Fire retardant paint and varnish

Fire retardant paints are an important element of passive fire protection because they can be applied to various combustible building materials to bring them into line with fire regulations.

A fire-retardant paint reacts and swells when a temperature of 120°C is reached or exceeded. This process releases water vapour from the coating (paint or varnish) and creates a soft cooling effect on the surface. This creates an insulation effect and reduces heat transfer.

lWhat types of substrates can be protected with fire-retardant paint.

Structural steel and cast iron

In the event of fire, the load-bearing capacity of steel construction elements can be seriously affected. The structure may then collapse, obstructing evacuation and fire-fighting and endangering personnel.

The duration of protection during a fire often varies depending on the manufacturer and individual product, but is usually between 60 and 120 minutes. During this period, the load-bearing capacity of steel must not be impaired.

Wooden surfaces

A range of wooden surfaces can be coated with fire retardant paint to meet fire standards. The wood elements that can be protected are for example: frames, stairs, floors, ceilings, cladding, doors etc.

Two standards apply to wooden substrates, and these look at both fire resistance and flame retardancy.

Fire resistance

The legal fire-retardant standards require a wood substrate to maintain its structural or compartmentalisation capacity for 30 or 60 minutes. Conformity is determined by a fire test, which must show how long a fire retardant swelling paint on a particular wood product can maintain the integrity of the product. Account is also taken of the burning rate of wooden substrates (the rate of charring). Put simply, low density softwood burns faster than high density hardwood, and this means that a structure with softer wood must be much thicker to achieve results comparable to hardwood.

Flame retardancy (Resistanceof the surface to the spread of flames)

This regulation is aimed at the ability to prevent flames from spreading over the surface of a substrate.

There are two different approaches to this classification:

– Class 0 & class 1 – according to the European classification.

Normal construction timber can obtain a better fire class with this technique, such as B s2 d0.

Plasterboard and Plaster

With a fire retardant coating system, existing plasterboard and plaster ceilings/walls can also be upgraded to a fire resistance of 30 or 60 minutes. This is particularly useful for inherited property where the properties must be preserved and no alternative method of compartmentalisation is permitted.


Fire-retardant and exhilarating paint can also extend the fire resistance of concrete structures such as office buildings, car parks and tunnels.

There seems to be a popular belief that concrete is fire-resistant indefinitely, but this is not true. When exposed to rapid fire (such as in tunnels or car parks), concrete may lose its fire resistance due to splashing. This can lead to direct exposure of the reinforcement and then to the failure of the structure.

Fire retardant varnish

Wood can be treated with a varnish. The application and the result are similar to paint. Fire retardant varnishes are technical products and cannot be compared to a standard varnish. As with paint, the necessary amount depends on the type of wood or construction part. Also with varnish you can obtain a fire class B s2 d0. Various types of wood and construction components were tested by Fire-Proof with fire-retardant varnishes.

The choice of paint and varnish has an impact on the final fire class of the wooden construction, depending on the type of wood. Do not hesitate to contact us to find the ideal construction and fire retardant solution.


The type of fire-retardant paint or varnish and the quantity required is determined on the basis of the type of wood or construction part. Fire retardant paint on wood is normally white. A protective finishing coat can also be chosen in a RAL colour of your choice. The paint can be applied with the roller or with an airless sprayer, depending on the circumstances.

Aarzel niet om contact met ons op te nemen als u vragen heeft.

We can offer you different types of fire-retardant paints and varnishes according to your needs. We can offer you different types of fire-retardant paints and varnishes according to your needs.

Tel: +32 (3) 281.69.94