Maintain Your Church.

The Church Buildings Maintenance in Scotland project is designed to provide learning modules, toolkit modules and resources that will enable you to increase your knowledge of how to maintain your church…

The Maintenance Articles contain articles for study. The Toolkits provide answers to problems generally experienced in maintaining a church and information about the architectural features found in Scottish churches. The Resources provide additional guidance in the downloadable materials, as well as the opportunity to participate in discussion with other people involved in maintaining churches. You could also jumpstart your search by looking at our FAQs or Top Tips.

We hope this project will prove useful to you, and we welcome your feedback…

Maintenance Articles

Here you will find topical articles to allow you to better understand your church building and relevant issues of maintenance.

Glossary of Terms.

Click on a tab to read about terms starting with that letter.


A form of building in which the principal rafters extend down to ground level, and rest on concrete pads. The ends of the building are triangular. Related Words : Rafter



Used in two senses:1. Point at which a roof meets a wallhead.2. massive structure supporting the ends of a bridge

Related Words : Spandrel



Crushed stone, gravel, sand, or other granular material used in making concrete, mortar and plaster.  Coarse aggregate can be used to face pre-cast concrete panels, the product being known as ‘exposed aggregate’ panels. In some styles of pointing the surface of the mortar is brushed off to reveal the grains of aggregate on the surface.

Related Words : Wet dash, Concrete



Used in three senses: 1: a section of a church to one side of a main section, generally with a lower roof, and separated from it by a set of columns supporting the wall of the main section 2: a passage between sets of pews or chairs leading from the rear of the church to the chancel area 3: in Scottish churches, a subsidiary wing used for a specific purpose, for instance as a burial vault, or for the celebration of Communion

Related Words : Wing, Arcade, Clerestorey



This light, silvery, metal is relatively resistant to corrosion, except in salty environments. It is sometimes used to make gutters and downpipes. In sheet form it is occasionally used for ridging, but its lightness makes it vulnerable to high winds.

Related Words : Gutter , Ridge, ridging, Hopper head


Apse, apsidal

A projection from the east end of a church, originally to house an altar, but more recently, in the Presbyterian churches, to house a Communion table. An apse-like (apsidal) extension is frequently used to house a pipe organ. Apses are usually rounded, or semi-octagonal.

Related Words : Organ chamber



An arcade is a row of linked arches. Inside a church arcades usually separate aisles from the nave or choir. Blind arcades are sometimes used as decorative features on the exteriors of churches.


An arch is a curved structure spanning an opening. In a round arch the structure is semi-circular, and in a pointed arch the sides are less tightly curved, and meet at the top of the arch in a point. These are the most commonly-encountered forms of arch in church buildings. In a masonry or brick arch the stones forming it are usually wedge-shaped, and are known as voussoirs. In a round arch the voussoir at the top is known as the keystone. Wedge-shaped stones or bricks can also be used to form a flat arch, which sometimes takes the place of a lintol, at the head of a window or door opening.

Related Words : Haunching, Romanesque, Keystone, Machicolation, Spandrel, Tympanum



A building professional with a degree or equivalent qualification in the design of buildings. A recognised architect will also be a member of a professional body, such as the Royal Incorporation of Architects in Scotland. Major works of repair should be undertaken as specified by, and under the supervision of an architect with experience of conservation. An architect in practice will be covered by professional indemnity insurance, and clients should assure themselves that such insurance is in place.

Related Words : Quinquennial inspection, Structural engineer



In Classical architecture, the pieces of stone which link the capitals of columns in a portico or colonnade. Part of the entablature.

Related Words : Capital, cap



The sharp edge of a building component, such as a window or door surround.

Related Words : Chamfer



Masonry consisting of large blocks, with rectangular outer faces, laid in regular courses, and brought to a regular face, with fine mortar joints. Smooth ashlar is termed ‘polished’. Other surface treatments are described as ‘stugged’ and ‘droved’.

Related Words : Chip carving, Droved, Mortar, Rubble, ruble



Traditionally a material made by mixing natural pitch with fine aggregate, and used for surfacing and waterproofing. In buildings, sometimes used to cover flat or low-pitched roofs. It is a durable finish, if properly cared for, but can crack, allowing water to penetrate it. Modern asphalt is usually made from the residues of petroleum refining.


Part of a window frame. Specifically a strip, usually of wood or metal, separating two panes of glass.

Balustrade, baluster

A form of protection to the edge of a building or terrace, consisting of vertical masonry (or cast-iron or concrete) uprights with massive bases and copes. The uprights are ‘balusters’, and are usually shaped in an ornamental way. Balustrades are often divided into sections by ‘dies’, solid sections rising above the copes.  


In a roof which overhangs the masonry of a gable, the boards on the outer edge of the roof, protecting the exposed ends of the purlins.  


A name given to the lower part of a wall, where it projects from the face of the upper part. The basecourse serves to thicken the wall where it meets the foundation, and also to shed water away from the base.


A thin strip of wood. Mounted vertically, battens serve to support the laths in a lath and plaster wall, and mounted horizontally, to support the tiles (and sometimes slates) on pitched roofs.

Related Words : Rafter, Rosemary tiles, Tiles, Lath and plaster



In a sash-and-case window, the strips of wood which separate the sashes, allowing them to slide past each other. Also used to describe a rounded moulding.


This word describes the placing of blocks of building materials on a layer of softer material (mortar or sand). Stones such as sandstones, slates, and flagstones were formed by depositing silt, or drifted sand, in layers. When building in sandstone these layers should be horizontal, or nearly so. If, in a stone built into a wall, the layers are vertical, it is described as ‘Face bedded’, and is more vulnerable to decay than if the layers were horizontal.

Belfry stage

In a tower, spire or steeple, the section in which a bell or bells are hung. Provided with openings, usually louvred, to allow the bell(s) to be heard.

Related Words : Louvres, Louvre



A term used to describe a roof in which the slope flattens out just above the wallhead.

Bellcote, belfry

Also belfry, a support for a bell or bells, usually mounted on a gable or wallhead. In churches with towers, spires or steeples the bell or bells are usually in a chamber at the top of the tower.

Related Words : Cupola



A chemical preparation used to kill plants, fungi or animals which are damaging a building, or to control vegetation growth.

Bitumen, bituminous

A thick, tarry material, the residue of coal-tar or petroleum refining. In building it is used in making roofing felt, in coating materials such as brick, breeze block, or masonry to waterproof it, and, in bituminous paint, as a waterproofing material for local application

Related Words : Damp-proof course (DPC), Felt (roofing)


Blind (of arcades etc)

A term used to describe an arch, or arcade, or other feature which has solid infilling.

Related Words : Foil, Oculus



When a church was being built of stone, some of the stones intended to be carved were frequently built in as roughly-shaped blocks. If the carving was not undertaken, the masonry is said to be ‘in block’.

Blocking course

In classical buildings, the masonry above a cornice, whose mass gives stability to the latter.


Walls or other features built of pre-cast concrete or breeze blocks

Related Words : Cavity wall, Render


Boss, bossed

When a rendered finish, such as harling separates from the underlying masonry or brickwork it is said to be boss, or bossed. If the affected section is tapped it responds by returning a dull sound.

Box gutter

A gutter of rectangular cross-section, usually on top of a wallhead. The gutter may be made of stone, wood or metal. Such gutters are sometimes referred to as ‘secret’ or ‘parapet’ gutters.

Related Words : Lead


Breeze block

A building block made of some light aggregate bound with cement. Breeze blocks were originally made with ‘breeze’ – small pieces of gas-works coke. They are now made with foamed slag, a by-product from iron-smelting. Usually used to make internal walls


Five types of brick are likely to be found in church walls.1. Blaes bricks. These are made from powdered coal measures clays, lightly fired. They usually have black patches on one or more faces. When used for external walls they should be rendered.2. Clay bricks. These are generally red all over, and are heavier than blaes bricks. They do not need to be rendered, but sometimes are.3. Facing bricks. These are usually plastic-clay bricks, but have a surface designed to be seen. Smooth-faced ones are sometimes terra-cotta ones. Rough-faced ones are termed ‘rustic’ bricks.4. Engineering bricks. These are fired at a high temperature, and are very heavy and strong. They are often bluish in colour, or a dark red. As they are dense they can make an effective damp-proof course;5. Lime-sand bricks. These are made by curing, at a low temperature a mixture of slaked lime and sand, or crushed spent shale. They are usually a light purple or pink in colour.

Related Words : Fireclay, Cavity wall, Mastic, Open joints, Pointing , Render, Lath and plaster



A building-trade craftsman who specialises in laying bricks, a skill by no means as easy as it looks.

Bronze grille

As the name suggests, a mesh of bronze wire, used to protect stained or leaded glass windows. If properly designed and made they are almost invisible in normal lighting.

Building surveyor

A building professional with training and experience in ascertaining the condition of a building, and recommending remedial action. Some building surveyors are specially qualified to examine historic buildings. Building surveyors can also estimate the value  of buildings.

Related Words : Quinquennial inspection



Of masonry, made of blocks with curved outer faces. Also used to refer to the timber with lead capping at the edge of a flat roof

Related Words : Rock-faced



A rib of masonry projecting from the face of a wall. Its primary purpose is to strengthen the wall, and to resist the outward thrust of roof trusses or masonry vaulting, but it also has a decorative purpose.

Related Words : Pinnacle



The grooved strips of lead which form the structure of a stained or leaded glass window

Related Words : Leaded glass, Polycarbonate sheet, Quarries, Saddle bar, Stained glass


Cap house

A structure covering the top of a spiral staircase giving access to the top of a tower or wallhead

Capital, cap

The top section of a column, in classical architecture. immediately under the architrave. In Romanesque and Gothic architecture the capital (often abbreviated to ‘cap’) is usually the point from which the arch begins to curve (‘springs’).  


A covering, usually of lead, applied to the top of a wall or other feature, to prevent water penetration.

Casement window

A window set in a frame which is hinged at one side, and opens sideways, or from the top or bottom as a hopper.

Cast iron work

Cast iron objects are made by melting iron and pouring it into moulds. The material is often used to make gutters, hoppers and downpipes. Sometimes it is used to make window frames, and internal supports, such as columns and beams. It is also used to make ornamental items, such as gates, railings, roof ridges, finials and weather-vanes. It can generally be distinguished from wrought-iron by being less delicately proportioned.

Related Words : Finial, Gully, Gutter , Ogee gutter, Ridge, ridging, Balustrade, baluster,Hopper head


Cathedral glass

Leaded glass made with small regularly-shaped rectangular or diamond-shaped panes. The panes are usually translucent, and of a variety of pale colours

Cavity wall

Wall, usually of brick or blockwork, built with an inner and outer skin, having a space between the skins, known as the cavity. The two faces are linked by wall-ties. In modern construction the cavity may be fully or partly filled with insulation

Related Words : Wall ties


Cement, cementitious

The term cement usually refers to Portland Cement, a substance made by roasting limestone and clay, and grinding the resulting mass into a powder. When mixed with water it sets to form a hard mass. When mixed with sand it can be used as a mortar, and with aggregate it forms concrete, or can be spread over a wall-face as a render. Cement mortars and renders are suitable for brickwork, but can damage masonry, especially if made of soft stone.

Related Words : Portland cement, Concrete, Dry dash, Harl, Harling, Mortar, Render,Parging



The cutting off of the sharp edge of an arris at an angle, usually of 45 degrees. Serves to prevent damage to the edge, and in windows to increase the amount of light transmitted through them.

Related Words : Quoins, Rustication



The part of a church in which the altar or communion table is set. It should, in a Church of Scotland, also accommodate the font, and usually the pulpit. It is sometimes a separate chamber at the east end of the building, but is commonly simply an area at the east end of a rectangular worship space.

Related Words : Choir, Nave


Chip carving

A way of decorating masonry by cutting holes and grooves into ashlar, to form geometric patterns.


This term has two meanings. 1. A body of singers, used to lead worship and 2. A separate chamber at the east end of a church, housing the altar or Communion table, and sometimes seats for a choir (1). The choir (2) is usually narrower and lower than the main body (nave) of the church, and may be referred to as the chancel.

Related Words : Clerestorey


Cill (sill)

The bottom member of a window opening. It is usually made of stone or concrete, often with a timber cill on top. It generally projects beyond the face of the surrounding wall, and sheds water away from it.


Used of architecture inspired by Greek or Roman design, with the use of columns or pilasters. Classical churches are usually symmetrical. There are three basic detailed designs of columns, and of the other principal features of classical buildings, referred to as orders. These are the Doric, Ionic and Corinthian orders.

Related Words : Architrave, Georgian, Capital, cap, Column, Entablature, Fluting, Frieze,Low relief , Modillion, Pilaster, Portico, Rustication , Steeple



The row of windows in a nave or choir, set above the aisle roof. Also used to refer to any high-level windows above a roof

Coarse stuff

A mixture of slaked lime and coarse sand, allowed to mature for several weeks, and then used as a constituent of lime mortar


A row of columns, other than those forming a portico


One of the structural elements of a classical building, a tall, circular-section object supporting the upper part of the building.

Related Words : Classical, Architrave, Aisle, Capital, cap, Colonnade, Engaged columns,Entablature, Fluting, Pilaster, Portico



A mixture of Portland cement, sand, gravel and water. Lime may be used in place of the cement, in which case the mixture is known as lime concrete. If rods of steel are embedded in the concrete it is reinforced concrete. It these are put under tension while the concrete is setting, it is pre-stressed concrete. Reinforced concrete made in a mould to be used off-site is pre-cast concrete. Non-reinforced concrete is known as mass concrete. The timber or metal moulds used in casting concrete on site are known as shuttering.

Related Words : Aggregate, Cement, cementitious, Damp-proof course (DPC), Reinforced concrete, Tiles, Balustrade, baluster


Copes, coping

In building terms, a cope is the covering for an exposed wallhead. Copes generally overhang the wall they cap, to shed water. Some are roughly triangular in cross-section, others almost flat. They are usually made of stone or concrete

Related Words : Gablet, Balustrade, baluster



Copper in sheet form can be used as a durable roof covering, and occasionally as a wall-cladding. Brownish when installed, it turns green. Copper is also the preferred material for lightning conductors.

Related Words : Duckboard, Lightning conductor, Saddle bar


Corbel, corbel table, corbelling

A corbel is a stone which projects from a wall-face, to support a floor or roof, or some other structure. A row of corbels, with spaces in between, at a wallhead, is known as a corbel table. A continuous row of such projecting stones is known as corbelling.

Related Words : Eaves, eaves band, Machicolation


Corrugated iron

Sheet-iron or steel coated with zinc (galvanised), and rolled into a continuous wave form. This stiffens the sheet in one dimension. Corrugated iron was formerly extensively used for the walls and roofs of temporary buildings (see tabernacles). Sheets curved in the direction of the corrugations are remarkably strong, and were used in building Nissen huts, as in the Italian Chapel in Orkney. Sheet steel with sharp-edged corrugations is termed ‘profiled’ steel.

Related Words : Steel, Zinc


Course, coursed

A course is a row of adjacent stones or bricks, of the same height. Coursed stonework has a series of such rows, with the vertical joints staggered

Related Words : Damp-proof course (DPC), Rubble, ruble



The treatment of a parapet wallhead as in a mediaeval castle, with tall and short sections alternating. Common in early Gothic Revival churches.


The name given to ornamental cast-iron roof ridging.


Stylised leaves carved along the edges of pinnacles, or round doorways, in late Gothic and Gothic Revival buildings

Related Words : Poppy head



In a cruciform church, the area where the four arms of the cross meet. In many cruciform churches there is a tower over the crossing

Crown steeple

A form of steeple in which the masonry of the corners of a tower is carried up in a curve to meet above the centre of the tower.

Related Words : Steeple



The fashioning of the skews of a gable as a series of steps, a traditional Scots vernacular feature


Used to describe a building on a cross plan. Most cruciform churches are on a Latin cross plan, in which one arm of the cross is significantly longer than the other three. A cross with equal arms is known as a Greek cross.

Related Words : Crossing, Transept



A domed top stage of a tower, often used as a belfry. Also used to refer to a large glazed rooflight over a hall or stairway.

Dado rail, panelling

A waist-height projecting rail, running along an inside wall. Commonly the area below the dado rail is covered with vertical boarding. Sometimes it is panelled. Wooden panelling is also commonly used round a chancel area (see wainscotting)..

Damp-proof course (DPC)

Used in two senses. A damp-proof course installed during construction is usually a layer of slate, concrete, or bitumen low down on a wall, to prevent ground water rising above that level. The damp-proof course should be about six inches (125mm) above ground level, as over time the earth round a building can build up, ‘bridging’ over the course and allowing moisture to reach the interior of the building. In the other sense, an impervious layer of plastic or lead can be inserted at a wallhead, or below a cope, to stop water penetrating from above. Related Words : DPC 


A traditional water-based paint, the application of which allows a wall to ‘breathe’ (to absorb and emit water). It is an unsuitable base for applying modern paints.

Down pipe

Also known as a conductor, a pipe linking a gutter to a drain at the base of a wall. Related Words : Cast iron work, Gargoyle, Gully, Handhole, Internal downpipe, Joint, Lead, Rainwater goods, Rhone, Swan neck, Drainpipe shoe, Hopper head (4 Photos) DPC see Damp-proof course

Drainpipe shoe

The curved, open-ended lower end of a downpipe, directing water away from the base of a wall. Also seen where water from an upper roof is discharged on to an aisle roof. Related Words : Rainwater goods 


A name given to the dressed (finely-finished) stones forming the edges of walls and window and door openings in a masonry building. Often emphasised by being made of different stone to the wall body, and sometimes by harling over the wall, except for the dressings. 

Drip mould

A projecting strip of stone above a window or door, usually curved on its upper face, and grooved on its lower one, to shed water away from the opening. Related Words : Label stop 


A treatment of ashlar masonry in which a series of parallel grooves is cut along the face of individual stones. These are frequently at an angle, and may be very slight, or quite prominent. 

Dry dash

A treatment used to finish the walls of modern buildings, in which a layer of cement render is applied to the surface. While it is still wet, crushed marble or white limestone is thrown (dashed) on to it, so that the chips are partly embedded in the render. It is not a suitable treatment for an historic building. Related Words : Wet dash, Render 


Where a roof has lead or copper gutters or platforms, slatted wooden walkways – duckboards – should be fitted, to prevent damage to the metal covering during routine maintenance and inspection. Duckboards also allow water to drain away after heavy snow.


Here used to describe a channel within the thickness of a wall or other structural component, used to accommodate pipes or cables, or for ventilation or heating. Related Words : Internal downpipe

East end (liturgical) (and north, south and west)

Many pre-Reformation churches were built with their long axis running east-west, so that the altar was nearest to Jerusalem. The geographical orientation of more recent churches is random.. It is unwise to use the liturgical term in dealing with contractors. The geographical north, south, etc (as on a map) should be used instead. Related Words : Apse, apsidal, Chancel, Choir, Narthex 

Eaves, eaves band

The eaves of a building with a pitched roof are the edges of the roof, where it meets the wallheads. If the roof overhangs the wallheads, the eaves are said to be ‘open’. If the top course of the wall projects beyond the surface of the rest of the wall it is said to be an ‘eaves (or wallhead) band’. This feature can also be described as ‘corbelled eaves’. Related Words : Outriggers 

Engaged columns

Half-columns applied to the face of a building. 


In classical architecture, the mass of masonry above a row of columns, or above a door or window opening and below a pediment (if any). Related Words : Portico 

Etched glass

Glass to which a pattern has been applied by roughening or removing part of the surface. Properly speaking, etching is done by dissolving the surface using chemicals, but glass may also be ‘etched’ by sand-blasting.

External stair

A stairway to the upper level of a building (usually a gallery or loft), and usually open to the elements.


A band of timber or plastic boarding fitted below a wallhead on a building with a flat or low-pitched roof. It is sometimes decorative, but often functions as a weather baffle, or supports gutter fixings. Related Words : uPVC 

Felt (roofing)

A layer of fibrous material, impregnated with bitumen, and coated with a layer of bitumen, often with fine gravel applied to it. Used for covering flat and low-pitched roofs. Multiple layers can be used in exposed conditions, or to give longer life It is a good material if its limited life is accepted, and if is kept in good repair. Because it is impervious, it is important that the under-surface of the supporting material (usually plywood) is well ventilated. Related Words : Flashing 


A material made by impregnating a mat of spun glass (glass fibre) with some kind of resin. It has been used as a material for gutters, and as a lightweight substitute for metal structures. It is prone to attack by the ultraviolet rays in sunlight. Lexan is a translucent fibreglass sheet sometimes used to protect windows suffering from considerable vandalism.


A band of mortar, usually applied to the junction between a roof-covering and a skew. Also known as a ‘parged fillet’.


A vertical feature used as a decorative finish to a spire or steeple, at the apex of a gable, or the end of the ridge of a piended roof. Finials may be made of stone, terra-cotta, wrought or cast-iron, and vary enormously in size and complexity. Related Words : Cast iron work 


A type of clay found in association with coal and shale which when fired is particularly resistant to heat. Fireclay was formerly used to make facing bricks, ornamental features, ridging and below-ground drainage pipes and gullies. Fireclay bricks are yellowish, or whiteish. Salt-glazed fireclay pipes and other products are shiny and brown. Related Words : Gully, Ridge, ridging


A layer of sheet lead or zinc, or of roofing-felt, covering the joints or edges of a section of roof covering and a wall. 


A small spire on a roof-ridge, usually with a wooden or metal frame. If of wood, covered with lead. Sometimes used to cover a ventilator. 


The cutting of grooves, of semi-circular cross-section, in masonry, especially when this is applied to the shafts of columns in classical architecture. 


One of the lobes in a Gothic window or blind opening, as in trefoil (three lobes), quatrefoil (four lobes), or cinquefoil (five lobes). 

French drain

A trench filled with broken stone, cut round the walls of a building to prevent ground water affecting the walls. Also used of a perforated pipe in a similar setting, or behind a retaining wall.


In a classical building, a band of masonry above a portico, or a window or door opening, situated above the lintol(s). 


A chemical preparation made to kill fungus infections, such as dry and wet rot.

Gable, gabled

A gable is a wall with a triangular head, built to support a pitched roof. The roof may rest on the inner side of the skews of the gable, may cover them, or may overhang them. A building with gables may be referred to as ‘gabled’. Related Words : Rafter, Bargeboards, Finial, Gablet, Hip (hipped) roof , Poppy head, Skew, skewput, Urn 


Used in two senses: 1. a small triangular projection from a wallhead, acting as a gable for a sub-roof.2. a cope of a triangular section, designed to shed water from a wallhead or parapet. 

Galvanised mesh

A panel of steel wire in the form of a grille. The wire may be woven, or in straight lines welded where the wires cross each other – ‘weldmesh’. The term ‘galvanised’ means that the wire has been coated with a thin layer of zinc. This coating prevents the rusting of the underlying steel. Galvanised mesh is used to protect windows from vandalism. Related Words : Zinc 


A projection from a wallhead, originally designed to take rainwater away from the face of the wall. In many 19th century buildings gargoyles are fitted with no practical function, as rainwater is disposed of through downpipes. 


Georgian architecture, built in the 18th and early 19th centuries, is generally-speaking, characterised by simplicity, with plain wall surfaces, large window openings, and careful attention to proportion, and to the relationship between architectural features. In more elaborate Georgian buildings, classical features are often employed. Roof pitches are usually, low, and roofs concealed behind parapets or upstands. In Scotland, classically-detailed steeples, and large round-arched windows are distinctive features of many Georgian churches. Related Words : Keystone, Quoins

Georgian wired glass

Panels of glass made with steel wire mesh embedded in the thickness of the panel. The glass is usually made with a rough surface. Used in situations where the shattering of a pane would be risky, either for safety or for security, for instance in rooflights.

Gibbs surround

The ornamentation of a door or window opening by having the margins composed of boldly-projecting quoins alternating with more slightly treated and moulded quoins. A treatment devised by James Gibbs, an Aberdeen-born architect who flourished in the first half of the 18th century. 


A trade name for a beam made from small sections of wood glued together. Laminated timber beams are very strong, and are used to support the roof in many modern churches.

Gothic (revival)

The Gothic style of architecture was developed in the late 12th century AD, and is characterised by the use of pointed windows. It continued to develop until the 16th century. A few Gothic churches were built in the 17th and early 18th centuries. The style was revived – ‘Gothic Revival’ – in the early 19th century, and continued in use until the 1950s. Related Words : Gothick, Crenellation, Crockets, Foil, Niche


A term used to describe buildings designed in the late 18th and early 19th centuries with a limited understanding of the details of ‘real’ mediaeval Gothic architecture.

Graded slates

Used of roofs where the size of the slates decreases from the bottom to the top of the skews. Gives the roof a graceful finish. Often described as slates laid in ‘diminishing courses’. 


A dark-coloured rock common in the Southern Uplands, and used extensively in church buildings there. It cannot be dressed to a fine finish.

Ground water

The water in the ground round a building. This can simply originate in local rainfall, or can well up from adjacent, higher areas of ground. If not adequately controlled, ground water can damage a building, either by supporting wet or dry rot, or by washing away light soil under foundations.


An open-topped box, made of glazed fireclay, cast iron, or plastic, at the base of a wall, into which a downpipe discharges. The top of the gully should be covered by a perforated plate, which can be removed to allow debris to be cleared. A pipe from the side of the gully should link to a drain carrying the water away from the building. Related Words : Rainwater goods 


The channel that catches rainwater at the edge of a roof. It can be made of cast-iron, plastic, aluminium, lead-lined timber, or stone. Also known as a rhone. Related Words : Sacrificial flashing, Cast iron work, Down pipe, Duckboard, Fibreglass, Joint, Ogee gutter, Parapet, Rainwater goods, Rhone


A term used to describe a building in which a timber frame has the spaces between the timbers filled in with brickwork or other material. In buildings constructed in the late 19th and early 20th centuries the visual effect of half-timbering was sometimes achieved by applying non-structural thin timbers to the face of a load-bearing wall. 


An opening at the bottom of a downpipe, with a cover-plate. If the pipe chokes the plate can be taken off to allow the pipe to be cleared with rods. Sometimes referred to as a rodding plate. 

Harl pointing

A form of pointing in which the mortar is spread over the surface of the masonry, leaving the central part of the stones exposed. Sometimes colloquially referred to as ‘bag rubbed’. 

Harl, Harling

A form of render in which a mixture of cement or slaked lime and coarse sand or fine gravel is applied to (traditionally hurled at) a masonry or brick wall. For the best effect the mixture should be dashed against the wall. The hard finish obtained by the use of cement can be damaging to the underlying masonry or brickwork. Related Words : Dressings, Margin, Render 


The lower part of an arch. Also refers to a sloping built-up shoulder of mortar to help to shed water from a right-angled junction, for instance between a chimney stack and a chimney can.

Header tank

A small cold-water tank for topping up, for instance, a central-heating system. Sometimes called an expansion tank.

High relief

Sculpture in which the front face of the figure or other image is formed in three dimensions, but the back remains attached to the stone or other background material 

Hip (hipped) roof

A roof in which the wallheads are all level, that is, there are no gables. Related Words : Rafter, Piended roof

Hopper (window)

A part of a window, hinged along its base, which can open inwards. Related Words : Casement window, Cast iron work 

Hopper head

A box to catch rainwater, mounted at the top of a downpipe. It can be made of cast-iron, lead, aluminium or plastic. Related Words : Lead, Rainwater goods 

Hydraulic lime

Lime made by burning limestone containing some clay, and therefore a natural cement. If mixed with water it will set quickly, even under water. There are different grades of hydraulic lime, which can be used to make mortars or renders of different degrees of hardness and water-resistance. Related Words : Lime mortar, render, limewashing

Indent, indenting

Indenting is the technique of cutting out a decayed stone (or brick) and replacing it with a new one. The replacement stone (or brick) should be similar chemically and in colour to the surrounding material, otherwise indenting can hasten the decay of adjacent stones or bricks. 

Induction loop

A wire loop carried round a space to relay signals to hearing aids


The inner faces of a window or door opening. Related Words : Jamb, Mastic

Internal downpipe

A downpipe inside a building, or in the thickness of a wall, usually hidden in a duct. Related Words : Rainwater goods


A general name for door and window fittings, including hinges, locks and catches, handles and knobs. Related Words : Wrought iron


Used in two senses:1. The side of a door or window opening (also ingo). 2. A wing projecting from the body of a building. 


The space between stones or bricks in a wall, usually filled with mortar. The term is also applied to the points at which sections of gutter, downpipe, etc meet, and to a narrow channel, filled with a flexible material) in brickwork or render to allow for expansion and contraction (an expansion joint). Related Words : Slaister


1. A horizontal beam, generally one of the beams used to support flooring or a ceiling. 2. A rolled steel beam of I section, known as a rolled steel joist (RSJ). Related Words : Lath and plaster


The topmost of the stones forming a round-headed arch, sometimes made to project from the plane of the arch. In Georgian architecture an ornamental keystone is often applied to the centre of a lintol.

Label stop

The name given to the lower end of a drip mould. Usually a short horizontal section of the same form as the drip mould, but sometimes a carving of a human head, a grotesque animal, or a bunch of leaves. 

Laminated beam

A timber beam made up of relatively thin strips of wood, glued together. Much used in modern church building. 


A tall, narrow, generally pointed window. The term is also applied to round-headed windows of similar proportions. 

Lath and plaster

A way of finishing interior walls and ceilings, in which vertical wooden battens are fixed to a masonry or brick wall, or to ceiling joists. Closely-spaced parallel strips of wood – laths – are then nailed to the battens, and plaster applied to them. The plaster oozes out at the back of the laths, forming a key, so that when dry it does not fall away from them. Related Words : Batten, Plaster


A softish, heavy metal, with many applications in building. Used for covering flat or low-pitched roofs, for flashing, lining box gutters, and sometimes for rainwater hoppers and downpipes. It can also be used for ridging. If properly designed, it is an excellent material for most roofing work. Related Words : Plastique, Sacrificial flashing, Terne coated steel, Cames, Capping, Damp-proof course (DPC), Duckboard, Gutter , Parapet, Platform roof, Ridge, ridging, Stained glass, Water gate, Flashing, Hopper head Click thumbnail to view image

Leaded glass

A term used to describe glazed openings filled with glass panes set in a framework of lead cames, but where the panes do not have designs painted on them. Related Words : Weldmesh, Cames, Polycarbonate sheet, Saddle bar, Stained glass 

Light (window)

A term used in describing the major subdivisions in a traceried window, thus a two, three-light window, etc. 

Lightning conductor

A band, usually of copper, running from the top of a tower, spire or steeple to the earth at its base. In the event of a lightning strike the electric charge is conducted harmlessly to earth, avoiding damage to the building. Related Words : Copper 

Lime, mortar, render, limewashing

Lime is a term used to cover two compounds of the metal calcium. Quicklime is made by heating limestone or chalk, to drive off carbon dioxide. When water is added to quicklime heat is given off and it becomes slaked lime. If slaked lime is mixed with sharp sand in the right proportions it can be used to make the joints between stones or bricks, mortar, or applied to a wall surface as a render. Pure lime mortars and renders take some time to harden properly, and the use of hydraulic lime is sometimes necessary to achieve a durable result. Lime mortars and renders have to be accurately specified, mixed and applied in the right conditions, but they are better for the health of buildings than their cement-based alternatives. Lime can also be used, in a mixed solution and suspension, as a coating for masonry or render, known as lime wash. Related Words : Limestone, Putty, Slaister, Coarse stuff, Harl, Harling, Hydraulic lime, Mortar, Plastic repairs, Render 


Stone formed from the skeletons of marine animals. Limestone does not occur sufficiently widely in Scotland to be used as a building stone, but was commonly ‘burned’ to make quicklime for lime mortar, render, etc.


A commercial product which has been used to coat superficially-decayed or discoloured masonry to improve its appearance. It is impervious to moisture, but if the stone behind becomes damp it can quickly rot away. 

Lintol, lintel

The top member of a rectangular window, door, or other opening. Lintol is the traditional Scots building term. Related Words : Frieze, Keystone, Arch 


Used in two senses:1. An attic.2. A gallery, especially one occupying an arm of a long rectangular or T-plan church. The gallery facing the pulpit in a T-plan church was often reserved for the principal landowner, or heritor, responsible for the building and for paying the stipend of the minister. It was in these circumstances known as the ‘Laird’s loft’. 

Louvres, Louvre

Slanting boards fitted into an opening, allowing air and sound to pass through, but preventing the passage of rainwater. Commonly fitted to the belfry stages of towers and steeples. Related Words : Belfry stage 

Low relief

Used of sculpture, meaning flattened rather than fully realised. The French – ‘Bas relief’ – is also used. Related Words : Pilaster 


A canopied opening in a spire. (2 Photos) Lych gate A covered gateway at the entrance to a churchyard.


A corbelled wall-head with the corbels linked by small arches. In ‘real’ machicolation there were spaces at the heads of the arches for dropping offensive materials on people attacking the wall. Later the treatment became purely decorative. 


A raised band round a window or door, or at the edge of a wall. Sometimes an indication that a building was designed to be harled. Related Words : Gibbs surround 


A building trades craftsman who can work stone for inclusion in a building. For work on historic buildings a mason with experience in that field is essential.


Building fabric made of stone. Sometimes the term masonry is used in reference to brickwork, but this is an undesirable expansion of the meaning of the word. Related Words : Slaister, Ashlar, Bargeboards, Chip carving, Wallhead, Entablature, Fluting, Frieze, Harl, Harling, Harl pointing, Mastic, Open joints, Pointing , Render, Rubble, ruble , Vegetation, Balustrade, baluster, Lath and plaster


A mixture of linseed oil with burnt sand, used to seal a wooden window or door frame to the ingoes of the masonry or brickwork opening. The flexibility of the material accommodates the different rates of expansion between timber and stone. 

Mechanical and electrical engineer

A professional with particular expertise in the design of environmental control and of electrical power supply. Often abbreviated to M & E engineer. Related Words : Services engineer


One of a series of projections under a cornice, especially in classical buildings. 


Used of a roof sloping in one direction only. Popular from the late 1950s to the 1970s, and again now. 


A material used to fill the gaps between stones, blocks or bricks in wall-building. It adheres to the components of the wall, creating a structural block. Traditional mortar was made with lime and sand, or clay was used as mortar. After the invention of Portland cement in the 1850s it was used as a substitute for lime, and is still used in that way. In finely-jointed ashlar a putty of lime in linseed oil is sometimes used. Generally speaking, mortar should be softer than the materials surrounding it, otherwise it may encourage decay. In historic buildings lime-based mortars are now preferred to cement-based ones. Related Words : Slaister, Aggregate, Ashlar, Cement, cementitious, Fillet, Harl pointing, Hydraulic lime, Joint, Lime mortar, render, limewashing, Open joints, Pointing 


A linear ornamental feature of a building, of the same cross-section along its length.


In a masonry-framed window, a horizontal stone glazing bar. Also used for vertical stones.

Nail sickness

A condition of roof in which the nails fastening the slates to the sarking have rusted away to the extent that the slates begin to slip over a significant area. 


A covered space between the ‘west door’ of a church (see east) and the nave, separated from the latter by a wall. Often called a ‘vestibule’ in Scottish churches. 


In pre-Reformation churches, the part of the worship space used by lay people. Often used for the body of a church outside the chancel area. Related Words : Choir, Clerestorey, Narthex, Transept 


A recess in the face of a wall, or a recessed opening in, for instance, a gable-head, intended to house a figure sculpture. In some Gothic Revival buildings empty niches are used as decorative features.


A round opening, often glazed, as a window, but sometimes blind. 

Ogee gutter

A cast-iron gutter, one side of which has an ogee profile. The base and the other side, are flat, and the base sits on top of a wallhead. 

Ogee, ogival

A double curve, bending first one way, then the other, on either side of a vertical line. 

Open joints

A term used of masonry or brickwork where the mortar between stones or bricks has eroded. Open joints are a very common reason for water penetration. 

Organ chamber

A space, often built on to a chancel area, to accommodate a pipe organ, and often apsidal in form. Organ chambers can also be formed within the envelope of a conventional worship space.


A name given to the exposed ends of rafters and purlins, projecting beyond the wallheads in a building with oversailing eaves. Also referred to as ‘sprockets’. 

Oversailing eaves

A term used to describe the overhangs in a building in which the roof overhangs the walls. It may simply overhang at the sides, or at the sides and ends. Related Words : Outriggers


A low wall at the edge of a roof . There is often a lead gutter behind a parapet, and sometimes a walkway. Related Words : Georgian, Crenellation, Gablet 


A cement fillet at the edge of a roof where it abuts a skew. Related Words : Fillet 


A floor surface made up of short pieces of thin wood arranged in geometrical patterns.


Usually, a triangular feature above the columns in a portico, or above a window or doorway. Sometimes the top of a pediment is curved. Related Words : Entablature, Portico, Tympanum

Piended roof

A Scots term for a hipped roof. Related Words : Hip (hipped) roof 


A low-relief pillar applied as a decoration to the face of a building. Related Words : Classical, Low relief 


An upright support of square cross-section. 


A tall, pointed decorative feature, usually at a corner of a building, or above the top of a buttress. Related Words : Crockets, Poppy head 


Small stones inserted into a rubble masonry wall, between larger stones. If the large stones are irregular, these stones are necessary for the stability of the wall, but sometimes square pinnings are used ornamentally, with roughly-squared large blocks. When a wall is repointed, the pinnings should be retained in place, or put back if it is necessary to remove them temporarily. Related Words : Rubble, ruble 

Pitched roof

A roof formed with one or more sloping surfaces. Each of these surfaces is a pitch, or skew. Related Words : Eaves, eaves band, Saddleback tower, Skew, skewput 


A material applied to a wall-face while plastic, hardening on exposure to air. Internal plaster is generally made from gypsum (calcium sulphate) mixed with sand, but traditionally lime-based plasters were used. Ornamental plasterwork is made with hair or other fibrous material, to give it added strength. The interior walls of churches are usually either finished with lath and plaster, or with plaster applied directly to the masonry or brickwork – plastered ‘on the hard’. In modern building plasterboard, a layer of plaster sandwiched between layers of protective material, is often used as a wall-finishing material. Related Words : Vault, Aggregate, Lath and plaster

Plastic repairs

A term used to describe the replacement of eroded stones by a mortar-like mixture, soft when applied, hardening on exposure. Lime-based repairs of this character can be effective and durable. 


A form of plastic material used to form valley gutters, sections of raised roof and other features traditionally made of lead, or sometimes of copper. Less durable than the metallic counterparts.

Platform roof

A roof with sloping sides and a central flat section, usually covered in lead. 


A raised platform supporting the upper part of a building, or providing the base for a sculpture. 


The application of mortar to joints in masonry or brickwork. Good pointing has to be undertaken using appropriate mortar, and a surface treatment appropriate to the type of stone or brick of which the wall is made. It should also take account of the direction in which the wall faces, and the quantity of rain expected. Related Words : Aggregate, Harl pointing, Skew, skewput 

Polycarbonate sheet

Clear plastic sheet, sometimes used to protect stained or leaded-glass windows. Not an ideal solution, as it can accelerate the decay of the lead cames and painted decoration, unless properly ventilated. 

Polychrome, polychromy

A term used to describe a building constructed of stone or brick of more than one colour, especially when the colours are used to decorative effect.

Poppy head

In a crocketted feature (door or window opening, pinnacle or gable), the carved decoration at the top of the feature. 


In classical architecture, a projection from the body of a building consisting of a row of columns supporting an entablature and often a pediment. Related Words : Colonnade, Frieze 

Portland cement

See cement. Related Words : Cement, cementitious


Glazier’s putty is a mixture of whiting (crushed chalk) with linseed oil, used to fix glass panes into a window frame. Lime putty is the product of slaking quicklime, after storing it under water for some time.

Quantity surveyor

A building professional who can take an architect’s drawings and specification, determine the quantities of materials needed to complete a building, and assess the cost of the materials and work needed to finish the building.


In describing windows, quarries are small rectangular or diamond-shaped panes of obscure glass, set in cames to form a whole window, or part of a window. 

Quinquennial inspection

An inspection of a building made by an architect or building surveyor, every five years, to specify repairs needed, and to recommend the degree of urgency of particular work.


The stones at the corners of a building. In Georgian buildings they are often emphasised by making them project from the wall face, and chamfering all their exposed edges, except the corner itself. This treatment is a form of rustication. Related Words : Gibbs surround, Rustication


One of the supports of a roof, running from the ridge to a wallhead in a gabled roof, and from the ridges to the wallhead in a hipped roof. The principal rafters are the sloping members at the outer edges of the roof trusses. They support horizontal members known as purlins, which in turn provide support for the common rafters. The sarking or battens to which the roof-covering is applied are fastened to the common rafters. Related Words : Truss, A-frame, Outriggers, Rosemary tiles

Rainwater goods

A generic name for all the components of a rainwater disposal system – gutters, hoppers, swan-necks, downpipes, drainpipe shoes, and gullies, and their fittings. Related Words : Swan neck, uPVC

Reconstituted stone

A building block made of fragments of ground-up natural stone, held together with cement. In some cases only the outer face of the block is made in this way, the remainder being concrete.

Reinforced concrete

See Concrete


A continuous coating applied to masonry, brickwork or blockwork, either for protection, or for cosmetic reasons. The commonest types of render are smooth (sometimes marked to resemble stone), harling and drydash. All three types can be made with lime or cement as a binding material. Generally speaking lime renders are to be preferred to cement ones, as the latter can damage the underlying material. Related Words : Wet dash, Cement, cementitious, Dry dash, Hydraulic lime, Lime mortar, render, limewashing

Retaining wall

A wall built to hold back earth, either to secure a raised site, or to prevent material falling on to a site from above.


The sides of a window or door opening Rhone A semicircular-section gutter running along the edge of a roof, used to collect rainwater. Connected to downpipes to convey the water to ground level. Related Words : Gutter , Ogee gutter, Swan neck

Ridge, ridging

The line at which two roof-slopes (skews) meet at the highest point. Ridging is the material used to cover a ridge, though some sloping ridges have no cover. Ridging may be made of lead, aluminium, zinc, cast-iron, terra-cotta, fireclay, or stone. Sometimes ornamental details are incorporated in ridging material. Related Words : Terra cotta, Cast iron work, Cresting , Finial

Rising main

Main cold-water pipe rising up through a building to a water tank


See bull-nosed


A style of architecture characterised by the use of round arches for window and doorheads, and for vaults. Early Romanesque buildings date from the 12th and early 13th centuries, and the style was revived in the 19th and early 20th centuries.


A building trade term for a person or firm specialising in roof repairs and construction. Related Words : Slater

Rose window

A circular window with divisions radiating from the centre. In Scotland commonly a feature associated with United Presbyterian churches. See also wheel window. Related Words : Wheel window

Rosemary tiles

Small red or pink clay tiles used for roofing. They have projections on one edge which can be hung on battens fastened to the rafters. Sometimes referred to as plain tiles. Related Words : Tiles


Used of sculpture in which the subject is carved as a fully solid object, not attached at the rear to a background.

Rubble, ruble

A term used to describe all masonry which is not finely-jointed and laid in regular courses (Ashlar). Commonly encountered types of rubble are coursed, random, and snecked. In coursed and snecked rubble the stones are dressed square, and in random rubble the stones are more irregular, the spaces between them being filled with small stones known as pinnings. In Caithness and Orkney the local flagstone splits easily into slabs, and walls are frequently built up from such slabs, a technique known as flagstone rubble. In drystone rubble there is no mortar in the joints. Even where a wall is faced with dressed stone, the interior face is frequently built of random rubble. Related Words : Pinnings


A term used in classical architecture to describe the emphasis of regular masonry by forming the edges of individual stones. In 18th century buildings the quoins are frequently emphasised by chamfering. The lower parts of classical buildings often have the horizontal joints channelled. There are numerous other ways of applying rustication, too complex to mention here. Related Words : Quoins


A stone forming part of the side of a window or door opening.

Sacrificial flashing

Lead flashing at the foot of a slate slope where it meets a lead roof or gutter, to take the wear of the water running off the roof Saddle bar A horizontal metal bar set across a window opening filled with stained or leaded glass. Copper wires soldered to the cames are used to tie the window to the bar, thus supporting the leadwork of the window.

Saddleback tower

A tower which terminates in a small pitched roof.  


A common type of building stone. Most sandstones are ‘freestones’, that is, they can be cut into blocks without any very obvious grain. Some sandstones are soft, and decay rapidly, others can be very hard. Cream-coloured sandstones were formed under water, and many of the red sandstones show evidence of having been formed of windblown material. When indenting new stone into an existing wall the replacement should resemble as closely as possible, both chemically and in appearance, the surrounding stone. Related Words : Whinstone


In Scottish slated roof construction, the timber boarding to which the slates are nailed. Related Words : Nail sickness, Vegetation

Sash and case window

The commonest form of ‘traditional’ window in Scotland, in which two sections of glazing are mounted into frames (sashes) which can slide past each other in a case. The weight of each sash is counterbalanced by a weight (sash weight, linked to it by a cord running over a pulley, so that when opened the sashes stay in place. Each sash weight runs up and down a slot in the side of the case. Where sash windows have been installed in an historic church they should be retained, and repaired if necessary.

Services engineer

See Mechanical and Electrical Engineer.

Skew, skewput

The term skew has two meanings in the building trades:1. One slope (pitch) of a roof, and2. The upper edge of one side of a gable, especially the top, sloping course of an exposed gable head. A skewput is the bottom stone of a skew. In late-18th and early-19th century churches the skewputs are sometimes made with carved scrolls, or simply rounded on their upper faces – scrolled or rolled skewputs. If water is penetrating a gable, it frequently comes from skews where the pointing has worn away. Related Words : Fillet, Gable, gabled, Graded slates, Pitched roof, Ridge, ridging, Snowboard, Water gate, Parging, Urn


The spreading of mortar over the face of a wall, adjacent to the joints in the masonry. In a wall made of hard, non-porous stone, slaistering with lime mortar can help rainwater to evaporate, rather than penetrating to the inner face of the wall.


A building trades craftsman or firm specialising in the repair and construction of slate roofs. Not all roofers are skilled in slating, and vice versa.


Slate is a rock formed by subjecting fine soil to heat and pressure. It can be split into fairly thin layers. There were historically many kinds and colours of slates used for roofing churches. The commonest were West Highland, or Scotch slates, from Argyll, bluish grey in colour, and Welsh slates, thinner, and usually grey or purplish. Greenish slates were quarried near Aberfoyle, or brought from Cumberland. More recently Spanish and Chinese slates have been imported, but their durability is questionable. In repair work every effort should be made to match the existing slates. In Scottish weather thin slates are easily damaged, and should be avoided. Related Words : Damp-proof course (DPC), Graded slates, Nail sickness, Stone slab roof, Stone slate roof, Water gate


Snecked rubble is a form of wall construction in which squared and often finely-dressed stones are laid in an irregular manner. The coursing is broken up by smaller stones called snecks. The surface of stones in a snecked-rubble wall is often stugged.


A projecting board mounted along the line of a roof skew so as to slow down snow sliding down the skew.  


Where there is no main drainage, rainwater from a roof can be channelled into a hole filled with coarse gravel, from which the water can gradually soak into the surrounding soil. This is known as a Soakaway.


The underside of an arch or door or window opening. Related Words : Vault

Soil pipe

A vertical pipe linking a water-closet or urinal into a sewer. It will extend above the eaves of the building, and have an open top, sometimes with a ventilating cap.


In law, the solum of a building is the area it covers, measured from the outer edges of its foundations. It is sometimes used to describe the damp-proofing of the surface of the ground under the floor of a building.


The roughly triangular space between arches, or between an arch, its abutment, and a built edge above.  

Spire, spirelet

A pyramidal extension from a tower, usually four or eight-sided. A spirelet is a small spire. Related Words : Belfry stage, Finial, Lucarne, Steeple, Fleche

Stained glass

Panels made of glass of different colours to which painted decoration has been applied. The pieces of glass are joined together by cames. The lines of the lead cames are known as lead lines. If the glass is not painted, the panel is said to be made of leaded glass. Related Words : Weldmesh, Cames, Polycarbonate sheet,

Stainless steel

See steel.


A form of iron containing a small proportion of carbon and other elements. The carbon hardens and toughens the material, which is widely used in structural engineering. Steel is also used to make gates and railings, corrugated ‘iron’, nails, protective grilles, and in plastic-coated form is used as a roof covering. Stainless steel is an alloy of iron with chromium and nickel, used in sheet form as a cladding material, and also used for making nails for roofing. Related Words : Terne coated steel, Corrugated iron, Galvanised mesh, Georgian wired glass, Zinc


Often used as an equivalent term to spire, but also specifically used as part of the term ‘crown steeple’, and to refer to the classically-inspired vertical features built from the mid-18th to the mid-19th century. Related Words : Belfry stage, Finial, Louvres, Louvre

Stone slab roof

A way of protecting the top of a vaulted roof. Carefully-cut slabs of stone are laid so that alternate sloping courses overlap each other, and the slabs in each course also overlap each other, as in a slate or tile roof.

Stone slate roof

A roof covered with split stone, laid as for true slate. Stone slates are thicker than true slates  

String course

A band of stone or brick which projects from the face of a wall. String courses may be stepped up and down. They may be plain or moulded. They can be purely decorative, but can also help to shed water from the face of the wall.

Structural engineer

An engineer whose responsibility is to calculate or assess the strength and stability of building structures, working alongside architects.


Used to describe a flat stone surface which has had regularly-spaced small indentations made on it.


As the term suggests, a roof covering an offshoot from the main body of a building. Related Words : Gablet Swan neck An angled section of pipe, usually linking a rhone to a downpipe.

Tabernacle (tin)

A name given to a corrugated-iron clad church building. The word tabernacle is also used in Catholic churches for a chamber with a door, used for the Reservation of the Host. Related Words : Corrugated iron 


The coating of a section of a wall with an impervious material to prevent water penetrating it.

Terne coated steel

Steel coated with an alloy of tin and lead, used as a roofing material.

Terra cotta

Used of fired clay pieces with a fine red surface, made at a high temperature so that they are dense and impervious to water. In church buildings terra cotta ware would be most commonly used for roof ridging and finials. Related Words : Finial, Ridge, ridging


Tiles are pieces of roofing material, regular in size and shape so as to allow a roof to be covered evenly and rapidly. Tiles may be made of fired clay or of concrete. Clay tiles may be flat (rosemary tiles), of an S-shaped section (pantiles), or of some special section. They are usually fixed on battens. Concrete tiles may be flat, and diamond-shaped, or profiled in some way, for example to resemble pantiles. Concrete tiles are heavier and less durable than clay tiles or slates. Related Words : Batten 

Toughened glass

Glass treated to be resistant to impact. It is designed to break up into tiny fragments, rather than to splinter.


The pattern of stone, wood or iron strips used to subdivide a large window opening into smaller sections. Tracery is used to describe the pattern of major subdivisions of a window. Related Words : Light (window) 


A projection from the main body of a church. In a fully-developed Latin cross-plan church there are two transepts (‘north and south’) forming the arms of the cross. In some buildings intended to be cruciform the long nave was never built. In many post-Reformation churches the ‘transepts’ are projections built primarily to house side galleries. 


A cross-member in the subdivision of a window opening. 


A wooden or metal flat frame, usually made of triangular elements. In church building a series of trusses, with rafters and purlins, forms the supporting structure of the roof. Related Words : Wall plate


The masonry or brickwork inside a pediment, or the head of an arch, sometimes filled with sculpture.


An extension of a part of a wall above the edge of the roof. A flat roof will frequently have upstands round its edge. Related Words : Georgian 


Ultra-high-density polyvinyl chloride, a rigid plastic material (polymer) with sufficient strength and weather resistance to be used for external building work. The main applications of uPVC are in window and door construction, in forming fascias, and in the making of rainwater goods. 


In architecture, an urn-shaped solid object, usually fixed to a wall-head, or to a gable at its apex or at a skewput, to give a richness to a building.

Valley, valley gutter

A valley is the term used to describe where two roofs meet at the lower line, either on a slope, or horizontally. The line of intersection is a weak point in any roof system, and potentially a point where water can penetrate the building. Valley gutters are often formed in lead. They need regular monitoring. They should be kept clear of leaves and other debris. Fine cracks in the leadwork can cause water penetration, and hence rot in the underlying timber Related Words : Plastique


An arched cover for an enclosed space. The simplest form of vault is supported on each side by a continuous wall, and is known as a barrel vault. Most barrel vaults are round-arched, but a few are pointed-arched. In more complex vaults there is a framework of dressed-stone ribs, acting as a frame, with rubble filling the spaces between the ribs. Sometimes decorative ribs are applied to the underside – Soffit – of a barrel vault. Timber and plaster ceilings are sometimes made to resemble vaulting.


In building conservation terms, plants growing, in an unintended way, on a building. Seeds carried by the wind, or by birds, can germinate in small pockets of soil in gutters, in open joints, or in valleys. Their growth can often damage masonry directly, or allow water to penetrate a building. Moss on slate or tile roofs can encourage rot in sarking. 

Venetian window

Actually three windows, a taller round-headed window, flanked by shorter flat-headed ones. Sometimes the outer windows are blind 

Ventilator, ventilating brick, grille

Devices to encourage air to circulate in a building. Under-floor ventilators help to keep rot at bay, and should be kept clear. Roof ventilators keep the air in the internal spaces fresh, and help to avoid condensation, and the growth of fungal infection. They should not be blocked up. Related Words : Fleche 


A window or ventilating opening with curved sides, meeting at a sharp point at the top and bottom.


Wooden panelling lining the lower part of an internal wall. 

Wall plate

A beam, usually of timber, resting on a wallhead, on which the lower ends of the roof-trusses rest

Wall ties

In a cavity wall, the metal strips which link the inner and outer walls Related Words : Cavity wall 


The top of a masonry wall. On the inside this can sometimes be seen from the roofspace. Related Words : Abutment, Copes, coping, Crenellation, Damp-proof course (DPC), Eaves, eaves band, Gablet, Gargoyle, Machicolation, Ogee gutter

Water gate

A channel, usually lead-lined formed between a skew and the roofing material (slate etc). 


A wire lattice in which the horizontal and vertical wires are welded together where the meet. Weldmesh can be powder-coated with resin, and used to provide almost invisible protection to stained and leaded glass windows. Related Words : Galvanised mesh

Wet dash

As opposed to dry dash, a render in which the particles of aggregate are covered in the binding material, with the mixture dashed on to the wall surface.

Wheel window

A circular window with the glazed area divided into segments by radiating ‘spokes’. Almost the same as a rose window Related Words : Rose window 


A hard stone, formed by molten or semi-molten volcanic rock welling up through the surface rock. Whinstone is usually dark in colour, and cannot be dressed to a fine finish. When used in church buildings it is usually set in a framework of sandstone dressings. 


Part of a building subsidiary to its main body. Related Words : Aisle, Jamb

Wrought iron

A form of iron containing little carbon, but having then layers of slag between fibres of metallic iron. It is resistant to corrosion, and is tough, rather than brittle. Used to make gates, railings, ironmongery and nails. Common in buildings built before the 1930s, but now difficult to obtain, and expensive. Related Words : Cast iron work, Finial, Zinc


A softish grey metal, used in three ways in church buildings: 1. in pure sheet form to make ridging for slate roofs, or as a roof covering in its own right.2. In pure rolled sections, to make glazing bars for small-paned glazing. 3. As a coating – galvanising – for wrought-iron or steel, Typical applications are to coat ‘corrugated iron’, gates and railings and other exposed steelwork. Also used to coat slating nails. Zinc is more chemically reactive than the underlying iron or steel, so galvanising deters rusting. Related Words : Corrugated iron, Galvanised mesh, Ridge, ridging, Flashing