The use of materials such as glasspaper, wet-or-dry paper, sanding discs, etc. to smooth down a surface prior to painting, or to matt down existing coatings to provide a 'key' for subsequent coats of paint.


The degree to which a surface can soak up a liquid. Some surfaces have varying absorbency, for instance, softwoods vary in grain pattern. One of the requirements of a primer is to produce a non-absorbent surface.

Accelerated weathering

Laboratory or field tests intended to simulate natural outdoor weathering in an intensified or accelerated degree. There is no generally accepted type of laboratory test and expert opinion does not accept that such artificial tests give a true reflection of natural behaviour.


A waterborne latex used in emulsion paint and universally accepted. A synthetic polymer used in high performance latex or water-based paints as the paint's binder acrylic resins enable the coating to last longer and retain its colour.

Acrylic emulsions

These are prepared from acrylic derivatives and normally show very good toughness and adhesion even under wet conditions as well as very good alkali resistance.


The degree of attachment of a paint coating to a surface. Weak adhesion of paint to a surface is a common cause of paint failure. The quality or degree of attachment between a paint coating and the surface or paint beneath it. The ability of dry paint to remain on the surface without blistering, flaking or cracking. Adhesion is probably the single most important property of paint.


A collection of minerals, i.e. fine particles of stone, grit, mica, etc. which provide the textured finish of materials, such as Weather-coat No.1.


A description used for paints that dry solely or mainly during exposure to air at normal temperatures, as distinct from those that require heat-treatment (stoving and force-dried paints) or those that set independently of the surrounding atmosphere (catalysed or "accelerated" paints).


The side portions of a church parallel to the knave. Any passage way divided off by pillars.


A recess or niche; sometimes flanked by columns.

Alkali resisting primer

A paint used as a barrier to alkaline substances in the surface which would otherwise attack the paint film. Alkaline surfaces which are continually damp are not effectively sealed for long periods by this method.


A type of "synthetic" resin that is built up from relatively simple non-resinous components. In practice an alkyd varnish is made by adding such components to a drying oil and treating to produce an "oil-modified alkyd varnish". This process is distinct from the traditional method in which a separate gum or resin is "cooked" with a drying oil to produce a varnish.

Angle iron

Used to describe any cast or rolled steel strip of L section.


A method of treating aluminium or light alloy to provide a non-corroding oxide film on the surface of the metal.


A general term for paints used to prevent the corrosion of metal, especially of iron and steel.


Compositions used to prevent the growth of barnacles, arine weed and other organisms on ships' bottoms.


A carpentry term which describes the moulding surrounding a door or window opening.


The sharp edge formed by the intersection of two surfaces. This term is commonly used to refer to the edges in a moulding.

Asbestos cement

Usually refers to a type of asbestos sheet, or to casting where the asbestos is bonded together with Portland cement, e.g. asbestos, cement sheet, tiles, rain-water pipes, etc.


Stones which have been cut square are called ashlar as opposed to rough stoned which have been quarried.

Adhesion failure on metal

Adhesion failure on metal substrates, resulting in blistering, flaking/delamination and corrosion, is usually due either to surface contamination or poor surface preparation.
Among the most common types of surface contamination are grease on new galvanised surfaces, which should be cleaned with Dulux Oil and Grease Remover; and wax residue resulting from the use of chemical paint strippers, which can be removed with Dulux Oil and Grease Remover. Dust and general debris should always be vacuumed away before painting.
In terms of surface preparation, the failure to remove millscale from hot rolled mild steel prior to painting can lead to serious problems months or even years later. Similarly, painting over rust can result in the paint film flaking or the rust breaking through the paint film.



The layer of putty which is put first in the sash bar before inserting the glass.


A column in a balustrade used to describe the posts supporting a handrail. See also 'banister'.


The posts supporting a handrail on a staircase. If turned in the form of ornamental columns they are more correctly termed 'balusters'.

Barge board

The board at the top of a gable where the wall meets the rough edge. Also called a parge board.

The bottom of a wall or column.


A strip of wood, usually pine or fir, and between two and nine inches wide but less than nine inches.


Any part of a building cut off by timbers, buttresses, beams, etc. Especially used for sections of roof or floor between beams or arches.


Correctly refers to any small moulding in the form of beads on a string but is commonly used to describe small mouldings of other designs.


Any horizontal structure usually supported at each end. The term is therefore used to describe horizontal projection, whether load-bearing or not.


The horizontal surface of a stone. Also used to describe the large flat areas of a ceiling between beams.


Building Information Modelling (BIM) is used in building design and integrates 3D models with rich information. BIM objects combine performance, scheduling, fire rating, and many other parameters, with physical geometric attributes, in digital form.


The binder cements the pigment particles into a uniform paint film and makes the paint adhere to the surface. The nature and amount of binder determine most of the paint's performance properties such as washability, toughness, adhesion and colour retention.


A description applied to paint coatings that exhibit bits of skin or other extraneous matter.

Bituminous paint

Dark-coloured paints or coatings based on natural bitumens dissolved in organic solvents. They can include paints containing petroleum asphalt but are not generally used to those based completely upon coal-tar.


A method of pressure cleaning used to remove rust, millscale or paint coatings in poor condition using grit or water under pressure.


Loss of colour usually caused by exposure to sunlight.


Soluble matter leeching out from a substrate or previous coating, causing discolouration of fresh paint, e.g. bitumen bleed or nicotine staining.


A 'swelling' of the paint film into the form of blisters often caused by resinous exudation from timber or moisture in the substrate.


A greyish milky-coloured 'haze' appearing on the surface of the paint film usually caused by moisture attack during drying.


The apparent viscosity of a paint, especially in relation to its appearance and behaviour in the container and during application. A high-viscosity paint may be termed 'full-bodied'. It can also be used to describe the 'build', or coat-thickness, of an applied coat.


The system whereby stones or bricks are laid in over-lapped courses so that vertical joints in one course do not coincide with those in the next.

Bottom rail

The lowest horizontal member of a framed door.

Box gutter

Usually a wooden gutter lined with sheet-lead, zinc or asphalt used in roof valleys or parapets.


A building block made from cement and ashes or coke which is used mainly for internal walls.


Where a paint film appears to be in continuous contact with a surface but is in reality not in contact at some points, i.e. by spanning or bridging over open cracks with a thick coat of paint.

Bringing forward

This term is used to describe the preparation and spot priming or other painting which is required to bring repaired or bare surfaces to match the adjacent paintwork so that subsequent painting results in even appearance.

Broken colour

A multi-coloured effect obtained usually by the merging of wet paints of different colours during application.

Bronze paint

Descriptive of metallic paints composed of copper-bronze or tinted aluminium powder in a clear medium. So-called gold paints are in fact of this type and the term bronze or gold-bronze is used to describe the whole range, irrespective of colour.


A metallic lustre or iridescent 'bloom' that may develop on full-coloured paints based on certain pigments, e.g. Prussian and phthalocyanine blues.

Brunswick black

A black varnish, usually a solution of asphalturn.

Brunswick green

A green obtained from a mixture of Chrome yellow and Prussian Blue.


The actual or apparent thickness of a dried film of paint.

Burning off

The removal of paint by means of heat applied to the surface by means of a blow-lamp.


A joint formed between two squared ends which come together but do not overlap. Also used for 'butt hinge' and refers to the type of hinge commonly used for doors and casements.

Blistering of paint on plaster

Blistering can occur on plaster if you overcoat solvent-based paints such as gloss or eggshell with a conventional emulsion in an area that suffers from high levels of condensation.
To resolve the problem, scrape back the blistered paint until you have a firm edge, feather lightly with abrasive paper and dust off. Now spot, prime and bring forward any bare areas with Dulux Primer Sealer, using Dulux Alkali Resisting Primer on friable surfaces. Finally, repaint the surface using a thinned first coat of water-based Dulux Trade Quick Drying Eggshell followed by one or two full coats.


Common causes of bleeding from the surface below include old wallcoverings, bituminous paint and creosoted surfaces, so these should be completely removed before painting. If this is not possible apply one or, in severe cases, two coats of Dulux Aluminium Wood Primer. New creosote or bituminous materials must be aged for at least 12 months before painting. For staining by metallic inks in wallcoverings or felt tip pens, the surface should be touched in locally with Dulux Alkali Resisting Primer.


This greyish, milky-coloured ‘haze’ on the surface of the paint film is usually caused by moisture attack during drying. Thoroughly clean down the surface to remove all dirt, grease and surface contaminants, then rub down with a suitable abrasive and dust off prior to re-applying paint.


Full coloured paints based on certain pigments, such as Prussian and phthalocyanine blues, can produce a metallic lustre. To cure this irridescent effect, thoroughly clean down the surface to remove all dirt, grease and surface contaminants, then rub down with a suitable abrasive and dust off before repainting.

Brush disturbance/floating/flooding

When pigments have been disturbed in this way, wait until the paint is completely dry. Thoroughly clean down the surface to remove all dirt, grease and surface contaminants, rub down with a suitable abrasive and dust off, then reapply paint.


There's only one way to cure this problem. Thoroughly clean down the surface to remove all dirt, grease and surface contaminants. Then carefully scrape back any areas of poorly adhering or bubbled coating to a firm edge. Rub down to 'feather' any broken edges, dust off, and reapply paint



Cast Iron; an abbreviation widely used in building.


The top of any work but especially short term for capital.


The ornamental mouldings at the top of a column pier or pilaster.


A window hinged to open along one of its vertical edges.

Cavity wall

Hollow wall, normally consisting of two 4.5 inch brick walls with a 2-inch cavity between, being tied together at intervals with metal ties. It provides better thermal and moisture insulation than the equivalent solid wall of 9†brickwork.

Cellulose paint

Paint in which the binder consists essentially of nitrocellulose or cellulose acetate dissolved in suitable solvent.


A temporary timber support for an arch during its construction.


The disintegration of paint film into a faded powdery substance. Chalking occurs when the binder cannot withstand harsh environmental conditions. Re-painting over a chalky surface is difficult unless a paint has the high adhesion provided by acrylic binders.


An arris edge or angle that has been slightly pared off or bevelled.


A form of 'cracking' q.v.


The character of a paint film which, although dry, is still soft and mechanically weak.


A patterned steel plate used for flooring.

Chimney breast

The projection formed in a room by the flue and fireplace.


A building board or sheet made from wood chips bonded with resin or plastic.


The failure of a paint film whereby the film chips away from the under surface, e.g. paint applied over varnish will chip if knocked leaving the varnish on the surface.

Chlorinated rubber

Superceded in many cases by Acrylated rubber due to the trichloromethane. Natural rubber re-acted with chlorine to produce a hard resin-like substance which forms the basis of binder for a range of specialised paints.


The failure of paint to form a continuous film by forming into ‘droplets’. Usually caused by grease or other contamination on the surface being painted.


Reservoir for storing water, nowadays usually ceramic or plastic.


The term used to describe the surface covering of a building particularly in sheeting or boarding.


A mixture of glue-size and whiting used as a primer or undercoat beneath size-bound distemper. Also spelt clairolle and clearcolle.

Coarse stuff

The first coating in plaster work particularly on lathing or rough brickwork.


Term used generally to describe a single application of any type of paint or varnish.

Colour retention

The ability of paint to keep its original colour and resist fading.


A pigment dispersed in a medium which is used for tinting a paint after manufacture.


Long vertical cylinder or shaft supporting a roof beam or entablature, or alone as a monument.

Commercial match

Although paints are matched to a standard there is always some ‘tolerance’ between batches. It is possible therefore that there may be a variation in shade between different batches although each batch is a good ‘commercial match’ to standard.


Paints which can be mixed together without adversely affecting any of their properties, or the application of one type of paint over a different type without either being adversely affected.

Complementary colours

Contrasting or opposite colours which accentuate one another when placed side by side.


A mixture of cement, sand, gravel and water.


A pipe or channel for conveying water; a trough or pipe for containing wires or cables.


A term used to describe the thickness of a paint in the can. While paints of thick consistency are usually expected to be difficult to spread, this will not be the case with 'Gel' and 'Thixotropic' paints. Paints can usually be brought to a thinner consistency by thinning.


The resistance of a paint to flow. A paint with high consistency flows slowly: with low consistency it flows readily.

Cool colours

Any of the hues in which blue predominates. Opposite to 'warm colours'.


A group of natural resins which were formerly used in the manufacture of varnish but which have now been superceded by synthetic resins.


The product obtained when two or more compounds are chemically reacted with each other (co-polymerised) to produce a resinous type material. Copolymers form the basis of many types of paint and plastics.


A piece of brick, stone or metal projecting from a wall to support a load or a bracket.


A projecting moulding decorating the top of a building or wall, e.g. the moulding between wall and ceiling.


A destructive attack of metal caused by oxidation, e.g., rust on ferrous metals or white deposit forming on aluminium. Corrosion destroys the surface of metal and this process is accelerated in chemical or salt laden atmospheres.


A horizontal layer of bricks or stones in a wall.


Any kind of concave moulding usually large.

Cover fillit

Any beading small moulding or strip used to cover a joint.

Covering power

This term should not be used as it can be confused between the two qualities of hiding-power or opacity and of spreading power or area covered by a given amount of paint. ‘opacity’ and ‘spreading capacity’ are better terms to use.


Fine lines or cracks usually occurring when a hard drying material is applied over a soft material e.g. gloss paints applied over bituminous coatings.

Crackle finish

The application of a top coating designed to ‘shrink’ and crack exposing a different colour underneath.


Similar to 'cracking' but usually referring to overall haphazard cracking rather than continuous or straight splitting. 'Checking' is a similar defect but in smaller scale.


The chemical process by which paints dry. Most commonly used when referring to the chemical reaction by which two-pack products dry e.g. two-pack epoxies two-pack polyurethane.


See 'sagging'


A paint film that has dried in this condition is mechanically weak and needs to be completely removed. Carefully clean down the surfaces and allow to dry before reapplying paint.


Paint applied over varnish or wood stain can sometimes chip off if knocked. Should this happen, you'll first need to thoroughly clean down the surfaces to remove all dirt, grease and surface contaminants. Then carefully scrape back poorly adhering or defective paint to a firm edge and rub down to 'feather' broken edges. If chipping is severe, the surface will need to be totally stripped back. Dust off prior to replying paint.

Cissing on new paintwork

The paint can't adhere to the surface because of contamination by oil, grease, wax or polish. So the paint draws back, leaving unpainted areas, usually in the form of small spots. To remedy the situation, allow the surface to dry and thoroughly harden, then rub it down using wet and dry abrasive paper (or waterproof silicon carbide) and warm water with a bit of detergent. Rinse the surface thoroughly and allow to dry before repainting.

Colour change (fillers)

Fillers are absorbent and have a different porosity than the substrate, which can cause variations in colour. Therefore, fillers should be applied as early as possible in the process to avoid variations in gloss, sheen or colour. Before repainting, thoroughly clean down the surfaces to remove all dirt, grease and surface contaminants, then rub down with a suitable abrasive and dust off the whole surface. Prime with one coat Dulux Alkali Resisting Primer thinned with up to one part Dulux Thinner 41 or white spirit to 10 parts paint.

Cracking of plaster

It is quite normal for small cracks to appear in plaster on interior walls and ceilings, either through drying out in new homes or movement of the building in older homes. Simply cut out the cracks, dust off and fill with a suitable interior filler. Allow to dry, then rub down smooth and dust off to create a clean, smooth surface for decorating.

Cracking on outside paintwork

This cracking develops as the paint begins to lose flexibility and it no longer expands and contracts with the substrate. The more layers of paint, the worse the problem. Small areas of cracking can be treated by scraping and rubbing down. But large areas will need to be completely removed with a hot air gun or suitable chemical paint remover. Bare surfaces should be primed with an appropriate Dulux Primer before painting.



The plain face of the body of a pedestal hence the deep border or band around the lower part of a room wall.

Damp course

A layer of slate lead or bituminous composition built into a wall to prevent damp rising from the ground or soaking in from a ledge or parapet.


Any change from the original colour can be caused by a variety of factors e.g. atmospheric pollution ageing of oil based paints.


The way pigment particles are distributed finely and evenly throughout the paint medium.


The suspension of very fine particles of solid pigment in oil varnish or other medium.


A term used for the broad classification of water thinned coatings which were generally used for walls and ceilings before the advent of modern emulsion paints.

Door furniture

Term covering the fittings to a door viz. Handles finger-plates etc.


The solidification of an applied paint film. Emulsions dry by evaporation of water oil based paints dry by evaporation of solvent followed by oxidation of the oil content.

Drying time

The time required for an applied paint film to reach its full degree of hardness.


The degree to which paint withstands the destructive effects on the environment to which it is exposed especially harsh weather conditions. Durability has two aspects. Its protective properties safeguard the substrate from degradation. Its decorative properties allow the paint to retain its attractive appearance.

Dutch metal

A cheaper alternative to gold leaf consisting basically of copper.

Dampness in walls

Dampness can be caused by any number of problems, from broken rainwater pipes to defective pointing in brickwork. Whatever the source, it needs to be identified and cured. Before painting, the surface must be completely dry. If a water stain remains on a dry surface that is to be painted, first touch in locally with Dulux Alkali Resisting Primer. Areas that are to remain unpainted, such as brick or stonework, can be protected with Dulux Weathershield Waterseal.

Denatured (grey) wood

No. Failing to completely remove wood that has been exposed to weather and sunlight is a common cause of paint failure. Use a sander to remove the top surface layer of the grey wood, making sure that the surface is cleaned back to new sound wood. Prime all bare wood with Dulux Primer or Basecoat before re-painting.

Dust/bittiness on new paintwork

This can be caused by dust and dirt in the air settling on the paint surface; by using a dirty paint brush, or by stirring skin into the paint. In either case, let the paint dry and harden, then rub down using wet and dry abrasive paper and warm water with a bit of detergent. Rinse thoroughly with clean water and allow to dry before repainting. Use only good quality paint brushes and wash out with a little white spirit, making sure the brush is completely dry before starting work. Avoid stirring skin into the paint by straining into a clean kettle before use.



Known as 'efflorescence', these effects appear as a result of salts crystallising in materials such as bricks. The fluffy deposits can be removed with coarse Hessian sacking or by dry brushing, repeated every few days until the deposits disappear. Hard, shiny efflorescence can be sanded to roughen the surface, then painted over. Conventional solvent-based paints should not be applied on new buildings where efflorescence occurs for at least 12 months, to allow the surface time to dry out thoroughly. Use Dulux Alkali Resisting Primer prior to applying any solvent-based finishes. Alternatively, specify a Dulux Quick Drying water-based paint.

Earth pigments

A class of pigments usually mined direct from the earth. Also known as natural or mineral pigments e.g. red and yellow iron oxides yellow ochre, raw sienna, raw umber.


The lower edge of a roof where it projects beyond the face of a wall.


These salts originate from the bricks concrete blocks concrete etc. and brought to the surface by water drying out. These salts will go through plaster but will not normally originate from modern type plasters. Generally efflorescence is likely to persist until such time as the substrate has fully dried out. Active efflorescence is likely to push off any type of sealer or paint coating.


A degree of glossiness broadly midway between matt and high gloss.


The ability of paint to expand and contract with the substrate without suffering damage or changes in it's appearance. Expansion and contraction are usually caused by some temperature fluctuations. Some substrates such as yellow pine expand at different rates depending on the type of their grain. Elasticity is a key to durability.


The facade of a building; the external elevation.

Emulsion paints

Water thinned paints based on a variety of synthetic resins including acrylics vinyl acetate and vinyl versatate. These generally have fair to good resistance to alkali and are permeable to water vapour which enables them to be used for early decoration by direct application to new plaster cement rendering and similar surfaces.


Traditionally a slow-drying highly glossy paint having very good flowing properties but low opacity. Recently has been used more widely to describe any type of high-gloss finish.


Ornament particularly carved or modelled decoration to a building.


What is an EPD? An environmental product declaration (EPD) is a document that transparently communicates the environmental impacts of a product across its lifecycle. Like material safety data sheets EPD's describe a product's attributes in a consistent and comparable way.

Epoxy resins

Synthetic resins which when used in a two-pack product have good resistance to chemicals hard wear and abrasion.

Etch primer

A thin lightly pigmented primer designed to increase the adhesion of a paint process when applied to surfaces particularly of non-ferrous metal on which paint will not normally adhere well. Also called wash primer.


A less expensive ingredient than pigment (titanium dioxide) it fills out and extends the pigment's capabilities. Extender cannot be used without pigment. Some common extenders are clays calcium carbonates and silicas.


  • Tapering off the edges of a coat of paint when touching in by laying off with a comparatively dry brush.

  • Where some paint has flaked off 'feathering' is the tapering of the edges of the remaining paint by rubbing down to provide a smooth surface for overpainting.


The external surface of a building; the external elevation.

Facing brick

A type of brick of better quality and appearance then common brick.


The change or loss of colour through exposure to the ultra violet
content of sunlight etc.


Glazed pottery and hence glazed terracotta bricks used for facing work on buildings.


Breakdown of a paint film such as cracking, flaking, blistering etc.

False body

Also known as 'Thixotropy'. Usually refers to gel type paints which in the tin appear to be very thick or even solid. When applied by brush or roller the gel structure breaks down and the paint becomes liquid thus allowing ease of application.

False ceiling

A lower dummy ceiling suspended below the main structure to improve appearance or proportions or to hide pipes structural steel etc.


Properly a window shaped like an open fan over a door or opening. From this it is often used to describe any shaped window in such a position.


A broad flat surface or member over a shop from or below a cornice; a board carrying a gutter around the eaves of a building.

Fat edge

A heavy accumulation of paint at the edge of a painted surface.


An increase in the viscosity of a paint on storage. Also called 'feeding'.

Feather edged

Boards tapered to one thin edge to allow for neat over-lapping when used for cladding a structure.



See 'reinforced concrete'

Fiberous plaster

Plaster slabs mouldings or ornament made up from wood laths course canvas and plaster and case in the desired form before fixing. Also called 'stick and rag work'.

Fibre board

Building board made from fibrous material such as wood pulp or other vegetable fibre. The term is normally used for the hard-pressed board the soft board being termed 'insulation board'.

Fibre brushes

Brushes with a vegetable fibre filling and which are suitable for applying limewash because the fibres do not soften in contact with lime unlike bristles. Fibre is often used together with pure bristle and are often very effective for applying textured masonry paints.


A composition for levelling off the finer defects of a surface often after the coarser defects such as cracks have been made good with a hard stopper. A filler is applied with a filling knife or a broad knife.

Film formation

The paint's ability to form a continuous dry film. In a latex paint this process is the result. of the water's evaporating and the coming together of the binder particles. A continuous dry film repels water.

Finish coat

The last coat applied in a multiple coat paint system e.g. primer undercoat with a gloss finishing coat.


A small brush with a round oval or flat ferrule usually with a filling of white bristles. They are available in assorted sizes and among their uses are 'picking out' details of plaster ornament ruling painted lines and spot priming fine cracks and small areas.


The detachment of pieces of paint from the substrate caused by a loss of adhesion and elasticity. Also known as scaling.


The application of an intensely hot flame (usually oxy-acetylene) to a steel surface in order to remove heavy rust or scale.


The side of a building; the side surfaces of a building stone; any large internal wall area.

Flash point

The maximum temperature to which a product confined in a closed cup must be heated for the vapours emitted to ignite momentarily in the presence of a flame.


A fault usually in non-glossy finishes, in which patches of uneven gloss occur/appear especially at the joints or laps.

Flashing off

Terms used to describe the action of a period during which the major proportion of the volatile solvent evaporates from a paint film.


Another term for 'matt' and refers to paints which dry without a gloss although some low angle sheen may be apparent.


A common type of brick usually of pink and yellow colour having sharp edges and deep frog.


A plasterers trowel made of wood or metal and used to apply the second coat of plaster in a three coat system. Hence to apply this coat is called 'to float' see 'plastering'.


A defect apparent in a dried paint coat in which streaks or patches of a different shade or colour can be seen especially along edges or mouldings.


During drying one or more of the pigments in a paint separates or floats apart from the others and concentrates in streaks or patches producing a variegate effect.


The extent to which a paint is able to level out after application. Gloss paints usually have good flow resulting in a smooth finish free from brushmarks.

Fluorescent coating

Paints which 'glow’ or show greatly intensified brightness and colour when subjected to certain types of lighting usually ultra violet light. The phenomenon ceases immediately the light source is cut off.


Panel level with the surrounding beading or framing. Hence flush-panelled door where a single smooth unbroken surface is obtained.


The lowest part of a wall or column standing immediately upon the foundations.


Any moulding or structure surrounding a panel or opening hence door frame window frame. Also used to describe the basic structure of a building especially of timber or steel construction.


In classical architecture the area between the cornice and architrave. Commonly the plain or decorated upper part of a wall immediately below the ceiling or cornice and above the border or picture rail.


The depression in one or both sides of a brick in order to form a key for the mortar.


Colouring matter which readily suffers partial or total loss of its original colour on exposure to light or weather.

Fugitive colour

Description of a paint or pigment which fades on exposure to light or weather.

Full coat

As heavy or thick a coat of paint as can be applied in a single application consistent with satisfactory appearance drying etc.


Substances which are capable of destroying moulds and fungi. Solutions of fungicide are used in the painting trade for sterilising mould infected surfaces prior to the application of paint. Also incorporated in various types of paint to give protection against further attack.


Surfaces where the colour has faded due to exposure to ultra violet sunlight should be thoroughly cleaned down to removed all dirt, grease and surface contaminants. Then rub down with a suitable abrasive, dust off and paint over.


This is known as 'flashing'. It's a fault in the paint which causes such patches to appear, especially at joints or laps. You'll need to repaint the surface, first cleaning it thoroughly to remove all dirt, grease and surface contaminants. Then rub down with a suitable abrasive and dust off before painting.


You're using the wrong type of roller. For instance, if you use a sponge roller to apply water-based paints, air is injected into the wet paint film and the air bubbles burst, forming craters on the surface which dry unevenly. As a rule of thumb, use short pile rollers for flat surfaces, medium pile rollers for medium textures and long pile rollers for textured surfaces. After rolling, some paints, particularly solvent-based gloss, may need to be 'layed-off' with a brush to eliminate foaming. To repair a foamy surface, thoroughly clean it down to remove all dirt, grease and surface contaminants. Rub down the surfaces with wet and dry abrasion and water or a suitable solvent. Finally, rinse down and allow to dry thoroughly before repainting. If this is impractical, line the walls before repainting.



The triangular upper part of an external wall formed by the sloping ends of the roof.

Galvanised iron

Steel or iron that has been zinc-coated generally by immersion in a bath of molten zinc.


A condition in which a paint changes usually on storage into a jelly-like state and cannot be restored to a usable condition.


A composition for executing designs in relief on woodwork and plaster – made of whiting and glue or plaster of Paris and size.


In painting this refers to a transparent or lightly pigmented coating used to modify the previously applied coating to produce a rich effect in depth.


When used as a painting term denotes the application of a thin translucent coloured coating to produce an effect or depth of colour not obtainable by the use of a fully pigmented paint.

Glazing bar

The shaped and rebated narrow member of metal or wood into which glass is bedded or fixed.


The extent to which a painted surface reflects light. The degree of gloss may be described as ranging from: matt or flat (having no visible gloss); eggshell; semi-gloss; full gloss (usually meaning the highest obtainable gloss).

Gold size

A general description for an adhesive used for affixing gold leaf. It can be either a gelatine or glue-size or an oil-varnish. The latter product is now usually meant and is also used as a drier in oil paints or a hardener/drier for stopping and filling compounds. It should more correctly be termed 'Japan gold size'.


Pure gold beaten out to produce an extremely thin leaf (approx. 1/2000 000 of an inch) and applied to surfaces to be gilded.


A method of painting with opaque colours that have been ground in water and mixed with a preparation of gum; also any picture painted by this method.


A method of imitating the grain of wood by the application of semi-transparent coat or coats over a painted groundwork. It should not be confused with 'staining' which is the direct application of a coloured stain or coating direct to bare timber.


When a paint does not completely obliterate the under-surface the latter is said to be 'grinning through'.


A general term for a surface suitable for painting; also used for an undercoat particularly an undercoat for graining or glazing.


Thin fluid mortar or cement mixture for filling joints or interstices or for bonding loose rubble.


A hydrous crystalline calcium sulphate used as an extender pigment in some paints and in special cement paints and is the basis of some wall plasters.


Graffiti is a very difficult problem to deal with and may require a specialist removal company in the most severe cases. Normal decorative paints are not suitable for painting over graffiti as many felt marker inks and aerosol spray paints tend to bleed through conventional coatings. Take great care when attempting to remove graffiti from unpainted surfaces, especially when the substrate is porous. To avoid permanent damage to the affected area it may be best to seek professional advice.


When an under-surface shows through a painted surface, it is said to be 'grinning through'. This can happen when a paint fails to completely cover the under-surface, or when an incorrect undercoat has been used for a gloss system. To correct the grinning, thoroughly clean down the surfaces to remove all dirt, grease and surface contaminants, rub down with a suitable abrasive, dust off and repaint.


Hair cracks

This usually refers to very fine cracks which occur in plaster or cement rendered walls and which are often not seen until the surface is being painted. These cracks are too fine to 'fill' and the only remedy is to apply lining paper. On external walls the use of an aggregate type coating will often give satisfactory results.

Hard dry

This term is normally used to denote that the paint has dried without 'tack' or 'softness'. In the case of primer or undercoat a hard dry surface is one which can be rubbed down without undue clogging of the abrasive paper and which can be safely overcoated.

Hard gloss paint

General term for an oil-varnish bound paint originally used to distinguish such paints from those based solely on a drying oil.

Hard stopper

A drying or setting material which is sufficiently stiff to stop up open joints and holes in timber without sagging and which will not shrink when set. Usually applied with a putty knife or small trowel. Bare surface should be primed before applying a hard stopper.

Hard stopping

A material in stiff paste form usually applied by knife to fill deep indentations cracks or joints in a painted surface. It dries hard through and should not be confused with ordinary putty.


Hard-pressed fibre building board.


Wood from a tree of the botanical group of trees that are broadleaved and usually deciduous. The term has no reference to the actual hardness of the wood.


A stone or brick laid across the thickness of the wall. On the face of the brickwork only the end of the header is visible. Opposite to 'stretcher'.


Inner zone of wood that in a growing tree has ceased to contain living cells. It is usually more durable than the outer zone of sapwood.

Heavy body

See 'body'

Hiding power

The ability of paint to hide or obscure a surface colour of stain over which it has been uniformly applied. Hiding power is provided by the paint's pigment


A term used to define a small area missed during the application of a paint coating e.g. where during application of a gloss paint a small area of undercoat is left unpainted.

Hot surface

In the painting sense this denotes a highly absorbent surface which tends to take up the liquid content of paint very rapidly.


The attribute of a colour that determines whether it is red yellow green blue purple etc.


Almost a synonym for 'hot' and indicates a porous surface that quickly absorbs paint applied to it. It is also sometimes used to describe the appearance of a paint film that has been affected by the excessive porosity of the surface beneath - hence is applied to any thin coating with poor 'build'. Alternatively the term 'starved' may be used.


A thin coating applied over a porous surface can often have poor 'build', known as a 'hungry' coating. The solution is to thoroughly clean down the surfaces to remove all dirt, grease and surface contaminants, then rub down with a suitable abrasive and dust off. Prime the whole surface with a suitable primer before repainting.



An impervious paint system is one which will prevent the passage of moisture or moisture vapour.

Inert pigments

Materials which are resistant to attack by chemicals normally encountered in the environment in which they will be used e.g. atmospheric pollution.

Insulation board

Commonly refers to soft fibre board but can also be used for similar boards of any composition.


To swell enlarge or expand when exposed to heat. Many fire retardant materials have this property.



The sides or vertical side posts of a door window or other opening.


An abbreviation of 'Japanning' which is the process of finishing with a stoving black called Japanners' Black or Black Japan. Hence also Japanners' gold size or Japan gold size.


Horizontal timbers or metal girders to which floors and ceilings are attached.


Keenes cement

A quick-setting, hard wall plaster, slower in set than plaster of Paris and normally used to produce hard, well-trowelled surfaces.

Keep alive/keep open

Refers to the condition of a paint which has been applied for a short while but is still in a sufficiently liquid condition to be successfully joined up and to dry without showing the lap.


As a paint term this refers to the slight roughness of a surface which enables a coat of paint to achieve good mechanical adhesion to the surface.


The central locking stone in an arch.


A solution of shellac in methylated spirit used for treating knots and resinous timber to prevent stains from the timber discolouring the paint. It cannot be expected to hold back resinous exudation.



A term usually applied to coatings that dry entirely by evaporation of the solvent.


The process of covering vessels or pipes with a non-conducting material to prevent loss or ingress of heat.


A milky type deposit from newly applied concrete.

Lantern light

A rectangular projection on a flat roof, usually with vertical sides and wholly or partly glazed to admit light and air to the building beneath.


In painting, the expression 'to lap' refers to the joining up of a section of painting to a previously painted, but still wet, section. Normally it is important for the previously painted edges to be 'kept alive' so that the paint can be well worked into the previously painted section and subsequently dry without the lap showing.

Latex paint

Water-based paint made with synthetic binders such as 100% acrylic vinyl, acrylic terpolymer or styrene acrylic. Latex paint dries fast, flows smoothly and cleans up easily with water.

Lath and plaster

Describes a form of ceiling or wall construction in which narrow strips of wood are fixed to the framing or joists over which plaster coatings are spread.

Laying off

The final brush strokes on any surface during a painting operation. These strokes are made after the paint has been spread evenly over the surface.


A window fixed horizontally in a ceiling to admit light (natural or artificial).

Lead paint

Usually refers to a paint based on white lead or red lead but more widely can mean any paint containing a lead pigment.


Certain metallic pigments such as aluminium in the form of thin, flat flakes (as distinct from the granular form) which float to the surface of a paint coating and slightly overlap each other, forming a 'barrier' to help prevent staining from previous coatings or substrate.

Legged and braced door

A door formed of boards fixed to a frame with diagonal bracing pieces.

Let down

To dilute a material usually to improve application properties.


The ability of a coating to form a smooth film without brush marks appearing.


The softening and disturbing of an existing coat of paint when a further coat is applied over it and usually causing a wrinkled effect to develop.


Any glazed opening, window, etc. is termed a light.

Light fastness

The degree of resistance to colour fading of pigments in paint on exposure to light.


A white or pale coloured coating for brickwork, stucco, cob, walls, etc. which is made from freshly slaked quicklime to which a binding agent such as tallow has been stirred in while still hot. Pale colours are obtained by tinting with lime-fast dry pigment.

Lining paper

A plain 'wallpaper' for use as a ground for painting or wall hangings. Usually white or creamy white in colour and generally used for high quality work and to disguise surface defects in plaster which cannot be overcome by normal preparation.

Linseed oil

An oil obtained by crushing flax seed. Its drying properties make it suitable as a paint medium but it is now used mainly for modifying synthetic resins.

Live edge

During the process of painting large areas some edges of the wet paint will have to be left for a period while the remainder of the work is brought level. If these edges are still capable of being joined without a lap showing they are said to be 'live'. The art of the painter is to coat the whole surface keeping any such edges 'alive' so that the finished work shows no joints or laps.

Lock rail

The horizontal member or rail of a door in which the lock or latch is fixed.

Long oil

Term used to denote the properties of oil and resin in a vanish. A long oil varnish should contain not less than 70% drying oil. Terms for other proportions: short oil for 45-50% drying oil; medium oil for 50-70% drying oil.

Luminous paint

A paint containing a phosphorescent pigment which glows in the dark after exposure to light.


Properly a small vault in a larger vault, but commonly used to describe a semi-circular panel or light.


A term used to describe a particular degree of gloss, e.g. an eggshell or low gloss finish.


A new coat of paint can sometimes soften the previous coat and cause wrinkling or 'lifting'. This can be the result of using a different type of new coating over the existing paint, or by applying a second coat before the first coat is fully dried. To solve the problem, thorough clean down the surfaces to remove all dirt, grease and surface contaminants. Scrape back all poorly adhering or defective coatings to a firm edge and rub down to 'feather' broken edges. Dust off an apply new coat.


Abbreviation for mild steel.

Making good

Carrying out the requisite repairs to a surface to provide a sound surface for painting.

Match boarding

Boards jointed at their sides with a tongued and grooved joint.
Matt finish

A flat finish with little or no sheen.


A liquid component of paint in which pigments are dispersed and which forms part of the dry paint film.

Metal spraying

Describes the process of spraying molten zinc or aluminium on to grit-blasted steel to provide protection against corrosion.


An apparent change in colour under different lighting conditions.


Mineral silicates used in the manufacture of textured paints.


A term used to describe paints which are permeable to water vapour allowing moisture to dry out through the paint coating without disruption of the paint film.


Chemical agent in quality paint that destroys mildew - a common problem in humid climates.


Iron oxides, usually black in colour, which can be present in a complete layer on new steelwork. Although often firmly attached originally it can become loose and thus give rise to paint failure. Millscale should be completely removed prior to painting.

Mist coat

A thin and thinly applied coat of paint, usually emulsion on bare plaster, which acts as a 'sealer'.


A joint between two pieces at an angle to one another so that the line of the joint bisects the angle.


Solution or preparation applied to a surface to assist paint to adhere thereon, e.g. on galvanised iron.


A mixture of lime or cement and sand used as the jointing mixture for bricks or stone.


A cavity cut into a piece of wood or stone to receive a corresponding projection (called a tenon) so as to form a strong joint.


The upright frame member or division between the lights of a window or openings in a screen.


A system of designating colour by colour, hue and chroma.


The vertical framing member or stile between the panels of a door.


Unfortunately, no. You’ll need to thoroughly clean down the surfaces to remove all dirt, grease and surface contaminants. Then rub down with a suitable abrasive and dust off before applying a new coat of paint to the affected area.

Mould growth on inside surfaces

Mould flourishes in conditions of high humidity, poor ventilation and on surfaces with a high moisture content. It can be very destructive to paint coatings and needs to be eradicated before applying paint. Treat affected areas with Weathershield Multi-Surface Fungicidal Wash. Leave for 24 hours, wash down to remove residues and allow to dry thoroughly. If necessary, repeat the treatment.

Mould/algae moss on outside surfaces

Yes, there is a very effective treatment for these types of vegetable growths, which are most likely to occur in damp conditions or on surfaces with a high moisture content.. Before treating, first repair the source of any leaks and check for blocked air bricks and defective or missing DPC. Treat affected areas with Weathershield Multi-Surface Fungicidal Wash. Leave for 24 hours, wash down to remove residues and allow to dry thoroughly before applying coating. Isolated algae patches on a building exterior may indicate structural defects and should be investigated by a reputable builder or building surveyor.

Mud cracking

It has most likely been caused by applying a thick, heavy coat of un-thinned paint to a textured or embossed surface. 'Mud cracking' can also be caused when the air temperature drops rapidly after applying a water-based product, or when over coating an emulsion without leaving sufficient drying time. The solution? Applying one or two thin coats will often successfully fill the cracks.



The central post or wall (newel post - newel wall) around which a staircase is formed. Hence the main supporting posts of a staircase that continue upwards to form the ends of the balustrading.



The quality or degree that a coat of paint hides the underlying surface; opacity.

Oil length

See 'long oil'


Generally refers to varnishes composed of vegetable drying oils in conjunction with resins which may be either natural or synthetic.


The ability of a coat of paint to obliterate the surface to which it is applied.

Orange peel

The 'dimple' effect on a paint coating. With spray application it is often caused by insufficient thinning. With roller application it is usually caused by insufficient thinning and/or type of roller used.


The process whereby substances combine with oxygen. Oil paints dry by oxidation of the oil content.

Orange peeling

When spraying, insufficient thinning can create this 'dimple' effect on a paint coating. The same is true when using a roller, or it could be the wrong type of roller for the product used. In any case, to correct the fault, thoroughly clean down the surfaces to remove all dirt, grease and surface contaminants. Rub down with wet ' dry abrasion, using water or a suitable solvent, then rinse down and allow to dry thoroughly prior to applying a new paint coating.


Paint deodorants

Aromatic materials which are added to paint to mask paint odour.

Paint remover

A liquid composition that is applied to a dry paint film and softens it sufficiently to permit its removal by scraping.


A low wall built along the edge of a roof bridge or other structure; the continuation of the main wall above the eaves level to form such a wall.

Patch prime

The priming of localised bare surfaces when bringing forward, prior to stopping up and/or painting.

Pebble dash

A rough finish given to external walls by coating it with mortar or cement and sand and throwing small pebbles onto the surface before it has set.


The detachment of paint from the surface in ribbons or sheets. Like flaking, it is the result of loss of adhesion properties.


A term used to indicate the degree to which a paint system will meet the requirements of any specific job, e.g. an interior quality paint would give poor performance (would have poor durability) if used on exterior surfaces.


A paint system which is said to be permeable when it allows water vapour to pass through the paint film, i.e. the paint allows the substrate to breathe.

Petrifying liquid

Usually a dilute emulsion of drying oil and/or varnish in water used as a sealing coat on surfaces under water paint or as a thinning agent for water paint.


A synthetic resin used in the manufacture of some industrial finishes.

The treatment of steel or other metal surfaces or articles with solutions containing phosphates and phosphoric acid to produce a coating which inhibits corrosion and assists paint adhesion.

Picking out

The individual colour treatment of ornamental units and/or mouldings in cornices and similar architectural features.

Picking up

This has two meanings:

  1. The process of joining up to 'wet' or 'live' edges on lapping.

  2. The lifting or softening of a previous coat of paint when applying a subsequent coating.


The treatment of steel by immersion in a special acid solution in order to remove millscale (acid pickling). Alternatively, a method of removing paint varnish or varnished wallpaper with a strong alkaline solution. Hence any alkaline cleaning solution may be referred to as 'pickle'.


The supports of the arches of a bridge; area of plain wall between arches or openings. Hence is commonly used to describe any rectangular projection in a wall flank.


This powder like substance is one of paint's basic components (the other is the binder). The pigment gives the paint its colour and hiding power. Titanium dioxide is the most important pigment used to provide hiding in paint.


A square pillar, often purely ornamental, projecting from a pier or wall, often in symmetry with a line of columns.


The formation of minute holes in a paint film during application and drying.


A tube usually for the conveyance of liquids.


  • A dark coloured bituminous substance.

  • The angle of a sloping roof to the horizontal.


The horizontal section of a building as shown on a drawing.
Plaster board

A building board having a plaster core between two layers of stout paper.


The operation of applying plaster and other similar materials to structures to produce a smooth surface. The normal process consists of three coats: (1) rendering, (2) floating, (3) setting.

Plastic paint

A plaster composition which can be manipulated after application to produce a patterned or modelled effect. The description should not be used for paints based on synthetic resins.


A synthetic type of resin used in the manufacture of some types of masonry paints. Pliolite is the trade mark of the Goodyear Tire & Rubber Co. Inc.


Filling the joints in brickwork or masonry with mortar.


A measurement of viscosity.


This binder is produced from petrochemical feedstocks. The binder's polymer particles are small in size and carried in water. The binder polymer and water mix is known as emulsion.


The degree to which a material will absorb liquids.

Pot life

This refers to the period during which a two-pack material remains useable after mixing.


The initial treatment of a surface prior to painting, e.g. treatment of galvanised metal with mordant solution or sterilising surfaces with fungicidal solution.


Usually used to indicate the chemical treatment of bare metal prior to painting.


The first coat of paint applied to a surface which is then the foundation for subsequent coats.


Member laid horizontally across the main rafters or roof trusses and supporting the common rafters.


A short piece of timber or tube used in scaffolding to support the boards.


A composition usually made from linseed oil and whiting and used mainly for bedding glass into primed wooden window frames.


Abbreviation for Polyvinyl Acetate which is used as a medium in emulsion paints.


Pigment volume concentration. The ratio of the volume of pigment to the volume of total non-volatile material (i.e. pigment and binder) present in a coating. The figure is usually expressed as a percentage.


This is caused either by different levels of porosity in the substrate or by uneven application. Usually, one more coat will rectify the problem. Before applying, thoroughly clean down the surfaces to remove all dirt, grease and surface contaminants. Rub down with a suitable abrasive, dust off and apply coating.


Like flaking, peeling results from paint losing its adhesion properties. The cure is to thoroughly clean down the surfaces to remove all dirt, grease and surface contaminants, then scrape back all areas of poorly adhering or defective coatings to a firm edge. Finally, rub down to ‘feather’ broken edges, dust off and repaint.

Picking Up

There are two meanings for this term. One is the process of joining up to ‘wet’ or ‘live’ edges on lapping; the other meaning concerns the lifting or softening of a previous coat of paint when applying a new coat. The remedy in both cases is to thoroughly clean the surfaces to remove all dirt, grease and surface contaminants. Then scrape back all areas of poorly adhering or defective coatings to a firm edge, rub down to ‘feather’ broken edges, dust off and apply a new coating.


If minute holes appear in the paint film while applying or during the drying phase, it's likely due to the surface being contaminated by oil, grease or a similar substance. Apply a new coat, after first cleaning down the surfaces to remove all contaminants, rubbing down with a suitable abrasive and dusting off.

Poor gloss level on new paintwork

Condensation forming on the surface soon after application can take the gloss of new paintwork. This can be caused by painting in cold, damp conditions or painting outside when rain or frost are imminent. Porous under-surfaces can also absorb gloss and make it appear dull. To remedy, lightly abrade the surface and apply a further finishing coat of paint when conditions more favourable.

Powdery/chalky surfaces on outside paintwork

Powdery or chalky old paintwork is caused by the paint film wearing away due to exposure to weather. This natural erosion of the paint coating can often be removed by thoroughly washing down prior to repainting. If washing doesn't remove a chalky surface, seal with primer before painting, or in severe cases remove the chalky surface entirely.

Powdery/chalky surfaces on plaster

Powdery and chalky surfaces are quite common in older properties that have been painted with distemper or white wash. You should completely remove these coatings by washing with warm water and a detergent solution. Rinse with clean water and change the water regularly. If the surface still remains slightly chalky, seal with an appropriate Dulux primer or plaster sealer prior to finishing.

Powdery/chalky surfaces on previously painted exterior masonry

Brick and masonry surfaces painted with cement-based paint will eventually corrode and become powdery or chalky. Even unpainted pebbledash or render can become powdery with age. In each case, ensure the surface is sound, clean and dry. Remove all loose material with a stiff brush or paint scraper. If powdery or chalky residues still remain, stabilise the surface with a coat of Weathershield Stabilising Primer. However, don't use a stabilising solution on new or sound bare rendering that has never been painted. A well-thinned first coat of the appropriate Weathershield Masonry Paint is usually all that is required.



A bill of quantities sets out the measurements and amounts of work to be done on a building contract and is divided into sections according to the trades.


Properly a groove in a moulding between a convex member and a flat fillet but commonly used for any groove.


The external angle of a building.



See 'rebate'


A member in the roof structure running from the ridge to the eaves.


Horizontal piece of timber in framing or panelling; any horizontal piece of timber.

Rain spotting

Depressions or surface blemishes in a paint film caused by rain falling on the surface before the paint has fully dried.

Raking out

The process of cutting out cracks in plaster or rendered surfaces to remove loose particles and to provide a key for the repair material.


A recess cut into a piece of timber so as to fit into another piece to form a joint; a recess in a frame to accommodate a door panel or window. Also spelt 'rabbet'.

Reinforced concrete

Concrete work in which steel bars (reinforcement) are embedded to impart additional strength. Should not be confused with a load-beaming steel structure, clad or covered with concrete.


The first rough coat of a plastering system usually composed of lime and/or cement and sand; External 'plastering' on walls and application to all coats in the system -also 'cement rendering'.


Term used to describe any gum or resin used for varnish and paint manufacture. In case of synthetic resin the term will embrace liquid syrups as well as the solid material.


The interior surfaces of a bay are the reveals; also used to describe a 'return' of a wall into a window or door opening.


The vertical face of a step or stair.


See 'shrivelling'

Roof light

Any form of skylight usually in a pitched roof but also sometimes used as a general term for any window or light in a roof.


The appearance of a paint film which shows coarse or heavy brush marks.

Rough cast

A term often used incorrectly for rough-surfaced rendering; correctly the term applied to a final coating of small stones or chippings mixed with a liquid mixture of mortar or cement and sand, and 'cast' or thrown onto the wall or rendering to produce a rough-textured finish.


Describes a heavy-bodied paint or one having good build and opacity.

Round coat

Usually refers to the liberal application of a full coat of paint.


Rolled steel joist.

Rubbing down

Preparation of a surface by use of abrasive materials, e.g. glasspaper to obtain a smooth surface for painting over or to provide a 'key' for subsequent coats.


Narrow dribbles or tears of paint caused by excess flowing out of crevices and quirks or from edges or corners and usually due to insufficient spreading or care during application.

Rustic brick

Bricks having a rough-textured surface, often multi-coloured and probably derived from rusticated masonry which is composed of unhewn stones.


Rain water head; the hopper or box at the top of a rainwater pipe into which several gutters or pipes discharge.


Rain water pipe.

Rain spotting

There's only one way to remove depressions or surface blemishes caused by rain spotting. Clean down the surfaces to remove all dirt, grease and surface contaminants. Then rub down the surfaces with Wet ' Dry abrasion, using water or a suitable solvent. Finally, rinse down and allow to dry thoroughly before applying a new coat of paint.


Coarse or heavy brush marks are most likely caused either by painting onto a very porous surface, or applying paint in warm conditions. To get rid of the marks, first clean down the surfaces to remove all dirt, grease and surface contaminants. Rub down with Wet ' Dry abrasion, using water or a suitable solvent. Finally, rinse down and allow to dry thoroughly before applying a new coat of paint.

Rotten wood

Simply run a pen knife blade across the grain. This will only make a small indentation on sound timber, but on rotten timber the blade will sink in. The only cure is to cut out all the rotten wood and replace with sound timber.


Sagging (curtaining)

Usually occurs on vertical surfaces where paint has been too thickly and unevenly applied resulting in 'horizontal runs' with a thick lower edge.

Sand blasting

Grit and sand-blasting are processes used in the preparation and cleaning of steel to remove millscale and corrosion products. They are highly specialised processes.


The use of an abrasive to level a surface prior to painting. The more common term used by painters is 'rubbing down'.


In the paint trade it refers to the chemical attack of the paint media by alkali usually from the substrate. e.g. the alkali reacts with the oil content of an oil based paint and turns it into a soap, resulting in disintegration of the paint. Oil based paints are very susceptible to saponification whereas emulsion paints generally have good resistance to alkali attack.


A bituminous underlay placed beneath tiles or slates.

Sash window

A window in which the opening parts slide up and down in the frame.


A band of plaster or mortar laid on the surface of the wall as a guide to the thickness or level of the plaster to be applied. Therefore also used for the coat itself and for the levelling coat on flooring.


A technique in painting where by the final coat is patterned or partly removed to expose the undercoat or ground in order to obtain colour variety or movement.


Any outline drawing showing the shape of a moulding structure or object as it would appear if cut along a line and viewed at right-angles to the cut; particularly refers to the drawing of a building prepared in this way as opposed to a plan or elevation.


The appearance of very small particles in the dried paint film.


An intermediate level of gloss between a 'full gloss' and an 'eggshell' finish.


The condition of a paint coating when it has ceased to flow.
Setting coat

The final coat in a plastering process usually consisting of about one-eighth of an inch of fine plaster.


The deposition of the solid particles of a paint to the bottom of the container.

Sharp coat

Strictly speaking it is an application of a white lead/linseed oil paint liberally thinned with white spirit or turpentine. By dint of, this 'sharp' has come to be used for any thin and/or quick drying paint.


A variation of sheen or gloss in a dried paint coating producing an uneven patchy appearance.


An irregularity in gloss or sheen on a surface.


The degree in gloss of a low gloss or matt type finish.

Shop priming

Factory application of primers to wood or metal, etc.

Short oil

The term used to describe a varnish or paint medium which contains a low proportion of oil in relation to its resin content.

Shot blasting

See 'sand blasting'


The overall fine-surface wrinkling of a glossy paint film.


The general term for temporary supporting structures for concrete while it is setting. Also from work.

Silk or satin finish

A finish with a low to medium degree of sheen or gloss.


The lowest timber or member in a structure frame or opening. The timber or stone at the bottom of a door or window opening.


Loss of gloss or colour due to the absorption of the medium by the undercoat or surface beneath.


A common type of hardwall plaster. It may or may not be mixed with lime.


A mixture of glue and water.


A board or member at the base of a wall, probably a corruption of 'wainscotting'.


Condition of a recently-dried glossy paint film which has lost its initial gloss slightly.


The description of a recently applied gloss paint which has a 'hazy' appearance or lower than normal gloss.


A thin paste produced by mixing some materials, especially Portland cement with water.


A term used for a mixture of paint with remainders of all types and colours.


The underside of a staircase or of the head of an opening such as a door window or arch. Hence also used for the underface of a beam or for any small ceiling at a different level to a main ceiling.

Softwood timber

Timber from trees with needle shaped leaves mostly evergreen e.g. conifer. This term has no relationship to the actual hardness of the wood. This timber is most commonly used in house construction.

Soil pipe

A vertical lead or cast iron pipe conveying waste matter from WCs, etc. to the drains. Unlike a rainwater pipe it will have sealed joints and is usually continued above eaves level to form a ventilator.


A liquid component used in paint to bring it to a suitable consistency for use and which evaporates from the paint after application. Also a liquid which will dissolve dried paint, e.g. cellulose thinners on cellulose; chlorinated rubber paint thinners on chlorinated rubber paint.


The horizontal distance between the supports of an arch roof or beam, etc.


The triangular area formed between an arch and the horizontal member it supports, hence ‘spandrel panel’ - the shaped panel formed in the spandrel.


Droplets of paint that spin or mist off the roller as paint is being applied.

Spot priming

The priming of localised bare timber surfaces when 'bringing forward' prior to stopping up and/or painting.


Application of paint by a spray gun. Two types of spray are available: 'conventional' which is operated by compressed air, and 'airless' operated by hydraulically compressing the paint.


The action of applying paint by brush in a uniform coat over a surface; colouring bare wood by means of a dye or stain; discolouration of a paint film.

Spreading rate

The area which a given quantity of paint will cover, e.g. the spreading rate of a particular paint may be quoted as '15m2 per litre on smooth surfaces of average porosity'.


A prop or support to a roof ceiling or beam. Especially refers to cast iron or rolled steel member used as a supporting column.


See 'hungry'


The treatment of surfaces to kill off organic growth such as mould or algae prior to painting.


The vertical part of any framing into which the horizontal rails are fixed by mortices and tenons.


A method of evening out a coat of paint by dabbing or lightly beating out the surface immediately after application with a special brush (stippler). Hence the texture or appearance of a paint surface so treated.


The action of filling up joints, deep imperfections or holes in a surface before painting.


The process of drying and hardening a paint coating by heating in an oven or other apparatus.


A stone or brick laid so that its length is in the line of the face of the wall. Opposite to 'header'.

String course

A projecting course of stone or brick continued horizontally along the face of a wall.


The supporting board of a staircase farthest from the wall.


The removal of old paint or paper.


A smooth-surfaced cement or rendering applied to external walls, especially if it resembles stone.


The surface or composition of the structure which is to be painted.


Term loosely applied to paints containing a proportion of, or based entirely upon a synthetic resin. The use of the term should be avoided as it is not sufficiently precise.

Sags and runs on new paintwork

This is usually caused by uneven paint application on broad, flat surfaces, or by over-applying on mouldings or rough-contoured surfaces. Also, failing to join up 'wet edges' before they have set can cause excessive film thickness, resulting in sagging and running. When the paint film is thoroughly dry rub down the sags/runs using wet and dry abrasive paper (or waterproof silicon carbide) together with warm water and detergent. To prevent sags/runs when painting broad, flat areas, work systematically and cross-brush each section into the next; finally using vertical strokes to gently lay off along the length of the surface.

Salt staining on plywood

Salt staining can appear on wood stained exterior grade plywood, especially on eaves and soffits. Salts are contained in the adhesive used to bond the layers of plywood together. Because wood stains are very permeable, they can bring these salts to the surface of the wood. Rainwater will normally remove these salty deposits, except in sheltered areas such as soffits and eaves. The only way to remove these deposits is to wash them down until they no longer appear. For further guidance, see BS 6150 Section 26.

Saponification of oil-based paints on plaster

Saponification occurs when oil-based paints are softened and liquefied by the alkali in plaster when moisture is present. Materials containing Portland cement or lime are strongly alkaline; gypsum plasters are usually not, but can become alkaline if gauged with lime or if it is brought forward from the backing during the drying phase. For these reasons, never use oil (solvent) based paints on plaster or masonry surfaces until they are completely dry in depth, then prime the surfaces with Dulux Alkali Resisting Primer. Where saponification has occurred, completely remove the defective coating, wash down the surface and rinse with clean water. Allow to dry then prime with Dulux Alkali Resisting Primer.


There's really only one solution to this one: thoroughly clean down the surface to remove all dirt, grease and surface contaminants. Rub down with a suitable abrasive, dust off, and re-paint the affected area.


This variation of sheen or gloss in dried paint is known as 'sheariness' and is often seen in brushed emulsion paints when viewed from a shallow angle. To correct this condition, thoroughly clean down the surfaces to remove all dirt, grease and surface contaminants. The scrape back all areas of poorly adhering or defective coatings to a firm edge, rub down to ‘feather’ broken edges, dust off and repaint.

Shrivelling (or rivelling) on new paintwork

Known as 'shrivelling' or 'rivelling', this wrinkling effect can occur when paint dries too quickly, forming a surface skin before the paint underneath can dry properly. Overcoating a previous undercoat or gloss to soon can also cause shrivelling, as can applying oil-based coatings at low temperatures. Before attempting to smooth out the wrinkles, allow the surface to dry and harden, then rub down using wet and dry abrasive paper with warm water and detergent. Rinse thoroughly with clean water and allow to dry before repainting.


When the gloss or colour of the coating has been absorbed by the undercoat or the surface beneath the coating, first thoroughly clean down the surfaces to remove all dirt, grease and surface contaminants. Then rub down with a suitable abrasive and dust off before priming all over with a suitable primer for the finishing system.


Apply another coat of paint, after first cleaning down the surfaces to remove all dirt, grease and surface contaminants. Then rub down with a suitable abrasive, dust off and repaint.

Slow drying of gloss/varnish on new paintwork

With solvent-based paints, it's usually surface contamination as the result of a poorly prepared surface. Water-based paints can be slow to dry in damp, cold conditions, or when applied to timbers that are oily by nature, such as teak. Wet solvent-based paint may be removed using cloths soaked in white spirit. If this is unsuccessful, completely remove the coating using a hot air gun or a suitable chemical-based remover. To remove slow-drying water-based paints, simply wash off with warm water and detergent solution.

Staining/discolouration of paint on masonry

There are a number of principal causes:

  • Certain types of sand used in the construction or rendering of a building can cause staining, as can certain kinds of brick hollow clay pots or clinker blocks containing soluble salts. Pieces of ferrous metal or iron stone embedded in the material can rust and discolour when the surface is painted. These problems can be treated by sealing the affected areas with Dulux Alkali Resisting Primer when the surface is completely dry.

  • 'Rust'Steel reinforcing in concrete may be too close to the surface and cause rusting. The only effective way to resolve this problem is to get back to the metal itself and treat the cause of the rust. staining can occur where old nails are left in the substrate, or a wire brush has been used to prepare the surface. In this case, prime locally with Dulux Metal Primer prior to painting.

  • Steel reinforcing in concrete may be too close to the surface and cause rusting. The only effective way to resolve this problem is to get back to the metal itself and treat the cause of the rust.

Staining/discolouration of paint on plaster

Past water leaks or burst water pipes can cause staining. Before repainting, ensure that the leak has stopped and the surface is thoroughly dry, then spot prime the affected area with Dulux Alkali Resisting Primer. 2) Heavy deposits of tar from cigarette smoke and around the chimney breast of open fires are common causes of staining, especially on water-based emulsion paints. To prepare, wash the surface thoroughly with detergent solution and rinse frequently with clean water. Allow to dry, then prime with Dulux Alkali Resisting Primer. If using water-based paints, allow a few days for the oil deposits of the primer to disappear, otherwise cissing may be a problem. 3) Conventional solvent-based finishes such as gloss can discolour with age, particularly in areas sheltered from natural daylight. Prior to repainting, wash the surface with a detergent solution, rinse with clean water and allow to dry. It may be more advisable to use a water-based coating for a low light area.

Staining/discolouration of paint on wood

There are different solutions for each of these problems. 1) Staining caused by rust from old nails should be rubbed down to remove the rust, then prime any exposed metal with Dulux Metal Primer or Dulux Q.D. Metal Primer before painting. 2) Resin bleeding from knots in wood should first be removed with white spirit. Then seal the knots with two coats of Dulux White Knotting Solution and repaint. 3) All solvent-based paints such as gloss will discolour or yellow with age. To treat, wash the surface thoroughly with detergent solution, rinse with clean water and allow to dry before repainting. If the wood appears to be dirty, particularly around glazing rebates, it may be affected by fungal growth. Clean the surface thoroughly and treat with domestic bleach, or apply a coat of Aluminium Primer, before painting.


There's only one thing for it. Completely remove all existing material and carefully clean down the surfaces. Allow to dry, then reapply coating.


Tack rag

A fabric impregnated with a special oil or resin which remains tacky. Used to remove dust, etc. from a surface immediately prior to painting.


Large metal container for holding water or other liquid usually completely enclosed and rectangular in shape.


See 'runs'


A label or tab of some material. Often a patch of cement and sand or plaster placed across a crack to show whether any future movement occurs.


The end of a piece of wood cut in a rectangular form to fit into a cavity of the same shape and size cut in another piece (a mortice).


A form of liquid drier for paint, originally a combination of solvent linseed oil and metallic salts. Now tends to be used by the painter for any liquid drying agent.


The thinner and binder together form the paint's vehicle. Water thinner used in latex paints evaporates as the paint dries, allowing a smooth paint application. Turpentine or spirits are the thinners in oil-based paints.


Tested & Approved by Professional Decorators

    Dulux Trade products undergo rigorous testing to ensure that they lives up to decorators’ expectations and genuinely     deliver on the benefits promised. Following laboratory testing under controlled conditions, Dulux Trade asks     professional decorators to review the product in three stages:


  1. Assessments by an internal Dulux panel of professional decorators

  2. Assessments by a panel of external professional decorators

  3. Field trials that put the product to the test under real-life conditions


Also known as 'false body'. Usually refers to gel type paints which in the tin appear to be very thick or even solid. When applied by brush or roller the gel structure breaks down and the paint becomes liquid thus allowing ease of application.


Any coloured pigment or paint mixture used to make small adjustments in colour to an already prepared paint.

Titanium dioxide

A highly opaque inert white pigment. It is the white pigment almost exclusively used in the manufacture of all 'white paint' or in colours which require the addition of white.

Tongued and grooved

See 'match boarding'


horizontal bar of stone timber or metal across a mullioned window. Also the horizontal member separating a door and fanlight.


  • A small door opening in a ceiling giving access to a roof void or in a floor for similar purpose.

  • A bend in a pipe so arranged as to be always full of water and prevent free flow of air or gas through the pipe. Hence S-trap or P-trap indicating the shape of the bend.


The horizontal part of a step or stair on which the foot treads.


Description commonly used for ventilating and other ducting usually, but not always, of metal.

A combination of timber or metalwork so arranged as to make a rigid frame. Especially used to denote roof framing, hence 'roof truss', examples of which can be readily seen in industrial buildings.



Describes the formation of a false ceiling by covering in roof trusses or beams with a light structure of building board or similar material.

A paint coating applied after the primer and before the finishing coat. In relation to timber an undercoat helps fill the grain to give a good basis for a gloss coat and in all cases the use of the right undercoat is essential to achieve the correct colour of the top coat.

Universal colourants

A colourant which can be used for thinning water-thinned and solvent-thinned paints.

Useful life

The period of time during which the paint film is still satisfactorily protecting and/or maintaining its decorative appearance.



A transparent coating based on drying oils and resins.


The vehicle and the pigment are the two basic components of paint. The vehicle is made up of thinner and binder.

Vent pipe

Any ventilating shaft; expansion pipe from a hot water system or other sealed tank or circuit.


The edge of the roof covering projected beyond a gable end.

Vinyl emulsions

Emulsions based on PVA or other vinyl compounds.


A measurement of the consistency and/or other properties of a paint, i.e. thickness or thinness.


Volatile organic content. Any carbon compound that evaporates under standard test conditions. Essentially all paint solvents except water are VOCs. Federal and state governments are beginning to limit the amount of volatile organics found in paint because of the concerns about possible destructive environmental and health effects.

Volume solids

The volume of pigment plus binder divided by the total volume, expressed as a percent. High volume solids mean a thicker dry film improving hiding and durability.



Woodwork lining the walls of a room or passage.


Ease with which washing will remove dirt from the paint's surface without causing damage to it.

Washing off

If you apply a water-based product in cold conditions (i.e. below 10ºC), loss of adhesion can occur and the coating may simply wash off when it rains. To rectify, thoroughly clean down the surfaces to remove all dirt, grease and surface contaminants. Scrape back all areas of poorly adhering or defective coatings to a firm edge and rub down to 'feather' broken edges. Dust off and re-apply coating.

Waste pipe

See 'soil pipe'

Water paint

Any paint in which the 'thinning' agent is water, might strictly be classified as a water paint. However the term has come to mean an oil or varnish bound washable distemper in which the binder, on drying, becomes mainly insoluble in water.

Weather board

Boards fixed to overlap one another to prevent entry of rain etc.

The central part of a girder connecting the two flanges.
Wet adhesion

The ability of dry paint to adhere to the surface, in spite of wet conditions, is particularly important for exterior house paints.

Wet edge

Refers to the condition of a paint which has been applied for a short while but has remained in a sufficiently liquid condition to be successfully joined up and to dry without showing the lap.

Wire cut

A type of brick so called from its method of manufacture in which the clay blocks are cut into shape instead of being moulded or pressed.

Working up

The action of an existing and apparently dry coat of paint being removed by the action of brushing the succeeding coat over it.

The development of wrinkles during drying. Often caused by too thick an application.


Abbreviation for 'water waste preventer', or flushing cistern.



The development of a yellow colour on ageing; most noticeable on white or light coloured paint and clear varnishes.

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