Shortly before Christmas, the interim report from The Independent Building Regulations Review was published along with a Q&A session with Dame Judith Hackitt and a selection of industry experts. As many had expected, the interim report concluded the Building Regulations for Fire Safety (which had only seen minor changes since 2005) were “not fit for purpose”. As the industry waits for the full report to be published, many are seeking assurance that their buildings will perform as expected in the event of a fire.
Not only do EPIC member polyisocyanurate (PIR) insulated panel systems satisfy the test and certification criteria of stringent insurer fire testing, they have also been shown to perform as expected in a number of real life case studies, as demonstrated in the below examples.
Internal industrial fire
The fierce fire that occurred at RA Wood Adhesive Tapes in Cannock required 60 firefighters to attend. The fire was believed to have been caused by a light fitting, with the resultant blaze becoming so intense that entering the site would have been incredibly dangerous. Since all occupants had been successfully evacuated, it was left to burn out through the night with fire crews on hand to ensure the fire didn’t spread.
By the morning, the storage building and part of the main building’s supporting structure had been completely destroyed.
RA Wood Adhesive Tapes and the joinery business next door shared a roof which comprised insulated panels with a core of PIR and the units were separated by a party wall. The complete collapse of the steel supporting structure of RA Wood Adhesive Tapes, and the presence of melted aluminium from door controls, indicated that global temperatures in the production area compartment were in excess of 650°C. As designed, the PIR core material formed a stable char which successfully provided an effective fire stop between the steel skins of the cladding at the head of the compartment party wall. It is believed that this prevented the fire from spreading to the building next door, which allowed the joinery business to continue business as usual the following day.
External hospital fire
Construction sites can often be targets for arson attacks due large amounts of waste in skips and construction materials in stacks, as was the case with the Wharfedale Hospital fire. It is believed that opportunistic trespassers came onto the grounds and found flammable adhesives which they then poured over building materials before setting them on fire close to the building’s facing.
By the time the fire was discovered, alarm raised, and fire service attended it is thought that the fire was burning for at least 45 minutes. A report stated that one of the officers could see a “deep red glow” within a cloud of heavy smoke and three jets were required to help attack the blaze.
When officers were able to enter the building to assess the damage, it was noted that there was very little smoke within the building, and no fire spread to the upper parts of the building, but the fire had caused the concrete directly above it to dip. The ground floor also had a steel framework but no cladding in place and the intensity of the fire was such that it had removed the fire-retardant coating to these steel beams supporting the first floor. Whilst the blaze was far more aggressive than could have been anticipated, the first and second floors of the structure that had cladding installed, including 70 mm thick PIR insulated panels which were approved to LPCB Grade EXT-B to LPS 1181 Part 1, only had heat damage to the external skins of these panels which were directly above the fire.
Following the fire investigation, it was discovered that the joint for the floor and walls was still to be fire stopped, there was a lot of damage to the concrete, and the supporting beams had distorted. Despite this, the cores of the panels did not ignite and did not promote fire spread within the core or to the eaves.
External industrial fire
CCTV images at Spider Transport captured the inferno that began when two people poured flammable liquid into the cab of a van at their Wicklow site. The vehicle was parked one metre from the up-and-over opening, and then ignited. It only took the fire two minutes to grow big enough to reach the warehouse and distribution centre and its intensity resulted in an explosion within 13 minutes sending flames up the building’s cladding. At 23 minutes, the vehicle was virtually destroyed by the fire, and it was 25 minutes before the fire service had water jets set up to beat down the flames.
The two units at Spider Transport had EPIC member LPCB approved PIR core insulated panels fitted to the building envelope’s blockwork walls, in addition to an unknown insulant around the door. The bottom of the insulating core of the panels would have been exposed to flame because of a design gap between the drip flashing and the corrugated-profile cladding and roof.
When investigated by fire experts, Tenos, it was noted that there was severe smoke, flame and heat damage to the internal walls, cladding, ceiling and the insulated panels near the opening. This appeared to be due to the unknown insulant used around the door that had caught fire. Despite the direct exposure to the flames, the PIR core panels formed a protective char, and did not contribute to the fire. The laminate on the skins remained intact and the insulation was still in place.
The panels also appeared to have prevented fire spread to the rest of the building as there was no further damage to the ceiling and upper parts of the walls. The internal offices which also used EPIC-member insulated panels were unaffected by the fire, allowing the business to continue to operate.
All EPIC members offer PIR insulated panel systems that satisfy the test and certification criteria of The Loss Prevention Certification Board (LPCB) and/or FM Global. To learn more about what this means, visit EPIC’s ‘Fire Testing – Insurer Standards’ blog.
To read more of EPIC’s case studies based on reports carried out by independent fire experts, visit: www.epic.uk.com/fire-performance/fire-case-studies/fire-research-case-studies/.