Glossary

Glossary

Abutment
Architrave
Baffle
Ball valve
Bargeboard
Battens
Beam
Bund
Canopy
Casement window
Cesspit
Cistern
Clom
Combi boiler
Coping
Corbel
Corbelling
Cornice
Crown glass
Cylinder glass
Defrassing
Distemper
Dormer window
Eaves
Fanlight
Fascia board
Finial
Fire hood
Flaunching
Flue
Flue liner
Frass
Gable end
Gauged brickwork
Geotextile membrane
Glass quarries
Gully
Gypsum plaster
Hip
Hopper head
Hygroscopic salts
Joists
Laths
Lead cames
Lead flashing
Leaded lights
Lime mortar
Lime pargeting
Limewash
Mortar fillet
Mortice and tenon
Nibbed tile
Ogee profile guttering
Parapet
Parting bead
Patination oil
Pendant
Pinnings
Pintles
Pitched roof
Pointing
Proprietary clips
Pulley stile
Purlins
Render
Ribbon pointing
Ridge
Roof grouting
Roof trusses
Roofing felt
Rooflight
Sash window
Scarf joints
Septic tank
Soffit
Spalling
Sprigs
Stiles
Tanking
Thermal bridge
Tingle
Torching
Tuck pointing
Verge
Wallhead
Wattle and daub

Abutment

The junction between a roof and a rising wall.

Architrave

An often decorative piece of wood that covers the gap between a window frame or door and the wall.

Baffle

A chimney baffle is a strip of sheet metal which ensures gases and smoke flow up through the chimney and do not re-enter a room.

Ball valve

In a water tank or cistern, the ball valve, or ballcock, shuts off the water supply when the water level reaches about an inch (25mm) below the level of the overflow outlet.

Bargeboard

A sometimes decorative board fastened to the projecting gable of a roof for strength and protection. Sometimes called a verge board.

Battens

In roofing the battens are thin strips of wood stretching across the length of the roof, onto which roof tiles or slates are fixed.

Beam

A horizontal load-bearing structural member, made of timber, steel or concrete.

Bund

Material, usually concrete or masonry, surrounding water or oil tanks and pipes to prevent leaks and spillage.

Canopy

An overhanging roof-like projection that provides shelter.

Casement window

A window attached to its frame by hinges.

Cesspit

A sealed underground tank for temporary storage of waste water which requires regular emptying.

Cistern

A tank holding water for use in toilets, showers, sinks, etc.

Clom

A type of wall made of unbaked earth, consisting of a sub-soil containing clay mixed with other materials such as straw or coarse animal hair.

Combi boiler

A boiler that both heats water and provides central heating without the need for a separate water cylinder.

Coping

A protective capping or covering to a wall, gable, parapet or balustrade.

Corbel

A block of masonry or wood that projects from the face of a wall to support elements above it, such as a beam.

Corbelling

A series of masonry or brick courses, each built out beyond the one below. Often seen on chimneys.

Any horizontal moulded projection that crowns or finishes the part of the building to which it is fixed, such as at the top of an external wall beneath the eaves. Also, the decorative plaster or timber moulding between the wall and ceiling of principal rooms, as commonly found in Georgian town houses.

Crown glass

A type of window glass used exclusively up until the mid-nineteenth century. It was produced by blowing a bubble of molten glass, which was then attached to a solid metal rod, called a ‘pontil.’ The glass was re-heated and spun to form a disk of glass up to 5ft (1.5m) wide. After cooling, the glass was cut to size.

Cylinder glass

An alternative to crown glass from the mid-nineteenth century onwards. It is produced by blowing a cylinder-shaped bubble of glass, which can be up to 5ft (1.5m) long and 12ins (30.5cm) wide. The ends are removed, and the cylinder cut lengthways and opened out to produce a flat sheet of glass. Panes could be much larger than with crown glass, overcoming the need for glazing bars.

Defrassing

The removal of powdery material on the surface of timber.

Distemper

An old form of paint made from whiting and glue.

Dormer window

A window which project through a sloping roof.

Eaves

Made up of both the soffit and the fascia, the eaves project beyond the wall on the lower edge of a roof and hold the guttering.

Fanlight

The fixed glazed panel above the main entrance door of a building.

Fascia board

A horizontal trim fixed to the ends of the roof rafters.

Finial

The ridges of Victorian buildings, in particular, often have decorative carvings projecting above the gable ends or where the ridge meets the hip. They are sometimes made of clay, especially on hipped roofs, but on gabled roofs they are more frequently of squared or turned timber.

Fire hood

A metal canopy installed over an open fire to prevent smoke from blowing into the room and to improve the draw.

Flaunching

A sloping mortar fillet applied at the top of a chimney stack to hold the pots in place and to help shed water.

Flue

A duct, pipe or chimney which channels exhaust fumes, smoke, etc, from a fireplace or boiler to the outside of a house.

Flue liner

A fireproof material that lines the flue.

Frass

Fine wood dust. (see Defrassing).

Gable end

The usually triangular portion of a wall between the edges of a sloping roof.

Gauged brickwork

Bricks which are sawn and rubbed into precise shapes to produce neat arches over door and window openings.

Geotextile membrane

Permeable or non-permeable artificial fabric used in filtration, drainage, tree root protection, weed control, etc.

Glass quarries

Small, square piece of glass, usually set diagonally, within a window.

Gully

A small trench, usually formed in concrete, to carry water away from a building.

Gypsum plaster

A fast setting plaster made by heating gypsum rock or alabaster, and commonly known as plaster of Paris. Used to produce fibrous plaster mouldings from the mid-nineteenth century. Modern gypsum plaster often has a waterproofing agent added to it. It is not a suitable substitute for lime plaster.

Hip

A hip roof is where all sides slope down towards the walls.

Hopper head

An open-topped funnel placed on top of a downpipe to collect rainwater from more than one outlet.

Hygroscopic salts

Salts which form on wall surfaces, absorbing any moisture present in the atmosphere.

Joists

Parallel wall-to-wall timber beams which support a ceiling or floorboards

Laths

Thin strips of wood, either riven or sawn. They are nailed a little distance apart to the studs of a timber framed wall, or onto the underside of floor joists or rafters to form a framework onto which lime plaster or render is applied.

Lead cames

Lead strips, often 'H' shaped, that hold the pieces of glass together in a leaded light.

Lead flashing

Lead sheeting used to protect the join of a vertical surface and a roof from rainwater.

Leaded lights

A window containing panes of glass arranged in a pattern between lead cames (see Lead Cames).

Lime mortar

One of the oldest forms of mortar, used to bind construction blocks, composed of lime, an aggregate such as sand, and water. Unlike modern cement, it is breathable and slightly flexible, making it particularly suitable for buildings of traditional construction.

Lime pargeting

Ornamental plasterwork made from lime. Also the term given to the lime plaster lining of a flue.

Limewash

Lime wash is lime putty that has been watered down for easy application applied to various surfaces for extra protection.

Mortar fillet

Lime or cement mortar applied at an abutment to prevent water from getting into the building.

Mortice and tenon

Where the end of one timber is inserted into a hole cut in the other.

Nibbed tile

Nibbed roof tiles have small lumps of clay at the top edge, which can be hooked over battens like pegs. They also have holes to allow them to be nailed to the battens in exposed locations.

Ogee profile guttering

Ogee guttering has a flat back and is supported on a projecting eaves course of brick or stone, or screwed directly to the wall or a timber fascia board.

Parapet

A wall built on the edge of a roof, terrace or balcony.

Parting bead

A vertical strip that separates the sashes of a sash window.

Patination oil

A white spirit-based oil that helps prevent staining from newly-fitted lead running onto nearby materials.

Pendant

Decorative carvings on gable ends sometimes extend downwards, the lower section being known as a ‘pendant.’

Pinnings

Pinnings, made of stone offcuts and chippings, were traditionally used in masonry to level up individual stones and courses and to save on mortar.

Pintles

A pin or bolt which forms the pivot of a window hinge.

Pitched roof

A pitched roof is made up of two sloping surfaces which meet in the middle with gables at either end (see Gable end).

Pointing

Mortar joints between masonry blocks.

Proprietary clips

Clips used in the repair of slate roofing tiles.

Pulley stile

The upright of a window frame into which sash pulleys are installed and along which the sash slides.

Purlins

Horizontal timbers running the length of a building’s roof.

Render

Most commonly used to describe the coats of lime or cement applied externally to a wall. When applied internally, the coating is usually called 'plaster'. Smooth render is sometimes scribed to form a pattern of horizontal and vertical lines to imitate high quality ashlar stonework. 'Roughcast' render is formed using a coarse mix that is thrown - or cast - onto the wall.

Ribbon pointing

Pointing in which the mortar stands proud of the face of a wall (see Pointing).

Ridge

The horizontal narrow line formed by the juncture of two sloping surfaces on a roof, etc.

Roof grouting

To repair failing roofs a coat of lime mortar was applied to the exterior of a nailed or pegged slate roof to prevent the slates from lifting, and to keep out wind-blown rain and snow.

Roof trusses

Triangular-shaped frames of stout timber or metal that support the rest of the roof structure.

Roofing felt

A relatively modern material designed to allow any water that penetrates the outer cladding to drain safely into the rainwater disposal system.

Rooflight

A window built into a roof that lies flush with the roof surface.

Sash window

A wooden window whose panels open by sliding vertically using a system of cords and pulleys. In a Yorkshire sash or horizontal sliding sash window, the sashes open by sliding sideways in grooves in the frame.

Scarf joints

Where the ends of each roof timber are tapered and pinned together by oak pegs.

Septic tank

A large underground tank in which waste matter is decomposed by bacteria.

Soffit

The exposed lower surface of an element, such as arch, vault or balcony. Commonly used to describe the area beneath the overhang of a roof.

Spalling

Flaking of brick, stone or terracotta.

Sprigs

Nails used in glazing.

Stiles

The vertical part of a sash window frame.

Tanking

Adding a waterproof membrane to the inside of a wall.

Thermal bridge

A junction between two surfaces where heat is lost.

Tingle

A one inch (25mm) wide strip of copper, lead or galvanized steel, used to fix roof slates.

Torching

Slated or tiled roofs on older buildings are often ‘torched’. This is where lime mortar is applied between the battens to the underside of the roof. Its purpose is to prevent the cladding from lifting and to prevent wind-blown rain and snow from entering the building.

Maintenance Matters! Historic buildings

Glossary

Maintenance Matters!
Historic buildings