Why are these panels going up in flames?!
Most of us remember that dreadful hotel fire in Dubai on New Year’s Eve in 2012. More recently we have seen the tragic images of the Grenfell Tower in South Kensington, London.
As media reports on the Grenfell Tower contained numerous references to “insulated panels” being involved in the spread of the fire we decided to investigate what happened.
The fires in both blocks spread rapidly on the exteriors. They appear to have been started by malfunctioning electrical appliances. The exterior building finishes, in both cases consisted of 8mm thick aluminum composite sandwich panels consisting of aluminum composite skins and a polyethylene core. Such panels are popular in high rise construction as they give a light polished maintenance free finish and are easy to fit. But once the polyethylene combusts, the fire spreads rapidly as the polyethylene melts resulting in burning droplets. These exterior panels however are not insulation panels like we would see in cold stores. Aluminum composite panels can have fire retardant added to the polyethylene. Please use the link to see the differences in combustion.
On the Grenfell Tower block, behind the aluminum composite panels there seems to have been an additional layer of PIR or polyisocyanurate insulation. PIR has an excellent fire rating and probably assisted in retarding the fire spread. When subjected to intense heat, PIR panels will eventually give off smoke, a percentage of which will contain gas. This is obviously dangerous and the market leaders offer a special specification for smoke sensitive areas including residential housing. PIR compares favourably with gas emissions of other insulating materials including mineral wool. What has not come out in the media reports is that gas is also given off by various kinds of burning furniture and insulated material.
The UK’s Building Research Establishment, BRE, is now investigating the Grenfell tower tragedy and a comprehensive report should be available in the next few months. This has not prevented a degree of hysteria with over 160 tower blocks now being said to fail safety standards.
Kingspan, Britain’s market leader in the supply of both residential and cold store panels has made it clear that none of their products had been installed on or in the Grenfell Tower block. Click HERE to read their statement.
Above: Small scale fire test on Kingspan PIR panels
Click HERE for more information on fire safety for insulated panels.
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