FAQs

What is meant by matt, gloss, silk and satin finishes and what are the typical uses of these paints?

The terms: gloss, satin, silk, eggshell and matt; strictly speaking, refer to the level of sheen of a product. They have, however, also come to be associated with a type of product.

Matt emulsion is suitable for ceilings and walls, including plasterboard, fibre insulating board, hardboard, brick, cement rendering, stucco, foamed polystyrene and most wallpaper. It is touch dry in about 2 hours. Further coats may be applied after about 4 hours. Brushes and rollers may be cleaned in water.

Silk (emulsion), also known as satin finish, is suitable for interior walls and ceilings. It is touch dry in about 2 hours and a second coat may be applied after about 4 hours. Brushes and rollers may be cleaned in water.

Traditional eggshell finishes are solvent based. Surfaces are tack-free in about 4-6 hours but should be left overnight before a second coat is applied. Brushes and rollers need to be cleaned using white spirit or brush cleaner. Water based eggshells are now available. (remove new paragraph) Water-based eggshell finishes are generally quick drying and low-odour. Brushes and rollers may be cleaned in water.

Gloss is suitable for interior and exterior and is used as a protective coating in the decorating market. These are generally used on wood or metal surfaces. Gloss paints may be found which are specifically manufactured for exterior use. Although gloss paints are on the market that require no undercoat, unless otherwise stated surfaces should be suitably primed and undercoated.

Traditional gloss paints are solvent-borne (solvent-based) (see "Water and Solvent-borne paints") Surfaces are tack-free in about 4-6 hours but should be left overnight before a second coat is applied. Brushes and rollers need to be cleaned using white spirit or brush cleaner.

Modern water-borne (water-based) gloss paints are now also available in most DIY and trade outlets. These are quick drying and generally low-odour. Drying and overcoating times vary, but are generally shorter than for traditional solvent-borne gloss finishes. Brushes and rollers may be cleaned in water and detergent.

Varnishes are also available in gloss, satin and matt versions, and as solvent or water-borne products. Their properties will be similar to the equivalent paint, although drying and re-coat times are generally shorter than for corresponding paints.

Please note that the information given above is general and individual products may have different properties. You should always read the container or other information for specific details.

Great care should be taken if painting asbestos-containing material (ACM) such as asbestos cement panels and corrugated sheeting. Asbestos cement can be painted but extreme care must be taken not to loosen or release any dust or fibres. In fact, painting can make the material safer by sealing the surface. If you suspect that the material is straight asbestos rather than asbestos cement, do not touch – call in experts.

Safety and Preparation

When painting ACM you must minimise the risk of releasing fibres that can become airborne. To ensure you protect yourself, your family and those around you (including neighbours and pets) from exposure to potentially dangerous fibres, there are some basic safety rules you should follow:

• Ensure all ACM is in good condition before coating; If the surface is flaking or broken, expert advice should be obtained;
• If the surface needs cleaning, do not power wash, wire brush, sand or scrape the previous surface. It the surface needs cleaning, see the HSE leaflet A12 below;
• Any moss or loose dirt should be washed off with water and the surface left to dry;
• For application of the coating, it is recommended to use a low-pressure spray such as a garden fence spray rather than by brushing. Do not use a high-pressure spray;
• Wear a mask with a particulate filter (and vapour filter if necessary – see paint application instructions), disposable gloves and overalls and eye protection;
• Take care if working at height;
• After painting, check from time to time to ensure the paint is still in good condition and recoat when required.

The Health and Safety Executive has guidance on painting and cleaning asbestos-containing materials at www.hse.gov.uk/asbestos/essentials/:

• EM5. Wetting asbestos materials
• A16. Painting asbestos cement (AC) products;
• A7. Painting undamaged asbestos insulating board (AIB);
• A12. Cleaning weathered asbestos cement (AC) roofing and cladding.

Painting

Apply the paint, preferably by low-pressure spray or roller, following the manufacturer’s instructions.

Panel doors should be painted in the following order:

A. Top edge of door.

B. Side edges of door.

C. Panel moulding.

D. Panel area.

E. Vertical areas between panels.

F. Top horizontal areas over panels.

G. Middle horizontal areas between panels.

H. Bottom horizontal areas under panels.

I. Long vertical on hinge side of door.

J. Long vertical on handle side of door.

Caution should be taken to prevent any runs or drips during the painting of the door, especially on the bottom edges of the panels.

Finally paint the door frame.

For more detail: http://diydata.com/decorating/painting-doors/painting-panel-doors.php

The term 'microporous' is often applied to specialist paints and stains and describes a coating that acts as a barrier to liquid water, but allows water vapour to pass through. The implication being that there is something special about the coating that keeps rainwater out of the substrate, but allows moisture that has found its way into the substrate escape as a vapour. Although almost all coatings will act as a barrier to liquid water, it is not correct to imply that coatings can be made so that moisture vapour can only travel through them in one direction. Moisture vapour will be able to pass through a coating equally well in either direction: from places where there is more moisture, to places where there is less moisture. The rate at which moisture passes through a coating is controlled by the permeability of the coating, the moisture content gradient, the film thickness, and the temperature.

Microporosity is therefore not some miracle technology.

Paints and varnishes are made up of 4 types of components:

• Pigment
• Binder
• Solvent
• Additives

The solvent may be an organic solvent or it may be water. The binder may be dissolved in the solvent, as in a solvent-based gloss paint. Alternatively, the binder may be in the form of an emulsion suspended in water.

The terms solvent-based or water-based are not, strictly speaking, accurate. The coating is not `based’ on water or solvent, but is either dissolved or suspended in it. The terms `water-borne’ and `solvent-borne’ are more accurate descriptions.

Binder can be based on natural oils, such as soya bean oil, which reacts with the oxygen in the air to form a tough durable film.

Solvent-borne products typically contain high levels of Volatile Organic Compound (VOC) and were traditionally for use on wood and metal surfaces, giving a glossy finish but associated with longer drying times and a strong smell. However, water-borne products have typically low levels of VOC and have changed significantly in recent years, with many companies offering a water-borne paint equivalent to a solvent-borne option. The benefits of a water-borne product includes quicker drying times, less smell, and easier cleaning up with brushes and rollers being able to be rinsed with water rather than white spirit (or other proprietary brush cleaners), making the whole decorating process more environmentally friendly.

Washing solvent-borne paint from brushes required the use of white spirit or solvent-borne brush cleaners, which in themselves release VOCs when used, and are difficult to dispose of because of their hazardous nature. Therefore, using water-borne paints, where brushes can be washed in soapy water, can further reduce the environmental impact of decorating.

The BCF has produced an information bulletin on this topic. Read it here.

All hazardous products (not just paints) must be labelled to indicate their hazards. The Classification, Labelling and Packaging Regulation, known as CLP is based on a UN model called the Globally Harmonised System (GHS). Although this establishes some standards, there are options within these. There is also the ability to further add labelling options which means that labels in different countries following the principle of GHS cannot be assumed to comply with UK CLP.

The labelling information may be given as:

For more information on CLP, please visit the HSE website.

As the trade association representing the vehicle refinish paint manufacturers in the UK, the British Coatings Federation is campaigning to combat illegal sales of non-compliant solvent-based basecoats to repair cars, which are in breach of the VOC regulations. In April 2016, a letter was sent to distributors/ bodyshops reminding them of the VOC Paint Product Directive which has now been in place for over ten years. A mystery shopping campaign exercise had also been launched, with one in four VR distributors being visited during 2016 and 2017. See more information here.

Asbestos has not been used in decorative coatings for many decades. However, it may be present in some older films and textured coatings.

Under no circumstances, sand or chip off, or otherwise disturb, the coating, as this will release asbestos fibres.

Paints are not usually tested on animals. However, the chemical substances that are used to make the paint may have been tested on animals due to regulatory requirements.

Paints are complex mixtures of substances. Typically manufacturers will make hundreds or thousands of products. To ascribe the hazards to a product, manufacturers typically follow calculation rules in a legislation known as the Classification, Labelling and Packaging Regulations (CLP). These rules allow manufacturers to take known hazard outcomes of the individual substances in all of the raw materials they purchase and calculate an answer based on logic defined in the legislation. It allows them to define any potential hazards for customers avoiding the need for any animal testing of paints.

Under the REACH Regulation the substances in all the raw materials have to be registered. Before use, conditions for approval are dependant on test data for a defined set of Human Health and Environmental categories. These are based on a United Nations set of criteria. Some of these tests may involve tests on animals. Without this test data the substance would not be approved for use.

Please see our Green Claims Guide here.

Decorative paint manufacturers in the UK have worked on the issue of reducing VOCs in their paints without compromising performance for at least the last 30 years.

One of the key requirements of paint is that it flows out once it is applied to a wall or ceiling and forms a smooth regular paint film, which ensures good durability and resistance properties. This flowing out (coalescing) of the paint is aided by the use of VOCs that may be included in paint formulations. Many modern decorative paints, however, contain no added VOCs.

When VOC legislation was introduced in the UK and across Europe many years ago, the industry responded to the challenge to maintain the required performance of their paint whilst meeting the legal requirements. The results of their efforts are what we have today is VOC-compliant paints for decorating walls and ceilings that are durable and resistant, and meet the needs of the construction industry, whilst also meeting the legislation.

It would therefore not be correct to state that the current low VOC paints are at all inferior to higher VOC paints with regards to durability.

Volatile Organic Compounds are materials which evaporate readily from commonly occurring sources such as vehicle exhausts, cleaning agents, furniture polish and fabric softeners. These also include solvents used in coatings, as well as thinners and brush cleaners.

In the presence of sunlight, these VOCs can react with nitrogen oxides to create ground level ozone and photochemical smogs. These in turn can contribute to pollution of the atmosphere. The UK government and the coatings industry are committed to reducing VOC emissions under international conventions.

Although the impact of household coatings on atmospheric pollution is very small (less than 2% of the total amount of VOCs emitted), manufacturers believe the amount of VOCs in decorative coatings should be reduced and consumers given the choice of using lower VOC-containing products.

Coatings suppliers have introduced a labelling system to inform you of the VOC content of each decorative coating product – a 6-band classification shows the VOC content as Trace; Minimal; Low; Medium; High or Very High.

MIT (methylisothiazolinone) is a preservative and is used in many water-borne paints to give them the shelf-life required for the paint to be transported and stored for sale and use.

MIT is also used in many other consumer goods such as cosmetics, household cleaning products and personal care products. MIT has to be declared by manufacturers when it is present at 0.0015% (15 parts per million); all products containing more than 15ppm of MIT will be labelled with the H317 phrase ‘May cause an allergic skin reaction’, the Signal Word ‘Warning’ and the Exclamation Mark Health Hazard symbol, along with a number of Precautionary Statements.

A very small percentage of the population already sensitised to MIT can suffer an allergic reaction to MIT in paint, and we would advise that they do not apply such products themselves.

We would recommend that consumers always follow the manufacturer’s guidelines for the safe use of paint products. Anyone developing symptoms of an allergic reaction should seek the advice of a medical expert.

(Decorative: Trade and DIY painting only)

Preparation required varies according to the surface to be painted but note that preparation is the key to a successful outcome of any decorating task and it may well take longer than the painting of the area itself.

New plaster should always be allowed to dry thoroughly before it is decorated, unless you are using an emulsion paint specifically for new plaster. As the plaster dries it will change colour from dark to pale pink, and when it is dry any solids which appear on the plaster should be removed (a cloth such as hessian is ideal for this). Before applying the first coat of emulsion, a primer is required and usually the emulsion can be diluted (as per the manufacturers’ instructions) to act as a primer.

If old plaster is clean, dry and sound, no special preparation is required. However if the surface shows evidence of old distemper residue or is powdery, it should be sealed with a stabilising solution.

Surfaces previously finished in matt emulsion paint and in sound condition merely require washing with a sugar soap solution which is thoroughly rinsed off. Silk or satin emulsion paints and gloss and traditional eggshell finishes, in addition, will require wet rubbing down to provide a key for the new paint.

With any of the above surfaces, any loose or flaking paint should be removed and sanded and noticeable cracks should be made good, by use of a filler, and the area primed before painting.

To prepare wood, lightly abrade the surface using a dry sandpaper, rubbing in the direction of the grain. Dust off with a damp rag and allow to dry.

Remember to take adequate precautions when preparing surfaces, especially in relation to dust inhalation.

Exterior wood, in particular, might be rotting or damp in which case it will need to be repaired and dried out prior to any painting.

When painting over existing wallpaper, a successful finish will only be obtained if the paper is sound and adhering firmly, especially at the edges and joins. If the wallpaper is damaged or peeling or loose in any way it is recommended that it is removed. However this might lead to extra work due to the condition of the walls which might have crumbling or damaged plaster.

If the wallpaper is in good sound condition it will need to be wiped clean prior to painting. Vinyl coated wallpaper will require scoring and a primer before application of an emulsion paint to ensure good adhesion.

If painting over dark coloured wallpaper, the colours (particularly reds) are liable to bleed and should be treated with a thin coating of stain sealer first. Metallic inks will eventually cause a discolouration of the paint film due to dirt retention on the colder metallic area.

In 2010 the new solvent emission limits (VOC or Volatile Organic Compounds) for all decorative coatings for wood and metal came into force and manufacturers adjusted their formulations to comply with the European Regulations. This resulted in lower solvent products coming onto the market.

There were complaints at the time that some of these new solvent-borne paints for wood and metal were more prone to discolouration. This discolouration was seen to occur in certain instances, such as in low levels of natural daylight or where fumes from other materials (e.g. carpet adhesives, floor levelling compounds) were present and this was of concern to manufacturers as this was not displayed during the development of these new coatings.

Paint manufacturers addressed the problem at the time by reformulating the impacted paints and are now confident that the performance and finish of all these paints are comparable to the versions that were produced prior to the legislation changes coming into effect.

All solvent-based paints for wood and metal discolour over time to some degree. Customers who want whiteness which will not discolour should use a water-based paint.

If the surface to be painted has been well prepared (see "Surface Preparation”) and paint is applied as directed, it is likely that repainting will not be necessary for several years. Coatings subjected to extreme weather conditions may need more frequent attention.

However, if a surface has not been sufficiently prepared, some problems may occur:

Cracking occurs when the top coat of paint is unable to expand to the same degree as the previous coating. This occurs commonly when an undercoat has not been given sufficient time to dry, or indeed if a paint is encouraged to dry too quickly, for example by increasing the temperature in a room or if decorating exterior surfaces in excessive heat. Cracking will also occur if wallpaper adhesive is allowed to dry on new paintwork.

Mould can appear as multi-coloured spots or patches, and growth of mould is encouraged by dampness and poor ventilation. It may also appear where paint has been applied to wallcoverings laid using unprotected paste – all wallpaper adhesives now contain fungicides to minimise the risk of mould growth.

It is certainly not worth simply painting over any mould patches as the patches will reappear. The cause of the dampness needs to be found and treated, and then sterilised either using a fungicidal solution or a 3:1 mixture of water and household bleach. It is then important to leave the area for at least a week to check for any reappearance of mould before repainting. It is then advisable to coat with a paint containing a fungicide. Remember to avoid splashes of fungicide on the skin and accidental consumption by children and animals.

Specialist products are available to treat the effects of damp. These act as a barrier to limit the risk of new decoration being spoilt.

Peeling or flaking can occur when the underlying surface has not been sufficiently prepared (see "How do I prepare the surface prior to painting?"), if dust or dirt particles remain on the surface or if the surface is still damp or unstable, or if rust is forming under the paint surface. As with cissing (see below), peeling may also occur if paint has been applied on a very shiny surface. Shiny surfaces may be lightly sanded prior to application of paint.

Chalking is the appearance of a powdery deposit on the surface of dry paint. It occurs most commonly when paints manufactured for use on interior surfaces are used on exterior surfaces, when paints have been over-thinned causing a deficiency in binder, or when paints have been applied before a surface has been sufficiently sealed, e.g. on new plaster. Remember to always choose the correct paint for the surface being painted and to always follow the instructions on the tin.

Blistering is when a paint or varnish forms bubbles on the surface. This could be due to too much paint being applied in one go, moisture trapped in the underlying plaster, using non-heat-resistant paints near sources of extreme heat. Blistering can also occur if an underlying wallpaper has not been hung using sufficient adhesive as the addition of a coat of paint could cause it to ‘bubble’ (remember though that if painting over lining paper, blistering that appears within a few minutes of painting usually flattens out during the drying process). To rectify, the blistered paint must be removed, and the surface made clean and dry prior to repainting with an appropriate paint, either one that is permeable (where damp) or heat-resistant if required.

Cissing is when the paint fails to form a continuous film on the surface, peeling back when it is applied leaving small round bare patches. This is due to painting either a greasy or oily surface, or painting very smooth and shiny surfaces. It can occur when emulsion paint is applied over oil-based paints, regardless of gloss.

The surface should be thoroughly washed with sugar soap and rinsed, and shiny surfaces may be sanded lightly prior to applying paint.

Please note that as a trade body representing the manufacturers of paints and coatings, our expertise is in providing technical and regulatory advice to the manufacturers (for instance on the formulation of their coatings). We don’t have the competence to provide technical advice on how to solve technical challenges around paint repairs/paint problems. We’d suggest contacting the Painting and Decorating Association, who may be able to help provide some guidance, and/or advise of a professional painter/decorator in your area. If you have a complaint about a specific paint that you’ve used, please visit the Help desk support for non members.

‘Wall odour’ is a problem that occasionally occurs when an unpleasant ‘tom cat’ like smell is noticed a few days or more after painting. There have been occasional reports of this effect over several years from the UK, Europe, USA and Australia, affecting a very small number of users.

The BCF has been in discussion with industry experts about the problem. Research indicates that it is likely to have been caused by certain ingredients in the freshly dried paint reacting with ozone in the air, especially on hot sunny days when windows are often open, this releases very low levels of some extremely smelly materials, which are very similar to cat pheromones, hence the tom cat odour.

In view of our knowledge of the constituents of paint and the cause of the odour and the levels involved, we are confident that there are no health and safety risks. The materials involved do produce an extremely strong smell, even at very low levels, hence people’s alarm.

It can be prevented or rectified by applying an alkali resisting sealer to the wall before painting. Please consult with the manufacturer of the paint that you purchased for more advice on this.

If an independent on-site inspection is required, the following organisations may help in providing this service;

Independent test houses

NOTE: A full list of accredited laboratories, inspection and certification bodies can be found by going to www.ukas.com

Find a list of testing companies here.

A number of Associate members provide SDS and labelling authoring - the full list together with contact details can be found here by scrolling to 'Directory' at the bottom of the page.

There are many other companies providing chemical management software especially in relation to SDS and labelling authoring. As a useful starting point, there is a guide from Chemical Watch, now called Enhesa which is free of charge and available from here: Chemicals Management Software Guide (chemicalwatch.com). There will also be other software providers that you can use, and an online search will be able to provide you with some more companies.