Selection, Application & Maintenance of Fireproofing Coatings
Protection from fire is no longer optional for today’s industrial and commercial construction sectors. In different countries around the world, it is now a legal and moral requirement. With continuously tightening safety standards and building codes, fireproofing coatings are considered to be highly effective passive protection systems for steel and concrete structures. When these coatings are selected, applied, and maintained properly, they not only preserve critical assets during fire incidents but also save lives.
Understanding Fireproofing Coatings
Also known as fire-resistant paints or intumescent coatings, fireproofing coatings are designed to delay structural failure in the event of a fire. When these coatings are exposed to high temperatures, they reduce heat transfer to the substrate beneath by expanding and forming an insulating char layer.
There are two major categories of fireproofing coatings. Intumescent or thin-film coatings are used commonly in commercial and architectural steel structures. When exposed to heat, they swell up to 50 times their original thickness to form a carbonaceous char barrier. On the other hand, cementitious or thick-film coatings are used mostly in heavy industrial or hydrocarbon environments. These coatings resist high heat and mechanical damage by forming a dense insulating layer.
Why is Fireproofing Important?
50% of steel’s load-bearing capacity is lost at around 550°C. It takes just a few minutes to reach this temperature in large fires. Therefore, a structure can collapse in no time without adequate protection.
Functioning as the first line of defence, these coatings ensure that the structure retains its strength long enough to prevent or delay collapse. In Australia, to meet fire safety performance criteria, it is essential for organisations to comply with AS 4100 (Steel Structures) and AS 1530 (Fire Tests) standards.
In addition to industrial safety, fireproofing coatings are also critical for reducing asset downtime, meeting compliance and insurance requirements, and protecting key infrastructure like bridges, refineries, processing plants, and tunnels.
How to Choose the Right Fireproofing System
Selection of the right fireproofing system depends on different important factors such as environment, building type, substrate, and fire-rating requirement.
- Weather-resistant systems are required for outdoor installations, particularly in chemical and coastal environments. For petrochemical facilities or offshore oil platforms, epoxy-based intumescent coatings are ideal because of their durability and chemical resistance.
- The response to heat is different for concrete, steel, and composite structures. For example, concrete needs coatings capable of resisting spalling, while steel requires protection against rapid temperature rise.
- Fire resistance levels (FRLs) are typically defined as 30, 60, 90, or 120 minutes. Any coating system must be in accordance with the structural fire protection rating required by the design specification.
- The choice between trowel-applied and spray-applied coatings depends on project scale and site logistics. Thin-film coatings are often preferred because of their smoother finishes and faster installation.
Application Best Practices
If they are not applied properly, even the best coatings can fail. Successful fireproofing is all about correct surface preparation, mixing, and application procedures.
- Coating adhesion requires clean, degreased, and grit-blasted surfaces.
- A compatible primer should also be used.
- Coatings must be applied under controlled temperature, humidity, and ventilation.
- During each stage of application, visual inspections, adhesion tests, and thickness checks (DFT) should be carried out.
Periodic Maintenance
Though fireproofing systems are durable, they are not maintenance-free. To ensure that they remain effective throughout their service life, these systems require regular inspection.
- Routine checks for delamination, impact damage, or cracks, particularly after maintenance work or equipment replacement.
- Check for degraded topcoats resulting from chemical exposure, moisture ingress, or exposure to UV radiation.
- Depending on exposure conditions, the topcoat may be need rework every few years.
- Inspection logs and test reports must be maintained properly for regulatory compliance and insurance purposes.
If you want to find out more about fireproofing coating systems, please contact our experts at Coating Management Solutions.