Building Terms
Whilst we endeavour to avoid jargon in our Reports, the use
of some technical terms is unavoidable. Some common building terms are
listed below for your information:
Abutment - an intersection, usually between a
roof and a wall.
Access Tower - a portable scaffold that allows
quick and cheap access to high areas.
Aggregate - broken stone, gravel or sand used
with cement to form concrete. Aggregates may be coarse or fine and are often
used in the construction of "soakaways".
Airbrick - a perforated brick, terracotta or
plastic vent built into a wall for providing ventilation. Often used to
ventilate the underside of timber ground floors, fireplaces or a roof space.
Apron - a metal strip, usually lead or zinc, used as a seal. Often fitted to
chimney stacks and tile hanging. Also a section of wall below a window.
Apotropaic Markings - Apotropaic, ritual or
'witches' marks were carved into doors, windows and fireplaces where air,
and therefore witches, could enter a building to protect them from such evil
spirits. Although common on doors and jambs of doorways, they are most
likely to be found around fireplaces. The most common markings are
interlocking circles (some carved to create a six-petalled daisy flower
effect), concentric circles and intersecting lines creating crosses and M's
representing the Virgin Mary or double V's for 'Virgin of Virgins'.
Architrave - a moulding around a doorway or
window opening. It usually covers the joints between the frame and the wall
finish, thus hiding any shrinkage gaps, which may occur.
Asbestos - material used in the past for
insulation and fire protection. Can sometimes be a health hazard and
specialist advice may be needed if asbestos is suspected or found. Typical
locations in houses are roofs, soffit boards, textured (Artex type) ceiling
and wall finishes, rainwater fittings and older plastic tiles etc.
Asbestos Cement - cement mixed with up to 15%
asbestos fibre as reinforcement. Fragile -will not usually bear heavy
weights. Hazardous fibres may be released if cut or drilled. The material is
usually safe if left in-situ. If disposal is required the waste should be
taken to an appropriate disposal site. At present, there is no requirement
for this to be undertaken by a licensed asbestos removal contractor.
Ashlar - Finely dressed (finished) stone -
usually in high quality construction.
Asphalt - black, tar-like substance impervious
to moisture. Used on flat roofs and floors.
Bakelite - an early plastic often used in old
electrical fittings.
Ball Valve (Ballcock) - valve operated by a
ball floating in a cistern. Barge Board - a sloping board built along a
gable edge of a roof. Balanced (or room sealed ) Flue - common flue type
normally serving gas appliances, which allows air to be drawn to the
appliance whilst also allowing fumes to escape.
Baluster - a post or vertical pillar
supporting a handrail or parapet rail.
Balustrade - a collective name for a row of
balusters or other infilling below a handrail on a stair or parapet.
Batten - thin strips of timber, commonly used
to support roof tiles or slates.
Bay Window - a window formed in a projection of
a wall and carried on foundations.
Beam - a structural component spanning an
opening and designed to carry the weight of the structure above. Usually
concrete or steel in newer construction. Often timber in older buildings.
Beetle Infestation - larvae of various
species of beetle, which tunnel, into timber causing damage (often called
woodworm). Specialist treatment normally required. Can also affect
furniture.
Bellcast - thickening out of render, in a
curved shape, to form a drip to deflect water. Usually found at the base of
a wall, above the damp-proof course.
Benching - shaped concrete slope beside
drainage channel within an inspection chamber. Also known as "haunching".
Binder - a cross timber laid over ceiling
joists to reduce their effective span and prevent sagging.
Bitumen - black, sticky substance, similar to
asphalt. Used in sealants, mineral felts and damp-proof courses.
Blistering - trapped air bubbles below felt,
asphalt or painted surfaces usually indicating imminent failure of the
material.
Bond - the regular arrangements of bricks,
blocks or stones in a wall so that the units may be joined together. The
principal types of "bond" used in domestic construction being English,
Flemish, header, stretcher, rat-trap, diagonal or garden wall bond.
Bonding Timbers - timbers built into the walls
in older houses to provide restraint. Unfortunately, these can easily rot
and are often affected by wood-boring insect attack.
Bonnet tile - a hip tile with a bonnet-like
appearance.
Box Gutter - square shaped gutter, often found
behind a parapet wall.
Breeze Block - originally made from clinker
cinders (or "breeze") -the term now commonly used to refer to various types
of concrete building blocks.
Bressumer - A lintel, often timber, over a
shop front, fireplace or bay opening.
Building Paper - Heavy-duty paper, usually
incorporating a bitumen layer. Was often used as a lining under roof tiles
in the 1960's. Tears easily.
Butterfly Roof - 'M' shaped roof usually
hidden at the front with a parapet wall. The hidden central valley gutters
are often a source of nuisance.
Buttress - a wall, usually triangular in
shape, built to restrain bulging. Temporary buttresses can be constructed in
timber and are used during construction, typically if a facade is being
retained and built behind.
Carriage - A substantial timber that runs
along the underside of a staircase.
Cames - The lead bars in leaded windows.
Carbonation - a natural process affecting
the outer layer of concrete. Metal reinforcement within that layer is liable
to early corrosion, with consequent fracturing of the concrete in some
cases.
Casement Window - a window composed of hinged,
pivoted or fixed sashes.
Cavity Wall - traditional modern method of
building external walls of houses comprising two leaves of brick or
blockwork usually separated by a gap ("cavity") of about 5Omm and held
together with metal ties that can rust. The wall cavity is now usually
insulated.
Cavity Wall Insulation - filling of wall
cavities by one of various forms of insulation material: Beads -
polystyrene beads pumped into the cavities. Will easily fall out if the
wall is broken open for any reason. Foam - urea formaldehyde foam, mixed on
site and then pumped into the cavities where it sets. Can lead to problems
of dampness and make replacement of wall-ties more difficult. There have
also been some health concerns. Fibreglass - usually built-in during
construction. Mineral Wool - inert mineral fibre pumped into the cavity or
built-in during construction.
Cavity Wall Tie - a twisted piece of metal or
similar material bedded into the inner and outer leaves of cavity walls
intended to strengthen the wall. Failure by corrosion can result in the wall
becoming unstable. Replacement ties are then required.
Cesspool (cesspit) - a simple method of
drainage comprising a holding tank, which needs frequent emptying. Not to be
confused with a "septic tank" which treats waste.
Chipboard - often referred to as "particle
board". Chips of wood compressed and glued into sheet form. Cheap method of
decking to flat roofs, floors and (with Formica or melamine surface) used
extensively for furniture, especially kitchen units.
Cill - see "sill".
Cleaning Eye - sometimes known as an 'access
eye' or 'rodding eye'. An opening in a drain or ventilation pipe, covered by
a plate, the removal of which allows the drain to be rodded to clear
blockages.
Cladding - the non-loadbearing external skin of
a wall or roof used to keep the weather out.
Cob - walling of damp earth sometimes mixed
with cement, rammed without reinforcement into a formwork. This old method
of walling is known in Oxfordshire and Buckinghamshire as Wychert.
Cold Roof - a roof in which the insulation is
placed below the deck or structure. Collar Beam - horizontal tie beam of a
roof, which is joined to opposing rafters at a level above that of the wall
plates.
Collar - horizontal timber member designed to
restrain opposing roof slopes. Absence, removal or weakening can lead to
roof spread.
Combed wheat Reed - the most common method of
thatching in our area. Straw is used, rather than water reed as the name
suggests.
Combination Boiler - central heating boiler
that also provides hot water on demand, sometimes within a pressurised
system. With this form of boiler there is no need for water storage tanks,
hot water cylinders etc.
Condensation - a type of dampness caused by
relatively warm and moist air meeting a colder surface. The ability of the
air to hold water decreases as it gets colder and the excess water condenses
onto the surface. Often occurs to windows and the lower areas of walls.
Condensed water is very clean and is often associated with the growth of
black mould. Easily confused with rising damp.
Conduit - usually a metal or plastic tube used
to protect electrical cables.
Consumer Unit (distribution board) - fuses or
circuit breakers providing short circuit protection to an electrical
system.
Coping/Coping Stone - usually stone or
concrete laid on top of a wall as a decorative finish and designed to stop
rainwater soaking into the wall.
Corbel - projection of stone, brick, timber or
metal jutting out from a wall to support a weight above.
Cornice - moulding at the junction between a
wall and ceiling. Can also include a moulding at the top of an outside wall
designed to project and throw raindrops clear of the wall.
Course - horizontal layer of bricks, blocks,
slates etc. including any mortar laid with them.
Cover Flashing - vertical flashing overlapping
the vertical upturned parts of a roof covering or other flashing.
Coving - curved junction between wall and
ceiling.
Cowl - a cover often fitted to an unused
chimney flue to prevent rain penetration and also provide some ventilation.
Crazing - hairline cracks on the surface of
concrete, render or plaster usually of random pattern over a large area.
Usually indicates failure.
Crown - the top of an archway.
Cruck Beams - pairs of curved timbers, which
run from ground level and meet at the ridge.
Cut Valley - a gutter at the junction of two
roof where the slates or tiles are cut to meet on the valley line.
Dado Rail - a moulding fixed to the wall or
capping panelling and forming the top most part of a dado. Originally
designed to avoid damage to the wall where people or furniture brushed
against it.
Damp-Proof Course (or DPC) - layer of
impervious material (mineral felt, PVC etc) incorporated into a wall and
designed to prevent dampness rising up the wall or lateral dampness around
windows, doors etc. Various proprietary methods are available for
damp-proofing existing walls including "electro-osmosis" and chemical
injection.
Damp-Proof Membrane - horizontal layer of
impervious material (usually polythene or bitumen). Incorporated into floors
or slabs.
Deathwatch Beetle - (Xestobium rufovillosum).
Extremely serious insect pest that attacks structural timbers. Usually
affects old hardwoods with fungal decay already present.
Distemper - old form of painted decoration
made from chalk and animal glue.
Dormer - a window built out from a roof slope.
Dormer Cheek - the vertical side of a dormer
window.
Downpipe - vertical pipe which brings rainwater to
ground level from roof gutters or waste water from hoppers.
Double Glazing - a method of thermal and sound
insulation usually either with sealed units - two panes of glass fixed and
hermetically sealed together; or secondary - a second "window" positioned
inside the original window.
Double Hung - a window in which the opening
lights slide vertically within a cased Sash Window frame, counter balanced
by weights supported on sash cords that pass over pulleys in the frame.
Drip - groove under an overhanging edge (e.g.
window cill) designed to stop water running down the face of the building.
Dry Rot - (Serpula lacrymans). A very serious form
of fungus that attacks structural and joinery timbers, often with
devastating results. Flourishes in moist unventilated areas, but the spores
can survive in dry conditions.
Eaves - the overhanging lower edge of a roof.
Efflorescence - powdery white salts crystallized
on the surface of a wall as a result of moisture evaporation. Unsightly, but
causes no damage.
Engineering Brick - particularly strong and dense
type of brick, often used as a damp proof course in older buildings.
English Bond - a traditional form of solid wall
construction with brick courses (layers) laid with headers (the short end)
laid alternately with stretchers (the long side).
Expansion Tank - small tank required for many
central heating installations to provide water for the system and to allow
for overflow.
Fall - a slope, typically to a 'flat' roof,
designed to allow water to drain away.
Fanlight - a window above a door or casement.
Fascia - a board fixed to the rafter ends along the
roof eaves - usually used to fit gutters.
Fibreboard - lightweight board material of little
strength, was used in ceilings, or as insulation to attics. Considered to be
a fire risk and usually best removed. Some of the paper backings to
fibreboard can contain asbestos.
Fillet - mortar used to seal a junction, usually
between roofs and brickwork in older property. Lead flashings are now
usually used.
Flagstones - large stones used as an attractive
floor finish.
Flashing - a seal, usually between a roof and
wall or chimney. Normally constructed in metal, but can be felt or
proprietary material. Cement flashings are usually called fillets.
Flaunching - mortar weathering on the top of a
chimney stack surrounding the base of the chimney pots to throw off the rain
and thus prevent it from saturating the stack.
Flat felt roof - common type of flat roof made
from built up layers of felt. Fairly cheap, but often fails suddenly and
needs regular re-covering.
Flemish Bond - a traditional form of solid wall
construction with the bricks laid with headers (the short end) laid
alternately with stretchers (the long side).
Flue - smoke duct in a chimney, or a proprietary
pipe serving a heat producing appliance such as a central heating boiler.
Flue Lining - metal (usually stainless steel) tube
within a flue. Essential for high output gas appliances such as boilers. May
also be manufactured from clay and built into the flue. Other proprietary
flue liners are also available.
Footings - older, usually shallow, form or
foundation of brick or stone.
Foundations - normally concrete, laid underground
as a structural base to a wall; in older buildings these may be brick or
stone.
French Drain - a gravel filled drainage trench,
typically constructed against a wall. Can be a cost effective way of
reducing damp caused by high ground levels without the need for extensive
removal of paths/hardstanding.
Frieze - The area of an internal wall above the
picture rail.
Frog - an indention, usually V shaped in the
bedding face of the brick to reduce its weight. "Frog down " or "Frog up"
are the generally accepted ways of describing how the brick are laid.
Gable - upper section of a wall, usually triangular
in shape, at either end of a ridged roof.
Ground Heave - swelling of clay sub-soil due to the
presence of moisture: can cause an upward movement of floors or foundations
in extreme cases.
Gulley - an opening into which rain and waste water
are collected before entering the drain.
Gutter - a channel along the eaves of a roof or the
edge of a path for the removal of rainwater.
Hardcore - broken bricks or stone which,
consolidated, are used as a base under floors.
Haunching - see "Benching". Also term used to
describe the support to a drain underground. Head - upper horizontal member
of a door frame, window frame, partition frame etc.
Hip - the junction between the slopes at the angled
end of a roof.
Hip Tile - a saddle shaped or angular tile fitting
over the junction of the roof slopes at a hip.
Hopper - enlarged top usually to a vertical down
pipe to receives water from rainwater or waste pipes.
In Situ - "In position" - applied to work done in
the position where it is finally required, e.g. concrete may be pre-cast in
sections which are later taken to the position where they are required or it
may be cast 'in situ'.
Inspection Chamber - commonly called the
"man-hole": access point to a drain comprising a chamber (of brick, concrete
or plastic) with the drainage channel at its base and a removable cover at
ground level.
Interstitial Condensation - condensation which
occurs within the thickness of a material, rather than on its surface.
Jamb - vertical side face of a doorway or window.
Joist - a timber or steel beam directly supporting
a floor and sometimes alternatively or additionally supporting a ceiling.
Steel beams are usually referred to as RSJs (rolled steel joists).
Kerb - profile fixed to a flat roof deck abutting
an adjacent wall, but not fixed to it. Usually of shaped timber
construction.
Key - the roughness of a surface, which provides
a bond for any application of paint, plaster, rendering, tiles etc, or
spaces between laths or wire meshes which provide a grip for plaster.
Landslip - downhill movement of unstable earth,
clay, rock etc often following prolonged heavy rain or coastal erosion, but
sometimes due to sub-soil having poor cohesion.
Lath - any base for plasterwork; typically thin
wooden strips in older property. Now mainly expanded metal.
Lintel - a horizontal beam over a door or window
opening usually carrying the load of the wall above. Often lintels can be
partially or completely hidden from view.
Load-Bearing - usually applied to walls or other
structures which carry loadings from walls, floors or roof at higher level.
Longhorn Beetle - (Hylotrupe bajulus). A serious
insect pest mainly confined to the south-east of England, which can totally
destroy the structural strength of wood.
Long Straw - method of thatching with straw.
Only has a short life.
LPG - liquid Petroleum Gas or Propane. Available
to serve gas appliances in areas without mains gas. Requires a correctly
positioned storage tank or bottles. Can be relatively expensive.
Macerator - an electrical device attached to a WC
that shreds and pumps away the waste. This enables the use of small diameter
waste pipes and enables the fitting of a WC in locations away from soil
pipes or in basements.
Mansard Roof - pitched roof which has, on each
side, a shallower upper slope and a steeper lower slope.
Mortar - mixture of sand, cement, water and
sometimes lime used to join stones, blocks or bricks.
Mortice Lock - lock set within the door thickness.
Mastic - a permanently flexible waterproofing
material mostly used for sealing external or water-vulnerable joints in
building or glazing etc.
Mullion - vertical bar dividing individual lights
in a window.
Newel - stout post supporting a staircase handrail
at top and bottom. Also, the central pillar of a winding spiral staircase.
Open Valley - valley gutter in which the adjoining
slates or tiles are so cut that the metal sheet or other waterproof material
lining the valley, is exposed. Open valley gutters are less prone to
blockages than cut valleys.
Oversite - rough concrete below timber ground
floors.
Padstone - Hard brick or concrete used to spread a
point load on a wall - often below a beam.
Parapet - low wall along the edge of a roof,
balcony etc.
Parapet Gutter - a gutter usually provided with a
flexible metal or other impervious lining. Used behind a parapet or
sometimes at a valley. Frequently hidden and often a source of damp.
Partition - wall between rooms usually non-load
bearing.
Pier - a vertical column of brickwork or other
material, used to strengthen the wall or to support a weight.
Plasterboard - sandwich of plaster between paper.
Commonly used for ceilings and partition walls.
Plywood - board made from veneers of wood glued
with the grain laid at right angles.
Pointing - outer edge of mortar joint between
bricks, stones etc.
Powder Post Beetle - (Bostrychide or Lyctidae family of
beetles). A relatively uncommon pest that can, if untreated, cause
widespread damage to structural timbers.
Purlin - horizontal beam in a roof upon which
rafters rest.
Quoin - the external angle of a building; or
specifically, bricks or stone blocks forming that angle.
Radon Gas - colourless and odourless gas
prevalent in some areas. Linked to cancer.
Rafter - a sloping roof beam, usually timber,
forming the carcass of a roof.
Random Rubble - basic early method of stone wall
construction with no attempt at bonding or coursing.
Rendering - cement or lime covering of a wall
either internally or externally, sometimes with pebbledash, stucco or
Tyrolean textured finish.
Reveals - the side faces of a window or door
opening.
Ridge - the highest part or apex of a roof.
Ridge Tile - a specially shaped tile for covering
and making weather tight the ridge of a roof. These tiles may have a rounded
or angular cross-section.
Riser - the vertical part of a step or stair.
Rising Damp - moisture soaking up a wall from
below ground, by capillary action which can cause rot in timbers, plaster
decay, decoration failure etc.
Roof Deck - usually timber or ply boarding to a
flat roof below the waterproof layer.
Roof Spread - outward bowing of a wall caused by
the thrust of a badly restrained roof framework (see (collar").
Roof Void - unused space between the roof and the
ceiling of the highest storey (often called the loft or attic).
RSJ - frequently used abbreviation for a Rolled
Steel Joist.
Sarking Felt - felt or other lining laid across
rafters of a pitched roof to provide a secondary means of defence against
water penetration.
Screed - final, smooth finish of a solid floor;
usually cement, concrete or asphalt.
Scrim - coarse mesh used for bridging the joint
between plasterboard sheets to prevent cracking. Used to be cotton or
canvas, now mainly plastic.
Secondary Glazing - additional layer of glazing
fixed in its own frame within a window opening. Often preferred in older or
listed buildings where it is important to preserve the existing frames.
Septic Tank - private drain installation whereby
sewage decomposes through the action of bacteria, which can be slowed down
or stopped altogether by the over use of chemicals such as bleach,
biological washing powders etc.
Settlement - downward movement of a structure due
to its own weight rather than due to another factor, such as a tree or
defective drain etc. All properties settle to some extent, and this can show
as cracking and/or distortion in walls. Very often minor settlement is not
of great significance to the building as a whole.
Sewer - a large, underground pipe or drain used for
conveying waste water and sewage. The Local Authority is usually responsible
for the sewers, which collect the effluent from various drains, the drains
being the responsibility of the land owners.
Shakes - naturally occurring cracks in timber; in
building timbers, shakes can appear quite dramatic, but strength is not
always impaired.
Shiplap - horizontal external boarding, usually
timber or PVC-u.
Shingles - small rectangular slabs of wood used on
roofs instead of tiles, slates etc. Sometimes also used to face walls.
Skylight - a window set into a roof.
Soakaway - a pit, filled with broken stones etc
below ground to take drainage from rainwater pipes or land drains and allow
it to disperse.
Soaker - piece of flexible metal fitted to
interlock with slates or tiles and make a watertight joint between a wall
and a roof or at a hip or valley. Stepped flashings are used over the
soakers at a joint against a wall.
Soffit - the underside of an arch, beam, staircase,
eaves or other feature of a building.
Soil Pipe/Soil Stack - a vertical pipe conveys
sewage to the drains. Its upper end it usually vented above the eaves.
Solid Fuel - heating fuel, normally wood, coal or
one of a variety of proprietary fuels.
Soldier Arch - flat arch of uncut bricks on end,
usually over a window opening.
Spall - splitting of masonry, tiles etc. Usually
due to the freezing and expansion of trapped water (frost damage).
Spandrel - panelling above and to the sides of an
arch; also the space below a staircase.
Spindle - a balluster. Often a decorative series of
timbers infilling between the bannister and stairs.
Stopcock - a valve on a gas or water supply pipe
which is used to cut off the supply.
String - the sides of a staircase. The one fixed to
the wall is the 'wall string'; the other is the 'outer string'.
Stud Partition - lightweight, sometimes non-load
bearing wall construction, comprising a framework of timber faced with
plaster, plasterboard or other finish.
Strut - a support, usually a roof timber.
Subsidence - ground movement, generally
downward, due to failure or shrinkage of the subsoil. Often caused by trees,
drains etc.
Sub-Soil - soil lying immediately below the
topsoil.
Sulphate Attack - chemical reaction, activated by
water, between tricalcium aluminate and soluble sulphates which can cause
deterioration in brick walls and concrete floors.
Surface Water - another term for rainwater.
Tell-tale - a measure fixed across a crack to
monitor movement. Strips of glass used to be fitted to check for movement
and can occasionally be seen on older buildings.
Tie Bar - metal bar passing through a wall, or
walls, bracing the structure. often used to correct bulging walls.
Torching - traditional method of waterproofing by
applying mortar to the underside of roof tiles or slates. Rarely effective,
and now not used as modern roofs are usually lined.
Transom - horizontal bar of wood or stone across a
window or top of door.
Trap - a 'U' shaped bend in a waste pipe, soil pipe
or gulley containing enough water to provide a seal and prevent the ingress
of foul air into a building.
Tread - horizontal part of a step or stair.
Trussed Rafters - (or pre-formed trusses) method
of roof construction utilising prefabricated triangular framework of
timbers. Now widely used in domestic construction.
Underpinning - method of strengthening weak
foundations whereby a new, stronger foundation is placed beneath the
original. Underpinned properties can be difficult to sell and insure.
Valley Gutter - horizontal or sloping gutter,
usually lead-or-tile-lined, at the internal intersection between two roof
slopes.
Verge - the edge of a sloping roof which overhangs
the gable. Verges are often finished with mortar and a barge board below.
Ventilation - necessary in all buildings to
disperse moisture resulting from bathing, cooking, breathing etc, and to
assist in prevention of condensation. Particularly important with timber
ground floors to reduce the rate of decay to the timbers.
Wall Plate - horizontal timber in or at the top of
a wall supporting floor joists, ceiling joists or rafters.
Warm Roof - a roof where the insulation is placed
between the roof deck or structure and the covering.
Waste Pipe - a pipe usually carrying water away
from a basin, bath or sink.
Water Bar - small metal bar rising above the level
of threshold to a door to prevent water blowing below it.
Water Reed - very durable thatching material. Used
to be sourced principally in Norfolk and is often called Norfolk reed.
Weather Strip - moulding fitted at the base of an
external door to throw water clear from the threshold below.