Home » Workplace & Commercial » Fire Protection » Intumescent paint colours and getting a good finish on steel

Intumescent paint colours and getting a good finish on steel

Intumescent paints are fantastic for fire safety, as they help to protect the surface below. Additionally, intumescent paints can be used to achieve fantastic decorative finishes on steelwork. There are different finishes available to use on steel, depending on your desired look.

Viewing on mobile and know what you need? Shop the range here.

Painting Structural Steelwork

How to get a good finish using intumescent paint on steel


If you start with a quality intumescent paint, you’ll be able to achieve different finishes that also help with fire safety. A thin-film, waterborne Intumescent paint should allow you to achieve 30 to 60 minutes fire resistance easily in only a few coats. Use a compatible anti-corrosion primer then coat the steel with intumescent paint. This will often leave you with a smart matt finish. At this point you can leave the steel and coating as is if it can be guaranteed that subsequent in-service conditions will be in a C1 environment as defined in ISO 12944-2:1998. If not then a topcoat will be required which can be supplied in virtually any colour and finish.


A gloss finish is often a popular choice, as the shine works well on steel elements. It’s also an easy clean, hardwearing finish. Use an approved topcoat for the intumescent paint you’ve chosen to make sure you meet fire safety regulations.


An acrylic eggshell finish can also help you to achieve an approved Class 0 finish, in combination with the intumescent base coat. This will give you a mid-sheen finish that can be wiped clean like gloss paint. It’s a more subtle sheen than gloss paint, if a gloss finish is too high-shine for your project.


Again, a vinyl matt finish can be achieved, and is becoming increasingly popular. If you are not looking for a shiny finish, a matt finish be a compromise as it won’t be as hard wearing or as easy to clean so may require more maintenance over time. Matt paints are often a good choice for surfaces with many imperfections as a matt paint will not draw attention to them, a gloss paint may highlight imperfections.

Bollom Flameguard Ultra Gloss

Shop Now


Bollom Flameguard Ultra Acrylic Eggshell

Shop Now


Bollom Flameguard Ultra Vinyl Matt

Shop Now


Top tips

  • To ensure your painted steelwork looks as good as it performs, take care applying the paints and for the smoothest finish apply multiple thinner coats rather than a few thick ones.
  • Make sure to clean and prepare surfaces as instructed before applying primer and coatings. Getting good adhesion to the substrate and between coats is important as it needs to be able to perform effectively during a fire.
  • Remember to carefully cover any areas you do not want to be painted.
  • Use an airless sprayer to help you achieve an even, professional finish for larger projects.
  • Finally, don’t forget to speak to your Building Regulations Officer to make sure your property is in line with any relevant regulations.

Related Articles: Find out more about exciting industrial paint colours that are outside of the norm.


  1. Hi,

    My name is Guy and I work in My Construction.
    In my site we use some “L” shape aluminium profiles for stabilizing glass fixed windows.
    The aluminium has its fire rate as below, my question to you if you think we should coat it with Intumescent paint?

    Aluminium, aluminium to BS 1474:1987 Alloy 6063-T6.
    AA Fire rated to surface spread of flame to BS 476: Part 7: 1997

    • Hi Guy,

      Thanks for your question.

      We wouldn’t be able to advise on increasing the fire protection of the aluminium or not, you would need to turn to your relevant authority on this project for guidance on this.

      I’m afraid we don’t stock an intumescent paint that can be applied to aluminium to increase the level of fire protection either.


  2. Is it possible to add colouring to intermesent Paint so you can be sure you not missing any spots when doing second or 3rd coats ??

    • Hi Bobby,

      No, we cannot recommend adding colouring to intumescent paints. We have tintable topcoats available for use over intumescent layers, but the intumescent paint itself shouldn’t be modified. If you require more information about our fire products then please contact our technical support team on 0113 2455450 (option 2) or send a message to [email protected].

  3. Do I need to galvanise steel that needs to be treated with intumescent paint?
    In other words, does the intumescent paint offer any anti corrosion properties or protection to the steel.
    The structural steel in in a Whiskey Distillery.

    • Hi Liam,

      Thank you very much for your question. Intumescent paint provides no corrosion protection and therefore must be applied over a compatible anti-corrosive primer.

      Steel could be galvanised before an intumescent paint is applied but there would be further preparation required such as degreasing, applying a mordant solution to passivate the galvanised surface and then a protective primer applied first.

      If the steel is not in an external environment, then 9 times out of 10 it will not be galvanised before the system is applied.

      I hope that helps, and feel free to get in touch if you have any further questions.

      Many thanks

Leave a Reply

Your email address will not be published. Required fields are marked *