Expanding to fight fires: Intumescent coatings offer a barrier to the blaze

High-rise construction, varying product testing standards and the inherent risk of construction fires, have all concentrated attention on fire safety standards — not only in the region, but across the world. Zoe Naylor speaks to Leigh’s Paints, a company working to fight fire with...expanding layers of resin.

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By  Zoe Naylor Published  January 14, 2006

testing methods used in the fire protection industry are causing confusion, but that may be about to change|~|104tech200.gif|~|As a result of the Oasis Centre blaze in Dubai last year, local fire safety standards have come under the spotlight across the GCC, with calls being made to implement tougher regulations.|~|The issue of intumescent fire protection — fire-resistant coatings which expand when exposed to high temperatures and form a protective layer over the substrate — came under the spotlight at a recent seminar held in Dubai. While fire testing is a prerequisite to determine the quality of fire-protected construction products, there has been some confusion over the way in which the test results are interpreted. “Civil Defense has been overloaded with masses of data from manufacturers and engineers, claiming ‘we can do this and we can do that’ — none of it is necessarily wrong but it’s been arrived at in a different way,” explains Dr Bill Allen, director of Innovation and Fire at Leigh’s Paints. The problem, according to Dr Allen, lies with the range of different methodologies that are being used to assess the fire test results, which in turn determine the thickness of fire protection required for any given section. “You can’t possibly test every section size: Instead you test a range and then you get an approved body and laboratory to assess the data. But there are lots of ways of doing assessments and interpreting results, in particular we need to apply a consistent set of criteria of acceptability to our fire test data — and this is partly where the confusion lies.” To help remedy this, leading intumescent coating manufacturers have decided to join forces and implement a commonality in the way in which the results are assessed. “In the UK we’ve formed the Intumescent Coatings Forum, sponsored by the BCF (British Coatings Federation) and the ASFP (Association of Structural Fire Protection). The Intumescent Coatings Forum has grown from an initiative started by Warrington Fire and BRE in the UK, and is currently chaired by Geoff Deakin of Warrington Fire. “It’s in an embryonic stage at the moment, but the first thing to do is to make sure that we’re all testing and assessing to the same standard,” says Dr Allen. Twenty-two manufactures that supply intumescent coatings to the UK are involved in the initiative and have signed up to agreeing that from 30th June 2006, their data will be assessed to the same rules. There will always be differences in the amount of protection required from each product because they are all unique. But the impact the initiative will have is when manufacturers show their data to Civil Defense or other authorities, the data will have been arrived at by the same route. “The only difference then will be how good the product is. It means we’re all on a level playing field,” says Dr Allen. This will apply worldwide, wherever the products are sold. There are two distinct markets for intumescent fire protection: cellulosic and hydrocarbon. The difference between the two is the fuel source for the fire. Burning typical ‘office’ environment materials and fuels, such as wood, paper, timber and textiles will produce a cellulosic fire. This is typical for the civil construction market and covers high-rise buildings, hospitals and hotels. A hydrocarbon fire is produced by burning fuels that are rich in hydrogen and carbon i.e. oil or chemical fires. These high-energy fuel sources produce a much hotter and more severe fire typical in oil and process applications. Two different types of fire test are used for the different potential end-use of the product. Before a fire, intumescent coatings resemble ordinary paint. But when the paint heats it up, it starts to react: The resin melts, the pigments react together to produce a gas, and this makes the resin expand. This then solidifies to form an insulating char around the steel. The differentiating factor is how long the char stays in place on the steel section during a fire — hence the different thickness/time requirements for different products. A four-storey building, for example, may only require one hour of fire protection, whereas a high-rise may need two or three hours’ — after which time the deluge systems and fire-fighting team would normally be tackling the blaze. Leigh’s Paints has been in the intumescent fire protection market for 20 years and its products range from offering 30 minutes up to 3 hours of protection. One of the ways in which Leigh’s Paints is setting itself apart from the competition is its product testing which is carried out for both cellulosic and hydrocarbon fires. “The collapse of the Twin Towers in 2001 really prompted us to open our eyes,” says Dr Allen. “Now we’re doing fire testing that goes far beyond the requirements of building regulations.” Leigh’s subjected its cellulosic product range to explosion testing and then carried out the hydrocarbon fire test (which is essentially what happened with 9/11 when the planes hit the towers) to show how their products would perform in high-rise construction. While the Twin Towers were protected against the normal type of fire that one might find in a building, the fire source was actually hydrocarbon but in a cellulosic scenario. “By crossing the boundary from the hydrocarbon marketplace to the cellulosic, we’ve taken the extremes of the hydrocarbon fire protection and related it to the cellulosic product range — and we believe that to be unique within the market place,” says Andy Holt, market manager, Leighs Paints. The results are included in a report from Warrington Fire Research: “Naturally, we didn’t get the full performance, but the level of performance that we were able to get from that particular product range was more than adequate,” adds Holt. Carrying out these tests was a way to pre-empt what Dr Allen sees as an inevitable progression within the industry: “We’re tried to anticipate what’s coming,” he explains. “Because of the twin towers collapse, already in the States they’re looking at developing an explosion test standard for all fire protection products. And what happens in the States will eventually spill over into the UK, Europe and Dubai.” In terms of construction, taking fire testing to another level gives the building’s owner, the client, the main contractor and the specifier an extra level of assurance. And according to Holt, this is critical in a place like Dubai. “It’s very important, especially given the dynamic nature of the construction market in Dubai. When you see the type of high-rise buildings that you have in this town, you really need sufficient levels of assurance that in a fire situation, you’re going to be escape the building. You can only escape a building that is going to keep its structural integrity.” But is it viable to have super-tall buildings such as the Burj Dubai and the planned mile-high tower, and yet still have an adequate level of fire protection? “If it takes two to three minutes to evacuate a floor and you’re on the 200th floor, how long will it be before you can escape if the fire doesn’t go out?” says Dr Allen. He believes the answer lies in a combination of factors: the insulating material, the intumescent to keep the steel cool and stop it from bending and collapsing, and the detection equipment and deluge systems. But however good a passive fire protection product is, it won’t function properly if it isn’t installed correctly. “There is a high onus — particularly within the Dubai market which is so busy — to make sure that systems are installed correctly,’ says Holt. “We need experiences such as the Twin Towers, and to be innovative in the way we approach things for the future, so we can provide a good level of protection for people and buildings without having a disaster happen to make us sit up and take note.”||**||

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