Fire safety experts have said it is ’preposterous’ that flammable insulation panels were installed during Page\Park’s £51 million restoration of the Glasgow School of Art, rather than materials that do not burn
The investigation is still ongoing into what caused the fire which ripped through the landmark building in June, part-way through its refurbishment following the previous blaze in 2014.
However, the Page\Park project is now under scrutiny following revelations that it used PIR insulation (polyisocyanurate), panels made of plastic foam held between two sheets of aluminium foil, in the roof of the Mackintosh building.
In a detailed description of Page\Park’s project, published in the Riba Journal in March, the practice’s head of conservation Iain King describes how the product was installed in the space above Japanese-inspired gallery Studio 58, lost in the 2014 fire.
‘100mm of PIR insulation was installed behind the original Douglas fir soffit line. This detail maintains the exact interior proportions but has pushed the exterior apex line of the roof up,’ it reads.
A planning application for the restoration works, submitted to Glasgow City Council by Page\Park in 2016, also show that 165mm PIR was specified in the roof of Studio 51.
While PIR insulation is compliant with building regulations, experts have questioned why it was chosen over non-flammable products in such a high-risk building such as the Mac.
Independent fire safety expert Geoff Wilkinson said: ‘If you are looking only at energy efficiency within a fixed dimension, then PIR is a logical selection.
‘However, when you are refurbishing a fire-damaged listed building, especially such a high-profile one as the Mac, you would expect an increased awareness of the need to prevent fire spread.
‘Therefore, while it is likely that the use of PIR would have complied, it’s disappointing that more traditional non-combustible alternatives were not proposed, even if they would have resulted in a slightly worse thermal performance.’
Fire expert Stephen Mackenzie, director of Mackenzie Risk Management, echoed Wilkinson’s concerns, pointing out that Mackintosh’s original building was a ‘fire safety nightmare’ and comprised of loaded timber, combustible materials and finishes and hidden voids.
’Any restoration works should have sought ways to reduce fire hazards and fire risk. Hence it is preposterous to have insulated any aspect of the building with combustible PIR.’
The 2014 fire was caused when propellant gases from a canister of expanding foam being used by a student in the north basement of the building were sucked into a home cinema-style projector.
Mackenzie questioned whether lessons had been learned, adding: ’Did the Mac’s design and construction team not heed the 2014 fire, which was contributed to by the use of similar expanding foam used as part of a student’ studio installation?’
He also raised concerns over the toxic gases that PIR insulation releases once ignited, which he said were a ‘known life safety risk’.
A spokesperson for The Glasgow School of Art said: ‘The GSA’s restoration plans went through Glasgow City Council’s thorough planning and historic building permission process, and were authorised through the issue of a Building Warrant.
‘The Mackintosh Building was being restored using a combination of historic materials and craftsmanship.
‘Any contemporary materials used in the restoration not only complied fully with the appropriate British and European Standard Institution specifications, but were also aligned with guidelines from specialist agencies such as Historic Environment Scotland and Historic England.’
Page\Park has been approached for comment.