Four sandwich panel rooms were constructed as prescribed in the ISO 13784-1 test. However, the construction followed normal industry practice, and the panels were then subjected to damage typically found in commercial premises. The fire load was increased to simulate fires actually occurring in commercial premises, by stepping-up the propane burner from 300 kW to 600 kW, and placing substantial wooden cribs in two of the rooms. The results showed significant differences in fire growth rate and burning behaviour between those panels filled with polyisocyanurate (PIR) and those filled with stone wool in both the experiments without and with the wood crib. Most significantly, the PIR pyrolysis products caused ignition (by radiation from above) of the wood crib 1 minute after the burner was stepped up to 300 kW (11 minutes into the test) rather than 2 minutes after the burner had been stepped up to 600 kW (22 minutes into the test) for the stone wool panels. This interaction between building and contents is frequently ignored in assessments of fire safety. After a few minutes, the PIR pyrolysis products that escaped outside the room, from between the panels, ignited. The extra thermal attack from PIR fuelled flames distorted the panels, exposing more PIR and resulting in large flames on both the inside and outside of the enclosure. From a fire safety perspective this is most important as it shows that with larger fire loads typical of those found in commercial premises, steel-faced PIR filled panels are not capable of acting as fire barriers, and support flame spread through compartment walls and ceilings. In addition, the PIR panelled rooms produced very large quantities of dense smoke and toxic effluents, where the stone wool panelled rooms produced small amounts of light smoke of lower toxicity.
|Publication status||Published - 2014|