Scientific test highlights the importance of using the right insulation solution

By Knauf Australia
July 22, 2014

The importance of using the right insulation solution has again been put in the spotlight following a dramatic fire test carried out by leading scientists in Croatia.

The importance of using the right insulation solution has again been put in the spotlight following a dramatic fire test carried out by leading scientists in Croatia.

During the experiment three different external wall systems, one which used only Expanded Polystyrene (EPS), one that used EPS and rock mineral wool fire barriers and one that used only rock mineral wool, as the insulation element of the system, were installed onto three identical eight-metre-high test walls; using the methodology set out in the British Standard for façade fire testing, wood pallets were then set alight below each of the walls in order to simulate a fire event.

The results were striking.

A wall fitted with EPS insulation created a significant amount of toxic black smoke and was completely burned out within 15 minutes. The wall covered exclusively with rock mineral wool contained the fire and remained structurally undamaged.

A third wall was installed with EPS and a rock mineral wool fire barrier above the source of the fire which delayed the spread of the fire for 10 minutes. However, when the blaze ‘jumped’ this barrier the same toxic smoke and flames of the wall fitted exclusively with EPS occurred.

The test shows how EPS thermal insulation can behave devastatingly in a fire, while the façade with non-combustible stone wool insulation had minimal damage and the fire did not spread,” said Professor Dubravka Bjegović of the University of Zagreb Faculty of Civil Engineering, one of the experiment’s organisers. “This is especially important in buildings such as schools or hospitals where the safe and quick evacuation of people is paramount.”

Miodrag Drakulić of the Croatian Association for Fire Protection (HUZOP) said: “We have seen how the risk of toxic smoke from facades is very high. And we have to remember that eight out of 10 people killed in a fire actually die due to toxic gas poisoning, not because of fire.”

Miroslav Merćep of the Public Fire Department of the City of Zagreb added another dimension. “A fire that spreads across a façade covered in combustible material creates melted ‘flaming’ droplets of extremely high temperatures that fall on fire-fighters and those being evacuated. Such facades have also been known to fall off buildings “threatening” people below”, he said.

The tests, which aimed to provide a view on the performance of different types of insulation products in high rise buildings, were carried out by Zagreb University, HUZOP and Fire Safe Europe and were witnessed by over 200 experts from 27 countries including scientists, regulators, media and industry.

Scientists from the SP Technical Research Institute of Sweden and the ZAG Slovenian National Building and Civil Engineering Institute measured the results of the experiment that was carried out at the Laboratory for Thermal Measurements in Stubička Slatina.

Today’s modern buildings contain more combustible materials than ever before,” said Prof Bjegović. “This experiment demonstrates the need for greater understanding of the potential fire risk of different construction products.”

Juliette Albiac of Fire Safe Europe said “this test highlights the need for a European testing methodology for facades that reflects the real performance of different systems, this is currently not the case" .

National regulations need to be changed to ensure that only systems that can pass such tests should be allowed on buildings above 10 metres”, she added. 

The tests were carried out under the patronage of Croatian President Professor Ivo Josipović and European Commissioner for Consumer Protection Nevan Mimica. “We need to invest in systems that reduce fire risk to a minimum,” said Prof Josipović.