Help with those Trade and DIY terms

Here’s our list of regularly used Trade and DIY terms.


A

Acid

Technically substance that can donate a hydrogen ion (H+) to another substance. Acids have a pH less than 7.0. Example products containing acid include hydrochloric acid industrial brick and patio cleaners for removing dirt, algae and moss on paved areas, walls, concrete surfaces, brickwork and patios. Products containing strong amounts of acid should be used by trained technicians only.

Aggregate

Material such as sand or gravel used with cement and water to make concrete, mortar, plaster or tarmac repair.

Algae

Algae is an informal term for a large group of photosynthetic eukaryotic organisms. Usually found on roofs, walls, patios and external damp areas.

Amp

Ampere, the unit for the measurement of electric current.

Antibacterial

Anything that destroys bacteria or suppresses their growth or their ability to reproduce.

Asphalt

Tar-like substance used as a binder for aggregates such as gravel or sand and commonly used for roads, paving and flat roofs.


B

Basement

The floor of a building which is partly or entirely below ground level.

BBA

British Board of Agrément. The BBA are in charge of the Agrément Certificate product approval work.

Beading

A sealant product or moulding used to decorate or conceal joints.

Biodegradable

Something which is able to decay naturally and in a way that is not harmful to the environment.

Bitumen

Black, sticky substance similar to asphalt, used in mineral felts, sealants and damp-proof courses.

Bituminous

A substance of, containing, or of the nature of bitumen.

Bleach

Generic name for any chemical product which is used industrially and domestically to clean, and to remove stains. Commonly refers to a dilute solution of sodium hypochlorite known as ‘liquid bleach’.

BS 8102:2009

2009 Code of Practice for Protection of Structures Against Water from the Ground is a design document whose purpose is to inform the designer of the various methods of waterproofing available and to assist in the correct specification of those systems.

Butyl rubber

A flexible material available in sheets used for flat roof coverings and pond liners.


C

Caulk

A flexible compound used to seal cracks and fill holes on a variety of surfaces.

Cavity wall insulation

Filling of wall cavities by one of various forms of insulation material, such as polystyrene beads, foam or fibreglass.

Cellar

A room below ground level in a house that is often used for storing wine, coal or other specific purpose. A cellar is often smaller than a basement.

Cement

Dry powder adhesive used to bind ingredients together when making concrete.

Cementitious

Refers to the nature of cement products which comprise of a glue that holds the concrete together.

Cobblestone

A round stone for paving. Often shortened to cobble.

Coping Stone

A stone that forms the top of wall or building.

CSS

County Surveyors’ Society.


D

Damp-proof course DPC

Layer of damp-proof material between the courses of bricks near the bottom of exterior walls often referred to as DPC.

Dry lining

Plasterboarding walls and ceilings by fixing sheets of pre-plastered boards to a timber frame or metal channels.

Dry rot

The damage caused to timber and other materials by a fungal attack.

Dubbing out

Filling larger voids in an uneven surface before plastering or rendering, often using brick or tile to avoid extra thickness.


E

Eco-friendly

Not harmful to the environment.

Efflorescence

Found as a sign of rising damp and refers to the migration of a salt to the surface of a porous wall, where it forms a coating. Taken from the French ‘to flower out’.

Expansion joint

The narrow gap filled with treated fibreboard between bays of concrete to allow for expansion and contraction.


F

Fascia

A flat surface, usually made of wood, that covers the end of roof rafters and on which the guttering is fixed.

Flaking (see also Spalling)

Surface flaking in natural stone is an indicator of sub-florescence where mineral salts are carried into the stone by moisture and accumulate beneath the stone’s surface, creating stress within the pores of the stone. This is particularly damaging for external stone exposed to frost.

Flashing

Waterproof material used to seal exterior joints such as between the roof and walls or chimney; or where two roof planes meet.


G

Grout

A compound used to fill the gaps between ceramic tiles.


H

Hardwood

Timber generally from deciduous trees, used in construction e.g. oak, ash, beach and birch.

HPAS

Highways Authorities Product Approval Scheme


I

Insulation

Any material used to prevent or limit the passage of heat or sound. Also a non-conductive material surrounding electrical wires or cores.


J

Joist

Timber or steel beams for supporting floors and ceilings.


K

Keying

The process of creating a rough surface to provide a better grip for plaster, paint or adhesive.


L

Lagging

The insulation material used to wrap around pipes and tanks in unheated areas to prevent freezing. Also, used on hot water tanks to prevent heat loss.


M

Mastic

A sealant used to waterproof joints with a flexible, rubbery consistency even when dry.

Membrane

In waterproofing a membrane is a layer of water-tight material applied to a surface in order to waterproof it.

Mist Coat

A coat made of watered down paint and applied in as thin layer on new plaster on walls to seal it and prevent peeling.

Mortar

A mixture of sand, cement and water used in bricklaying and rendering.

Mould

A fungus that grows in the form of multicellular filaments called hyphae. Often found in damp building materials with a like stain-like appearance. A musty smell is an early sign of mould and if unchecked leads to poor indoor air quality. Dry Rot is a highly destructive mould.


N

Newel

An upright post fixed at the foot of a stair or at a point of a change of direction and used as a support for a balustrade.


O

Olive

A metal ring used in plumbing to create a seal for brass compression joints.


P

Paviour

Material used for paving, the person who lays it or the machine used to ram down pavement.

Polyurethane

Polyurethane (PUR and PU) is a polymer composed of organic units joined by carbamate (urethane) links. Used in Polyurethane Liquid Membrane for waterproofing.

PVA

Is the abbreviation for Polyvinyl acetate which is a synthetic resin that can be used as an adhesive or, when diluted with water, a sealer on porous surfaces.

PVC

PVC (Polyvinyl chloride) is a thermoplastic material used extensively in the construction industry. Uses include insulation for electric wire, roofing sheets, and soft floor tiles. PVC is also used in rigid form to manufacture guttering, drain pipes and window frames.


Q

Quarry Tiles

A square or diamond-shaped unglazed floor tile.


R

RAL

RAL is a colour matching system used in Europe.

Rising damp

A serious damp problem caused by moisture from the ground rising through the walls or floor of the house.

RSJ

Abbreviation for Rolled Steel Joist.


S

Screed

A thin layer of mortar applied to the surface of a concrete floor to give it a smooth finish.

Sealant

A flexible, waterproof substance used for sealing along joints. Normally applied using a cartridge applicator.

Sett

A small rectangular paving block made of stone, such as granite, used to provide a durable path, patio or driveway.

Slurry

A mixture of denser than water solids suspended in water or other liquid. Used in cementitious waterproofing.

Spall (see also Flaking)

The result of water entering brick, concrete, stone, plaster etc. resulting in the surface peeling or flaking off. Also known as flaking, especially in limestone.

Square Metres or Feet

Area is measured in ‘square’ units with the area of a square = side x side. Coverage is often quoted in square metres m² or square feet ft²

Substrate

An underlying layer or substance.


T

Tanking

To create a tank-like seal with waterproof material to protect walls and floors against water penetration, particularly in basements and cellars.

Tarmac

A paving material that consists of crushed stone rolled and bound with a mixture of tar and bitumen. Used for a roads, paths, patios, motorways, airport runways etc. Short for Tarmacadam.

Topcoat

The finishing coat applied to an undercoat or first coat, usually in reference to paint or plaster.


U

Undercoat

The foundation coats applied before the topcoat.

UPVC

UPVC (unplasticised polyvinyl chloride) is a rigid plastic material widely used in the construction industry in the form of pipes, guttering, window and doorframes, fascias and soffits.


V

Vermiculite

A granular material with thermal insulating properties which is used as loose-fill loft insulation. It can also be mixed with cement to form a lightweight, fire-resistant concrete.


W

Weatherboard

The cladding or ‘siding’ of a house consisting of long thin timber boards that overlap one another, either vertically or horizontally on the outside of the wall.


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Z