The Self Build Self Help Site
Glossary

Welcome to the Self-Build Self-Help site's glossary of building terms. Follow links in this document for further information :

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A B C D E F G H I J K L M
N O P Q R S T U V W X Y Z
A

aggregate the generic term for coarse ballast material - crushed stone, gravel and chippings etc. For a good list of aggregates, and more, see AJ McCormack & Son - pavementexpert.com

asbestos Asbestos can be found in any building built before the year 2000 (houses, factories, offices, schools, hospitals etc). Due to its properties of being light, excellent insulation and heat resistance, ability to be woven, cast into sheets and even sprayed on, it has had many uses in the building industry - until its extreme dangers to health were identified - it causes around 5000 deaths every year. There are many organisations that will help people who have been exposed to asbestos, via our Mesothelioma page

awning window a window style where the windows open by way of hinges affixed at the top (also called simply "top opener").

B

back drop manhole an inspection chamber converted to allow a gradient of greater than 1:40 for foul water drains photograph available from this link more information available from this link picture gallery available from this link

backfill to fill a trench once a foundation has been completed, or drains laid etc. picture gallery available from this link

baluster the slender pillar, a set of which supports a stair handrail, also called spindles picture gallery available from this link

balustrade an ornamental parapet, often made of stone, composed of a number of balusters topped with a rail or coping

band course a horizontal band on the face of a building or structure to create a decorative effect. May be created from a course of bricks of different colour or bond, a band of stone, or a raised band of render

barge board the board mounted on a 'ladder' under the roof at a gable end with a soffit below picture gallery available from this link

batten timber strips, nailed onto the rafters, onto which slates or tiles are fixed picture gallery available from this link

bed joint the horizontal cement joint between bricks or blocks

bell bead a metal beading used on external render to bring the render out slightly to provide a "drip", usually towards the base of a wall, and provides a demarcation to the plinth. It is also often used higher up the wall to break up large areas of render to avoid cracking and to provide a decorative effect. The beading comes as galvanised, stainless steel or plastic. If building within 7 miles of the sea, stainless steel or plastic is best.

blockboard a sheet material made up of a core of softwood strips sandwiched between veneers of hardwood. Not suitable for external use due to the interior grade adhesive used.

bottle gully used to remove surface water from the curtilage, and usually takes water from a downpipe

Brownfield land land which has previously been developed

Building Regulations national standards which apply to all types of buildings, from major new developments to a home extension more information available from this link

C

casement window a window style where the windows open by way of hinges affixed to a vertical side.

caulk a mastic filler used to fill the join between skirting board/architrave and the wall and, externally, to fill the join between a soffit and wall more information available from this link

cavity tray a "tray" to catch water that might seep into a cavity wall and send it back to the outside via a weep hole. May be a sheet of DPM incorporated under a window opening or a manufactured tray for where a roof abuts a wall photograph available from this link

For chimneys, a lead tray will go right through the chimney to provide a complete barrier - more information available from this link

cess pit a sealed container into which the flow from the foul drains is stored until it is periodically removed by a tanker - for properties not connected to a public sewer (see also septic tank)

chalk line A line made on the target material, by snapping a taut cord which has been dusted with chalk. Proprietry chalk lines can be bought, which enclose the cord in a refillable container of chalk. Often used on a plasterboard ceiling for lining up the retaining screws, or for aligning ceiling/wall paper

chipboard chipboard is a wooden sheet material made up of small wooden particles being bonded together under high pressure, reslting in a smooth surface finish. There are different grades but the most common nowadays is flooring grade.

climate change homeowners are becoming more concerned about energy efficiency and the cost of energy. The style of houses is changing in order to adapt to the new conditions. How a home is designed and the materials utilised can affect a number of areas linked to climate change. more information available from this link

conduit a tube or trough, usually set into a wall, for protecting electrical wiring.

code 3 means that the lead weighs 3lbs per square foot, code 4, weighs 4lbs per square foot etc

collar beam a horizontal timber(usually) member that connects rafters on opposite sides of a roof to stop the roof from spreading. Often employed where normally placed roof joists would be too low. photograph available from this link

colonnade a series of columns with an entablature above

combination boiler a domestic boiler which heats water on demand - therefore it doesn't have an external hot water tank but does have a small tank within the boiler enclosure to give some hot water as soon as a hot water tap is turned on. The boiler then fires up to continue the supply. Not suitable for houses where a number of en-suites/bathrooms exist as the supply may be inadequate. For more information on this and other boiler type see the Heating & Hotwater Industry Council site

condensing boiler the most efficient boiler which has a heat exchanger which removes heat from the waste gases to maximise efficiency. For more information on condensing boilers see plumbingpages.com and the Heating & Hotwater Industry Council site.

coping the top course of masonry in a wall - usually sloping concrete stones, overhanging the wall face to throw water away from the wall face (once weathered or twice weathered). more information available from this link

For a comprehensive brochure on coping stones and other concrete building products, see the Allen Concrete Limited pdf

corbel a projection of stone, brick or timber, built into and jutting out from a wall to support a weight

cornice

counter batten battens that cross other battens, joists, rafters to mount plasterboard or other sheet materials, in order to cover the existing material, lower the height etc.

course a row of blocks, brickes or roof slates/tiles

Cupola a small rounded dome forming a roof, or part of a roof

curtilage the area immediately attached to a dwelling - such as a pathway

D

dado the lower few feet of a wall, faced with wood or coloured differently to differentiate it from the upper part of the wall. The dado is often delineated by a dado rail

dormer a projecting vertical window built into a sloping roof

double lap normally used for slates so that each course overlaps the course below and some of the course below that. In this way, there is no way for water, running down the gap between slates, to penetrate through the slates (see also single lap)

dressed stone stone that has been trimmed and squared so that it has a smoothish, flatish face and roundish edges - ideal for building walls that will have a face showing

dresser a wooden tool for dressing lead i.e. for moulding sheet lead into valleys, tops of valleys etc

E

eaves the lower overhanging edge of a pitched roof

efflorescence Natural salts, which occur in the material used to construct bricks and blocks, will sometimes be washed out by rain and appear as white stains. Can be minimised, but not usually eliminated 100 per cent, by using a special sulfacrete cement. If the white stain is not easily brushed off it might be lime staining, which is more difficult to get rid of.

Energy Performance Certificates (EPCs) are, from October 2008, required by law to be provided for all new houses. They provide a measure of the energy efficiency of a building as well as the environmental impact as measured by CO2 emissions. They provide an 'A' to 'G' rating for the building, with 'A' being the most energy efficient.

entablature the part of a structure immediately above a column, consisting of architrave, frieze and cornice

expansion joint a fibre strip used to separate large expanses of concrete slab into areas to prevent cracking from expansion due to temperature changes. Stainless steel expansion joits are used to separate large areas of render or plaster.

F

facing brick the outer side of brickwork that will be on show and which will therefore need to be built neatly. The term 'face work' also applies to brickwork on show.

fascia the vertical board secured to the ends of the rafters at the eaves to which the guttering is fixed

finial an ornate ridge tile at the end of a pitched roof, or the apex of a pediment or roof tower. Originally they were used to provide extra weight to hold the more vulnerable ridge tiles down.

fireback a heat resistant shield built at the back of a fireplace to protect the walls and reflect heat back into the room. Traditionally made from clay, they are also manufactured in fire resistent cement, cast iron and even stainless steel.

fire cement an adhesive cement preparation used to cement together chimney flue liners and fire backs and seal joints in stoves where required. It usually comes in small tubs ready mixed.

flashing a strip of lead to prevent the ingress of water at the joint made between a verticasl surface and a roof

flaunching the mortar fillet around the base of chimney pot on top of a chimney stack, designed to both hold the pot in placed and throw off water so that it does not penetrate the stack

flue liners eiher made of concrete or clay, cylindrical liners for creating a flue within a chimney for taking fire gases to the atmosphere above the roof line more information available from this link

footings the concrete strip which supports the walls of a building. The footings are prepared in two main methods:

foundation the blockwork, building off the footings, up to the DPC

frieze

G

gabions are used to stabilise and strengthen embankments and made fron welded wire mesh filled with rock

gable the triangular upper part of a wall at the end of a pitched roof

gable ladder the wood , incorporating the end trusses (resembles a ladder when assembled), that supports the roof slates / tiles to provide an overhanging verge at the gable end

gable roof a small triangular shaped roof that covers a dormer window that is set in the pitch of a roof

gallows bracket a bracket, made of wood or steel, to support a structure, with the horizontal member supported by an angled piece. Often used to support a porch roof or, for example, in steel to support a chimney stack where the chimney breast has been removed.

gargoyle a grotesque spout, usually with a human or animal, head or body, protruding fro a gutter to carry water away from the wall. In modern building, often used to describe a simple spout to carry water away from a wall

gauge usually applied to the interval between battens on a roof but may also be the term applied to the measurement between courses of brick or blockwork (which can only be varied by differing the thickness in the cement "bed"

geotextile a strong woven plastic material that prevents the intermixing of substances either side, yet permits water to flow freely

going the tread of a stair step

Greenfield land A site that has had no previous development on it

H

header a brick laid with the end showing

header bond a wall where every facing brick is a header

header a short joist attached to trimmer joists to create a space for a chimney or stairwell

head lap the shortest distance from the butt edge of an overlapping slate / tile to the upper edge of a slate / tile second course below

hip the external angle formed at conjunction of two sloping sides of a roof

hip iron a metal stay, curled at one end, which is nailed onto the hip board to keep the hip ridge tiles in place photograph available from this link

hip roof a roof sloping on all four sides

hip tile a concrete or clay tile, shaped at an angle to cover the angle at a hip - find more about tiles from the suppliers list in the Product Finder section

I

I-Joist a cost effective alternative to ordinary wooden joists. An I-joist is a structurally engineered joist which is very strong and has a number of advantages over wooden - see the Melingoed Ltd site for more information

inspection chamber a chamber that gives access to a segment of a drain or sewer. Traditionally made of brick, now are made of pre-cast concrete sections for large inspection chambers and plastic sections for smaller chambers. Can be used to create a back drop manhole.

intumescent seal the seal around all edges of a fire door which will swell up in a fire and prevent the movement of air and fire between the door and the frame

J

jamb the side post of a doorway or window

joist one of a number of parallel timbers that stretch from wall to wall to support the floor / ceiling (see also I-Joist)

joist hanger a metal strap used to attach and support the ends of wooden joists:

joist shoe a plastic shoe that is fitted over the end of a joist to provide an airtight seal between the joist end and the surrounding mortar where it is bedded into the inner leaf block wall

K

key brick, block or stone the centre brick, block or stone at the top of an arch

L

land drain a corrugated (for strength) flexible plastic pipe, incorporting many small holes, for draining land. Often used behind, and at he base of, retaining walls to remove ground water. photograph available from this link

laminate flooring a manmade material as an alternative to real wood, carpets etc. which comes in a variety of finishes such as to look like wood or tiles. How does it compare with real wood? --> more information available from this link

lead tray for chimneys, a lead tray will go right through the chimney to provide a complete barrier - more information available from this link

Lime staining this is a result of lime (calcium hydroxide) migrating to the surface of the brick where it reacts with carbon dioxide in the air to form calcium carbonate, which is insoluble and therefore will not be removed by washing. Unless it is brushed off as it appears, it builds up quickly into hard deposits which are very difficult to remove and may require acid treatment - best done by a specialist.The calcium hydroxide can come from the cement or from water in the blocks or ground water, which is why it is often seen on retaining walls. photograph available from this link See also efflorescence

lintel a beam (steel or reinfoced concrete) placed over an opening in a wall, with sufficient bearing at each end so that it provides a support for the wall above

lost head nails round wire nails with heads only slightly larger than the nail shank - so that the head can be buried in wood, eg architrave, and then filler applied so that the nail does not show after painting/varnishing

M

Mansard roof a roof in which each face has two slopes, the lower one steeper than the upper

margin the measurement of the exposed area of a slate or tile - the measurement is the same as the "gauge"

Mesothelioma a rare form of cancer found in the thin lining of the lung, abdomen and heart, due to exposre to asbestos. There are many organisations that will help people who have been exposed to asbestos, via our Mesothelioma page

mullion a vertical bar dividing the lights in a window

multi-foil insulation an insulation product that uses layers of polyethylene coated foils spaced with wadding and closed cell foams that are very efficient in reducing radiant heat transfer and are easy to install and increasingly used as an alternative to cavity insulation and glass mineral wool insulation on the underside of roof rafters etc. more information available from this link

muntin the central vertical timber frame member in a panel door

N

nail sickness usually found on very old roofs where the nails have corroded and fail to hold the slates in place effectively

newel post the large post that anchors the handrail at the bottom and top of a staircase and also at points where a stair changes direction

nosing the rounded leading edge of a step

O

once weathered a coping stone which has just one slope on the top surface for water runoff. Usually, the slope runs water away from the face, to avoid unsightly staining. See also twice weathered.

P

pantile a roof tile which, in cross section, has an ogee shape (S shape), with the upper curve being much larger than the lower - find more about tiles from the suppliers list in the Product Finder section

parapet a low wall at the edge of a balcony, roof or bridge

patination oil an air drying fluid that is painted on lead work to prevent the white carbonate which will otherwise form and then any water run-off will stain slates etc

pediment a trianguler face crowning the front of a building, traditionally in a Grecian style photograph available from this link

perp short for perpend (which is probably derived from perpendicular), the vertical cement joint between bricks or blocks

pier cap a square coping stone to sit atop a masonry pier, at the end of, or midway along, a wall. Slopes on four sides to run water off.

pitch a black or dark brown tarry substance, liquid when hot but hard when cold, used to fill cracks in tarmacadam pavements and roads

pitch the slope of a roof expressed as the ratio of the rise to the span - a 40 degree pitch is a common pitch

pitched roof a roof which has one or more surfaces sloping at an angle

plinth a section of wall formed from the ground and rising a few courses, it is distinguished from the upper wall by a slight projection, or recessed under a bell bead, or by some difference in colour or material

portico a roof supported by columns, often attached to a building to serve as a porch

purlin a horizontal structural member in a cut timber roof that supports the rafters, usually midway . The purlin itslef is usually supported at its ends by being incorporated into blockwork. photograph available from this link

Q

quoin a corner brick. A squint quoin is a corner brick with an exterior angle greater or less than a right angle.

The term quoin is most often used for a decorative brick or stone, raised from the face of the wall.

R

Radon a naturally occuring radioactive gas, derived from Uranium, which is present in all rocks and soils to differing extents according to location. Different levels of gas require different methods of protection. more information available from this link

rafter a sloping roof timber onto which the slate/tile battens are nailed. The term applies to both the sloping elements of roof trusses as well as cut timber roofs

rail a horizontal piece of timber as part of the frame of a panelled door:

retaining wall a retaining wall is one that holds back an area of elevated ground from a building or part of the plot, either above the proposed house or below it. more information available from this link

reveal the end of a block / brick wall where it creates an opening for a door or window - internally and externally

ridge the upper junction of two slopes of a roof, which will be rain proofed with ridge tiles

ridge board the board along the line of the ridge - not usually found in trussed roofs but found in cut timber roofs where the rafters are fixed to the board on both sides picture

ridge tile an angled or semicircular tile used to seal the top of pitched roofs and hips. Angled ridge tiles come in a small range of angles to match the pitch of the roof picture gallery available from this link

riser the front vertical section of a stair step

roofing felt the material stretched over rafters and held down by the battens, which forms a secondary barrier to the ingress of water. Usually architects require a breathable membrane which will allow air to cross it to prevent the formation of damp within the roof space. picture gallery available from this link

S

sarking another name for roofing felt. picture gallery available from this link

sash window a window style where the windows open by sliding up and down within tracks at the side. The weight of the window is counterbalanced by lead or cast iron weights contained within the side boxes.

scarf joint either of the chamfered or cutaway ends that fit together to form a scarf joint 2: a timber joint made by chamfering or halving two pieces of timber and fixing them together, in-line

scalpings typically made from crushed limestone, usually 40mm down (to dust) and used as a sub-base

scotia decorative wooden beading, concave in profile. Often used on newly laid wooden floors to cover the gap between the floor
and skirting board. photograph available from this link

SEDBUK a rating system to provide information on the efficiency of heating boilers - for more information see the Boiler Efficiency Database

septic tank traditionally used in properties not connected to public sewers, to receive the contents of the foul water drains, which is detoxified through bacterial action and slowly released into a a soakaway. They are now frowned upon by the authorities.

sheradised nails nails that have been made rust proof through a proces that incorporates a zinc covering - cheaper than stainless steel nails

shingles thin strips of wood used in overlapping way to provide a roof covering. Can also be made of asphalt

single lap usually used for concrete and clay tiles where they overlap only some of the tile below, and which prevent the ingress of rain due to the intelocking shape of the tile

skew nailing nailing an item to another by driving nails at an angle, for example nailing trusses to a wall plate with, usually 3" or 4" nails - this application can be replaced by the use of truss clips

sleeper wall a wall that only supports a floor, and hence does not rise above the floor - usually found in older houses, and internal walls beneath block and beam floors in modern houses

slip block a thin block used to fill the gap between the underside of beams (for beam and block floor) and the wall on which they are supported

soffit the horizontal board used to seal the space between the back of the fascia and the wall of the building. picture gallery available from this link

soil stack a vent pipe that penetrates the roof

stile the outer vertical timber frame member in a panel door

stretcher a brick laid with the long side showing

stretcher bond a wall where every facing brick is a stretcher

string stringer board - the board that runs from newel post to newel post on a stair, upon which the spindles are supported. The wall string is the board that runs against the wall, to which the stair treads and risers are fixed. picture gallery available from this link

structurally engineered timber components such as joists and wall panels, can be made from such timber, which is a combination of chipped softwood and engineered composite panels. The strength is sufficient for load bearing components.

stucco kinds of plaster or cement for the final coating of wall surfaces

sulfacrete cement a cement used to avoid formation of white deposits on the face of the bricks, caused by naturally ocurring sulphates in the bricks.

T

Thermostatic Radiator Valve (TRV) should be put on all radiators other than in the room where the room thermostat is put. They monitor the room temperature and control the radiator valve accordingly.

threshold the bottom of the door frame for an external door - the door sill

tingle a small strip of lead, zinc or copper which is nailed to a batten at the lower edge of a displaced slate and turned up to hold the slate in place

trimmer a joist to which a header joist is attached in order to create a space in the joist structure for a chimney or stairwell

truss a factory made roof frame, replacing the timbers for a traditional "cut timber" roof picture gallery available from this link

truss clip attaches roof trusses to wall plates

twice weathered a coping stone, the top of which slopes in both directions, to throw water away to both sides. See also once weathered.

U

utility bar a smallish metal bar, formed and notched at each end to provide leverage for removing nails, prising etc. photograph available from this link

U-value a measure of the the rate of heat flow through any building component - doors, windows, walls, roof etc. The smaller the u-value the better.

V

valley the conjunction of two pitched roofs, down which rain will flow before emptying into a gutter. Usually lined with lead or may be made with clay or concrete valley tiles picture gallery available from this link

valley tiles clay or concrete tiles which are shaped to form a valley, which intelocking with the rest of the roof tiles, create a "seamless" conjunction

vapour barrier usually composed of polythene sheeting which is designed to protect underlying material from condensation where warm, moisture-laden air comes into contact with a colder surface picture gallery available from this link

vent an outlet within a wall, roof or soffit to allow air to be released. The vent is usually a plastic grill.

verge the edge of the slates / tiles that project over the top of the wall at the gable end

vermiculite a very lightweight, high temperature insulant for insulating chimneys and mixing with cement to support clay flue liners within a chimney breast. It can also be used to fill the void between an inserted flue liner and existing flue. Very little water is used to make up such a cement mix.
There are other uses, such as to create lightweight structural grade concrete and as a base coat for stucco finishes.

voussoir wedge shaped stone for forming an arch

W

wall plate the timber that is bedded on the top of the internal leaf of a wall, onto which the rafters are fixed - skew nailed or fixed by truss clips and sometimes bird-mouthed

weep hole holes provided in walls to allow water to drain away. Usually in walls to:

wind bracing nailing, usually, 4" * 1" sawn timber, diagonally across the inside of roof trusses to prevent lateral movement photograph available from this link

winder a tapered stair tread, necessary to allow a turn in the stairs - hence a "winder stair" is one with a turn in it

window board another term for the internal window sill, normally made of wood, either softwood such as pine or MDF and, occasionally, a hard wood such as Oak. photograph available from this link It makes things much easier if much of the preparation is done before installation - see Hints & Tips/Doing Stuff/Painting and Decorating

X

Y

Z

Zero carbon the Government requirement that, by 2016, all new homes must be built so that there are no net carbon emissions from all energy use, measured over a one year period