wall Plate
Timber placed at the eaves of a roof to take the weight of the roof timbers.
Wet Rot
Decay of timber due to damp conditions. Not to be confused with the more serious Dry Rot.
Woodworm
General term for beetle infestation usually intended to mean the Common Furniture Beetle, by far the most frequently encountered insect attack in structural and joinery timbers.
