We’ve spoken before (probably at length) about the prevalence of Steel as the world’s most critical designing, engineering and construction material. So, it is not our intention to dwell on this overly today. What we want to discuss is a more comprehensive overview of the importance of protecting steel to ensure that in the case of fire, it maintains its structural strength.
The protection of steel, a need for greener building options and more radical architectural designs mean the building and engineering sector has progressively embraced the utilisation of thin-film intumescent coatings, designed for the specific purpose of protecting the structural elements in the case of fire and looking good at the times there is not.
As we’ve discussed before, low-density fibre or cementitious compounds were used traditionally to protect structural steel. When sprayed on steel, this coating type provides heat resistance and can be applied relatively easily by designated applicators. The determination of approved thickness is determined by the type of steel, the thickness and the purpose of the steel as dictated by building and construction codes, with the sprays divided into wet or dry materials thickness gauges. Under normal circumstances the coatings are inert but when they are subjected to extreme temperatures such as a building fire, they undergo a chemical reaction and expand significantly as compared to the original thickness. They then develop a thick char giving superior fire resistance by creating a buffer between the fire and the steel members, before the temperatures become adequately hot to affect the integrity of the steel.
The new breed of intumescent
As has been discussed before, low-density fibre or cementitious compounds are the old-guard of steel fire protection, where thin-film intumescents (such as Aithon for Timber and Nullifire for steel) are the new guard. These newer technologies offer multiple advantages as an option for fire protection:
- The do not adjust the characteristic properties of materials, for instance, the mechanical properties;
- They are easily processed and handled;
- They can be applied on-site or off-site thus giving increased options to building timelines;
- Different kinds of intumescent paint can be utilized on an assortment of construction materials, for example, steel, woods, composite components and concrete.
When aesthetics are an integral factor especially with steel that is exposed to the general public, intumescent coatings are a great solution. The product is applied much the same as paint (albeit by trained professionals), with each layer adding to the general thickness of the product, and thus the fire protective capabilities.
Light-weight steel walls and fire protection
In the construction industry, light steel is commonly used for frame walls which are mostly non-load bearing applications. Made with studs and tracks, these light steel framed walls often abut to structural, load bearing elements. In this instance many builders look to use cementitious fire boards to protect the structure. However, a suitable option would be to consider use of Nullifire SC902 where the steel has been galvanised. Plasterboard sheeting can then be used over the top of it as a finishing product.
Fire protection for Oil Industry
Whilst Permax do not offer fire protection options for the petro-chemical industry, it is an important segment which we should cover off as part of our overview of steel protection. These industries handle oil-based chemicals which burn much faster and much hotter than traditional cellulosic (typical house and building fires) making the need to protect the steel more important than ever so as to ensure crews working in the factory (or on the oil rig) have the ability to safely evacuate without fear of the structure tumbling around them.
Epoxy coatings have been utilised effectively for quite a long time to give corrosion protection and fire protection in challenging environmental conditions, typically off-shore applications and the petrochemical industry on shore. When carefully applied and rigorously maintained suitable protection can be achieved for as 25 years or more. Such coatings, combining strength/durability, corrosion resistance and fire protection have prompted the wide use of fire resistant applications in the petrochemical, offshore and marine industry.
Overall, due to continued improvement in formulation, application and performance intumescent coatings have become more accepted and more commonly used in recent years and are likely to only increase in use. This is being driven by the fact that thin-film intumescents, over and above providing fire protection, they offer a variety of versatile, durable, attractive, low thickness and low weight coatings for a wide variety of structures. For more information about passive fire protection, speak to one of the specialists at Permax now.
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Permax constantly update the documentations based on the new fire testing outcomes and change of standards and regulations. To ensure the documents you read are up-to-date, please contact the Permax technical team.