Intumescent Fire Protection – Project Considerations

In this in-depth blog by company director Conor Smith, Central Counties Painters and Decorators consider the key factors in applying intumescent paint to structural steelwork, including considerations for both the client and the applicator.

The key factors affecting successful application are as follows, which I will go in to discuss in further detail:

  1. Environment Considerations
  2. Project Requirements
  3. Planning
  4. Application
  5. Inspecting


The conditions within which you apply the coating are critical to success. The first consideration is exposure to the external environment. Typical influencing factors are whether the building is water tight and the time of year the application is taking place. In the winter you will come up against barriers such as temperature constraints, moisture level and site conditions. These factors are then either amplified or softened by the stage of construction.

As with most paints, intumescent coatings have an ideal application temperature along with maximum and minimum temperature conditions required for successful application. What impact will temperature delays have on your construction schedule? Is the building water tight? More often than not, a minimal degree of weather protection will be considered ample to commence intumescent work, however if you are using a water based coating, any leaks still located in the building will damage the coating, and void its protective ability. This will lead to remedial work and increased costs. Similarly, will the presence of water prevent application in the first place, weather it is morning dew typical of spring, or ice typical of winter. These impacts all culminating can have a severe impact on competitively priced projects.

The finished building environment also impacts specification – building environments from C1 (dry)-C5 (wet) will all require differing specifications to function effectively during their lifespan. Contractors self-specifying projects should ensure that their material supplier is fully furnished with all aspects of the working environments in which the area will function. Steelwork in swimming pools will have significantly different performance requirements to those above an office.

Project Requirements

Each project can hold unique details which cause them to differ to each other. The most frequent of which is programme requirements, but other factors include the finish required, accessibility, material specifications and design. The project programme can throw up a number of factors to consider, especially when considering pricing and profitability. If the main contractor/client have programmed the works tightly with other trades, who will subsequently be fixing items such as M&E or similar equipment to the structural steel, or working below you installing concrete floors or screeding, will this have knock on implications to your ability to complete the works in an efficient method. With respect to programme, often applicators will find they are at the back of a queue of trades waiting to commence or finish their trade package. M&E installation is the number one factor in a main contractors profit, so often the M&E Contractor is given free range and prioritised access, especially on tightly scheduled projects. In this situation, if the M&E works are prioritised as a result of delays (usually the case) what impact will this have to you as an applicator. Increased likelihood of masking and protection requirements, increased difficulty in accessing surfaces due to cable trays and later on due to suspended ceiling fixings.

Other trades also pose issues, access implications in terms of working at height equipment which you have planned to utilise. An example could be that where a delay has knocked back the application programme, the installation of finished items such as exposed M&E, glazing, screeding or raised access flooring, would increase the degree of masking and protection you are required to undertake as well as limit your access to areas and what access equipment you use. Will the client agree to these increased costs or will you be expected to absorb the effects of delays (most likely the latter!). My advice is get in as early as possible in order to avoid conflicts and maintain your profit margin.


Planning leads conveniently on from the previous consideration above. Bearing in mind the project considerations, ensure that your client is aware of the factors which will lead to cost increases in order that they are avoided. Cost increases are the blight of most projects whether large or small, and it is your job as the applicator to work with your client to avoid these wear possible. If main contractors were experts in each trade the utilised on site, they would not need to employ specialist sub-contractors.

Whenever we start a contract, our first thought when considering the application stage is to plan each area of the contract, identify bottlenecks in the programme and try to get ahead of them. This is in the applicators interest as it will help maintain or improve your bottom line. The major factors to consider are as follows: Health and safety, access and equipment, material requirements, labour requirements and future obstacles.

As a minimum I would always make sure the following is in place prior to commencement of a contract. Adequately experienced trades, RAMS, COSHH Assessment, Availability of COSHH datasheets, relevant inspection and set up of access equipment. PAT testing to electrical tools, PUWER and LOLER inspections, material specification and a detailed plan of thicknesses for each steel being applied to, suitable quantities of materials, suitable storage location for materials and an awareness of the project programme with deadlines and milestones identified.


Selecting the right tools for the job is essential. This will vary from job to job depending on the nature of the works. The key influencing factors for airless spray application would be tip size, filter and accessories, power availability, cleaning facilities, material and equipment storage facility. Other key factors include whether to apply the coating on site or off site, what protection requirements are needed for surrounding surfaces, having experience of the material you are using and enough material to get the job done.


This part of the blog is a plea to clients and main contractors. As a painting contractor undertaking decorative works on a project, I have far too often seen intumescent coatings on steelwork which do not meet the specified standard. The most typical example would be bolts and fixings.

Based on what I have seen and discussions I have had with manufacturer representatives, I would highlight the below items as the most typical infringements against specification requirements:

  1. Un-primed fixing bolts being sprayed with intumescent.
  2. Spray application over rusting steel.
  3. Inadequate dry film thickness of coatings.
  4. No top seal applied to exposed steelwork.
  5. No quality assurance process undertaken in any degree by contractors/ clients or manufacturers on small scale projects.

Fire protection of steelwork is one of the last ditch attempts to save lives when a building is on fire. Out of every 1000 buildings constructed and intumescent applied, there may be one fire where the intumescent plays a role in saving people’s lives. This low statistical risk has led to complacency in application and inspection where intumescent is not a critical aspect of building control, i.e 10-50 storey steel framed buildings. But the ironic part is that one omission in application in the one building the does burn to the ground could result in an unnecessary death. Intumescent application should be treated with the same degree of severity as the commissioning of the fire exit lighting or a sprinkler system, as it could have the same influence in ensuring people escape during a fire.

My grievance with the above is not that these factors occur because often it can be through human error; my grievance is that it undermines the entire process of the application and there is only a small percentage of standard construction projects that are inspected thoroughly. Without independent inspection and monitoring, or applicator guarantees, the risk application defect remains.