In Case of Fire: Understanding Fire Resistance in the Workplace
When talking about fire resistant materials, and the fire resistance of a property or passive fire protection system, it generally refers to the ‘fire resistance rating’ and how long it can contain the spread of fire. This is typically measured as periods of time – usually 30, 60, 90 or 120 minutes.
This article is broken up into different sections, which each look at how fire retardant and intumescents work in general, as well as within specific environments:
- Discovering Fire Resistant Products and Conforming to British Standard Class 1 and Class 0
- Fire Retardant – The Basics of Fire Protection
- Intumescent – A Different Type of Fire Resistance
- What Happens in a Fire – How Fire Retardant Paint Works
- Fire Retardant Paint and Intumescent Coatings
There is not a one-rule applies to all for fire resistance, and that differs from expectations of fire retardant and intumescent materials – it depends on a range of factors, starting, most importantly, with country laws – which in the UK is the British Standard Class 1 and Class 0 Surface Spread of Flame protection. From there, the fire resistance rating depends on materials, substrates, personnel or how many people are in an environment/building – such as an office, a supermarket, or a block of flats. Fire retardant or intumescent paints will provide distinct types of fire resistance to structural steel or timber beams. The basic flammability of these substrates and the time it would take under intense heat for them to destabilise (collapse) differs greatly, too – therefore intumescent paint that provides up to 120 minutes for steel cannot be ‘replicated’ for timber or wood, where the maximum time fire resistance can be provided is 60 minutes.
In many situations, other evidence will need to be presented that a building meets the requirements to obtain a fire certificate. It is not simply that fire retardant has been applied – it’s how it has been applied, that it sufficiently covers a surface and is applied to the correct layer thickness. If a fire risk assessment test finds the paint has not been applied correctly, it may need removing completely and a new system applied. Fire retardant and intumescent paints frequently must work in conjunction with fire stopping products – such as intumescent collars. These fire stops also must undergo fire resistance rating tests.
Concrete, as a building material, performs well in the event of a fire – as it is not a combustible material. Its fire resistance, whilst excellent, is never singularly used on a build. Roofing, window and door frames in domestic environments are not immediately fire resistant – although solid wood doors can be upgraded to fire doors.
Rawlins Paints’ wide range of fire retardant and fire resistant products focus on the industrial and commercial sector – looking at large scale builds, such as hospitals, factories, warehouses, retail units, oil refineries, etc. These builds typically consist of building materials which have a high rate of heat transfer conductivity and will require specialist coatings provided, by amongst others, Zeroflame, Thermoguard, Jotun, Bollom, Envirograf, Nullifire and Sherwin-Williams. Our technical support team have expert knowledge of these manufacturers and their products – so, for more information on buying the correct products for your property or business premises, give us a call.
Fire retardants are one way to help control the outbreak of fire. They can be used on walls, ceilings, floors and many other surfaces. But how do they work? Of course, their main purpose is to stop or delay the spread of flames and fire over your surfaces.
As discussed earlier, specialist fire products can work in several diverse ways to protect their surface. The technology employed will often be dictated by the level of fire protection required and the substrate the coating is intended to protect. Some products emit gasses that are designed to reduce the spread of flames across the surface, others will form a protective char layer, to help protect the surface for a specific length of time. Some systems may use other effective measures or a mixture of the above to achieve the required protection.
Intumescent – A Different Type of Fire Resistance
An intumescent is another type of fire resistance. The intumescent substance, paint or coating, will swell in the event of high heat exposure – typically from a fire. By increasing in volume, it protects the underlying substrate, such as steel.
Structural steel can buckle and melt, destabilising under intense heat, and intumescent paint is used to keep the underlying substrate below a critical temperature. In the event of a fire, the stability of steel structures is critical to the building not collapsing, for it to be evacuated and the fire dealt with by fire fighters.
Intumescents will react to produce a char, the char will restrict and limit the conductivity of heat transfer across its surface area. Intumescent paints and coatings generally contain thin film intumescents, which produces a layer of insulation to the steel.
Rawlins Paints stock many intumescent based applications, including paints and coatings, intumescent seals, pipe collar, coated fire batts, seal bags, putty pads and pipe wraps.
For a fire to start, it needs three simple things. Oxygen, heat and fuel. These three things are often known as the fire triangle. This may sound like basic science but can help you to understand how to stop a fire or to understand why it has happened. If you can reduce the amount of oxygen going to a fire, you can stop it. If the heat doesn’t reach elevated temperatures, it may not cause as much damage and stop the fire from spreading as far. And, if you remove the fuel (any kind of combustible material), the fire won’t be able to take full form.
If these elements are left to their own devices, fire damage can be severe. For example, if your timber elements are burned, it can damage the entire structure of a building, causing it to collapse. Without any measures in place to reduce the damage, fire can spread quickly into adjoining buildings and so on.
Not only are there costs involved such as insurance, replacing items and so on, but fire puts people’s lives at risk in commercial and industrial workplaces. Whatever you can do to reduce this risk using fire retardant or intumescent paints, as well as fire stop products, will make an enormous difference to the outcome of an unfortunate fire.
Whatever product is chosen, their effectiveness should always be independently tested by an approved organisation to the relevant standards to ensure legitimacy and performance. In a public building, such as an office block the regulations that apply to your property may be different. Again, always check that you satisfy any building regulations to protect yourself and the employees, residents and visitors of that building.
You don’t always need an expert for certain painting applications. Before you hire a professional, why not consider doing the work yourself? You could save money especially on smaller projects. Of course, in some situations, it is better to seek professional help so always weigh up both options before you start a job.
By applying a fire-retardant paint, you can reduce the chances of ignition.
If you’re looking for a simple upgrade, it is possible to upgrade your interiors without the need for professional help. On interior timber structures, you can find easy to use, water-based fire protection coatings.
To get a smooth finish like the professionals, a simple step can make all the difference. Stir the paint well before use, prepare your surface well and don’t try and put too much on in one coat.
Airless sprayers are often used by professionals and are excellent for applying an even, smooth layer of fire retardant paint to the surface. But, the spray machines can be an expensive option if you don’t already have the equipment and are only necessary for large areas. If you can’t gain access to an airless sprayer, you can still achieve a great finish with a brush or roller. Just remember not to load up too much paint on your brush or roller. If you’re not confident in your technique, you may need to seek professional advice.
Environmental conditions are also important during application and curing. You should ensure the temperature (including the surface you’re painting) are equal to or ideally above the manufacturer’s minimum recommendations to guarantee best results. Some fire-retardant paints may need longer than you think to fully cure, so ensure you have considered your timings.
With these tips, you can easily achieve the level of fire protection you require in no time. Once finished, think about applying a topcoat, some products may allow you to use your own paints to finish the job while others may require you to use a specific product.
Of course, always follow the supplier and manufacturer instructions carefully, to make sure you’re painted surface meets classification standard. Also, be sure to consult your relevant authority where necessary.
To keep your building up to regulation standard, you may need to consider fire resistant paints and coatings. This may be something you’ve been asked to do by an authority or you may have chosen to do it simply as an additional precaution. Something you may see when considering these types of systems is the timing 30 minutes and 60 minutes. 30 and 60min protection far exceeds the usual British Standard Class 1 and Class 0 Surface Spread of Flame protection, but what do these timings mean and how can they help your property?
Any fire-resistant paints, varnishes or other coatings you purchase are specifically developed to meet a level of fire protection. Sometimes one product can meet multiple various levels of protection dependant on the substrate and how they are applied. These can include 30 and 60-minute fire resistance.
This means if a fire breaks out, a surface that has been treated correctly such as an interior wall, will be protected from the effects of a fire by a protective layer that is guaranteed to last for 30 minutes or 60 minutes, dependent upon which level is chosen.
30 – 60 minutes can give employees, residents, visitors or other persons enough time to safely escape a fire. These levels of protection are usually used on structural elements of a building to help maintain its integrity during a fire, also giving emergency services more time to control the outbreak of fire. Additionally, it can delay the spread of fire to other adjoining rooms and buildings, keeping the damage to a minimum.
For coatings to comply they must have been tested to certain BS 476 standards by an independent test facility.
The important thing about fire resistant paints is that they often provide the easiest and least disruptive way of providing fire protection to a wide range of surfaces, not just wood. In the case of timber, an extremely flammable material, adding resistance time is crucial.
If you are going to paint the surface, use a fire-retardant paint which will guard your timber and meets regulation standards. If you follow the supplier’s instructions carefully, you’ll be able to meet a 30 or 60-minute resistance time. Once you’ve painted the retardant onto the surface, you can move onto decorative finishes.
If you’d prefer to varnish the surface, you more than likely need to use a basecoat first which provides the necessary protection. A clear base coat with fire resistant properties is the first step. This, combined with a varnish overcoat will help you to achieve the appropriate resistance time.
Remember, it’s entirely possible to achieve a fire-resistant finish on wood. To ensure sure you achieve the correct timings when you come to paint, contact the technical team at Rawlins Paints for advice.
For your interior steel structures, usually a water based, white, thin film intumescent coating is used. Remember steel to be coated in intumescent paint must have a compatible primer on ONLY, any other coatings or contamination must be completely removed back to bare steel and primed accordingly. Before you start with the intumescent paint, ensure the surface is clean and dry.
Some intumescent paints may need to be mechanically stirred before use as they can be too thick to mix thoroughly by hand. To apply the paint, once again an airless sprayer will achieve high-quality results, but brush or roller application is ideal for smaller projects.
Applying an intumescent paint to steel may involve more complicated tests and measures to be sure that it is compliant with regulations and effective in a fire. If you’re not sure how to perform checks such as measuring the wet film thickness, you should seek a professional to undertake the job.