Fire Protection for Structural Steel
CLM Fireproofing are the UK's foremost providers of spray on fireproofing, fire protection drylining and boarding for steel beams. We combine the latest technology with years of experience and a dedication to best practice. Our work in steel fire protection utilises a variety of measures within a wider passive fire protection strategy, helping clients comply fully with safety regulations and industry standards.
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Industry Leaders in Steel Fire Protection
All of our work is guided by a specialist knowledge of how steel is affected by fire damage. Depending on the severity of conditions, a structural fire can exceed temperatures of 800°C or higher. Temperatures of around 550°C will cause a decline in the load-bearing properties of structural steel. Unprotected steel frames can resist fire for approximately 15 minutes. Our team of installers offer a range of solutions to increase minimum periods of resistance, in line with industry fireproofing requirements for structural steel.
Intumescent Paint Application for Steel
Intumescent paint contains thermodynamic compounds which will expand into a solid, carbonaceous layer when subjected to temperatures of around 250°, creating a protective coating around steel beams and other structural elements. This then increases the structure’s fire resistance rating, which is usually either between 30, 60 and 90 mins. By reinforcing steel structures with intumescent coatings, we maximise the time taken by emergency responders to extinguish flames and evacuate buildings safely.
When embarking on a project, we consider a variety of factors such as timescales, environmental conditions and basic functionalities such as acoustic insulation. We are also able to recommend intumescent coatings for projects where aesthetics are a priority, especially when steel is exposed to the general public.
There are several ways to apply intumescent products within a structural fire protection strategy. CLM Fireproofing will select the ideal product for client’s specific requirements, based on factors such as project specification, environmental conditions, the current phase of ongoing construction projects and finally aesthetic expectations.
Our team is also able to apply intumescent coatings both onsite and offsite. This allows us to enact the strictest possible standards of quality control, so clients can be certain that their projects comply fully with building regulations.
Cementitious Fireproofing
Cementitious fire protection provides fire resistance to various structural building elements. Our teams apply cementitious coatings in multiple layers, forming a robust barrier. Once applied, this non-reactive coating reduces heat transfer and offers protection to the structure in the event of a fire.
Applying cementitious fireproofing for steel
Cementitious coatings are applied via trowel or spray. There are commercial benefits to applying cementitious coatings compared to other products such as intumescent paint. Firstly, surfaces often do not need to be prepared for the application of cementitious materials. This reduces the cost and waste traditionally associated with methods such as shot blasting. As well as this, once the desired thickness of the cementitious materials has been determined, the application process is quick and effective.
Our team of specialists can apply cementitious fire protection as part of a wider passive fire protection package. They will always work with the utmost professionalism and compliance with the latest fire protection regulations. The protection applied can also be followed with an aesthetic finish, if desired, either trowelled, profiled or boxed.
Intumescent Fire Board Systems
Our team is well-versed in offering enhanced fire protection for structural steelwork. This includes the installation of rigid and semi-rigid boards, encasing steelwork for additional fire resistance across various external conditions.
By helping the steel to maintain its structural integrity and loadbearing capacity when exposed to critical temperatures, board systems can lengthen the time available for a building to be safely evacuated. Fireboarding offers an array of additional benefits, as well as protecting structural steel from fire damage. These include increased thermal insulation, enhanced acoustics and additional moisture resistance. Furthermore, many fire boarding systems are relatively lightweight which makes installations easier, although we would always recommend checking product specifications with manufacturers prior to installation.
With our level of industry expertise, we can deliver simple, quick and effective installation and board replacement across compartment walls, floors and ceilings. Our team can also provide film intumescent coating systems with attractive surface finishes, which are sure to please clients, tenants and project stakeholders alike.
Professional Drylining Service
Drylining systems are a fixture in many commercial and residential buildings. They usually consist of metal-framed partitions, which our team can install in compartment walls to meet various functional requirements, including fire protection, improved acoustic performance and thermal insulation. Drylining can also revert a site back to its original state following the completion of a fire stopping project.
Fully Accredited Fire Protection Experts
When working with CLM Fireproofing, clients can have confidence that their projects will be delivered in full compliance with structural fire standards. In addition, our years of experience managing complex projects ensure that works will be completed on time and within budget.
OneTrace
Central to our operations is OneTrace, an innovative compliance management software that allows for the meticulous recording and tracking of projects in real time.
Our operations and management teams are equipped with OneTrace-enabled smart devices which are used to log on-site/mobile installations, as well as all Health and Safety forms. Every client is issued with a unique login that allows them to view project progress, and access verified documentation to fully comply with current fireproofing regulations.
Frequently Asked Questions
How does fire affect the yield temperature of structural steel?
Structural steel can withstand approximately 425°C before it begins to soften. Between 600°C and 650°C, the steel will lose half of its strength and will pose a risk of failing (depending on the load it bears). Unsurprisingly, even a house fire will reach very high temperatures of around 600°C or just under. Of course, it depends on what the material being combusted is. A simple candle will often burn at 600°C or more, whilst propane can cause a fire to reach almost 2000°C.
How is the fire resistance of steel calculated?
Fire resistance is calculated using three main criteria, all of which are integral to limiting the risk of fire damage to a building. A structural element or product’s ‘fire resistance period’ is dependent on the time (measured in minutes) it takes for any of the below criteria to be compromised.
- Load-bearing capacity – whether or not the steel can support a required load without collapsing
- Integrity – the steel’s ability to prevent the passage of heat, flames and smoke
- Insulation – the steel’s capability to withstand exposure to rising temperature
What are the industry regulations for the fire resistance of steel?
Standards for the fire resistance of steel are set by two main pieces of legislation: Fire safety: Approved Document B, which is generally accepted as the main set of regulations for passive fire protection and BS 9999 which are the requirements set by the British Standards Institution for fire safety in the design, management and use of buildings.
Approved Document B provides a range of guidelines on minimum periods of structural fire resistance, primarily for multi-storey non-residential buildings:
- An office building that is up to 30m in height (and does not have a sprinkler system) has a minimum fire resistance period of 90 minutes
- A commercial building (such as a shop) that is up to 19m in above-ground height has a minimum fire resistance period of 60 minutes.
BS 9999 was published in 2008 and offers a more flexible and holistic approach to codes of practice in comparison to Approved Document B. This approach aims to accommodate as many factors as possible, no matter how small, such as the size of fire doors or new fire protection technologies like mist suppression systems. While BS 9999 is not meant to act as an oppositional approach to Approved Document B, it acknowledges that each building has a unique ‘risk profile’ based on occupancy, ventilation and an array of other circumstances.
While the above regulations do not mention steel directly in their specifications for fire resistance, they provide ample context for contractors, managers and site teams to decide on the most effective solution for structural steel fire protection.
What is the melting point of structural steel?
The lowest point at which carbon steel will melt is 1130°C, though 0% carbon steel won’t melt until 1492°C. Regardless of the type of steel, it will usually be completely liquid by approximately 1550°C.
What are the regulations for protecting steel structures from fire damage?
Buildings must be designed so that their stability can be maintained for a reasonable period in the case of a fire. Structural steel is a load-bearing component in most buildings. Therefore, complying with guidelines for structural steel is crucial for maintaining a building’s overall stability. For England, Scotland and Wales the main legislation is Requirement B3 in Approved Document B Fire Safety whereas for Northern Ireland it is Technical Booklet E, 2012.
Should I use water-based or solvent-based intumescent coatings?
Applying water-based intumescent paint for steel beams can be time-consuming due to the number of required coats and the total dry film build needed to provide adequate fire protection. What’s more, water-based intumescent paints also suffer from poor water resistance, which limits their application in indoor spaces and areas that require a waterproof topcoat. Conversely, solvent-based coatings are generally used on semi-exposed steel due to their ability to withstand various weather conditions. They also offer the added benefit of drying faster and leaving a smoother finish.
What’s the difference between thin film and thick film coatings?
As their name suggests, what differentiates thick film and thin film coatings is that thick film coatings are much denser. They also have a lower expansion rate, a ratio of around 5:1 compared to thin film coatings which expand at a rate of approximately 50:1. Thin film coatings are usually the industry standard as they are suitable for buildings where fire resistance regulations (specified by Approved Document B) are either 30, 60 or 90 mins. Conversely, thick film coatings are mostly used in industries that require working with extreme temperatures such as the petroleum industry. Finally, in comparison to their thinner counterparts, thick film coatings are often used in projects that require intumescent coatings to have a decorative finish.
Should intumescent coatings be applied on-site or off-site?
There are various benefits associated with applying intumescent coatings both on-site and off-site. For example, with on-site applications there is no need for large or complex spray equipment, and all the steel that needs to be coated is already erected and in place. Finally, on-site application is not a ‘wet-trade’, so construction activities are not delayed while waiting for access to floors.
In comparison, the off-site application of intumescent paint can save time in the construction schedule, as it means that trades do not have to spend days moving through floors and applying paint on-site. After the steel has been erected, there is a shorter window in which applicators are required to be on-site to resolve any damages or spray steel connections. Additional benefits include a reduced number of on-site trades, fewer delays in accessing work sites due to extraneous circumstances, and improved application productivity as time is not spent on moving equipment, personnel or products.
How does intumescent paint protect steel?
Intumescent paint protects structural steel by lengthening the time it takes for steel to reach its ‘critical temperature’. Critical temperature can vary based on the building design. While it has been known to range between 350° – 750° in Britain it is commonly 550°. Once steel reaches its critical temperature, it will begin to lose its nominal integrity and load-bearing capacity, increasing the likelihood of structural collapse.
In the event of a fire, the chemical properties of intumescent paints or sealants undergo an endothermic process. This means that when temperatures reach around 250°, the paint will expand into a carbonaceous char layer. Once solidified, this forms a protective coating for steel beams, columns and other building elements, without affecting their mechanical properties or basic functionalities. This increases the steel’s fire resistance time whilst the building is evacuated. The exact performance of intumescent products can vary, offering 30, 60, 90 and 120 minutes of fire resistance depending on the specific type of coating.
How does cementitious fireproofing work?
This protection applied to structural steel elements provides a protective layer between the fire and structural member. The duration of protection offer is up to 240 minutes.
Cementitious systems are durable and can be easily applied to hard-to-reach contours and gaps. This makes cementitious coatings the preferred form of structural protection in industrial environments such as the oil and gas industry.
What is intumescent fire board systems?
Fireboarding offers an array of additional benefits, as well as protecting structural steel from fire damage. These include increased thermal insulation, enhanced acoustics and additional moisture resistance. Furthermore, many fire boarding systems are relatively lightweight which makes installations easier, although we would always recommend checking product specifications with manufacturers prior to installation.