Page 25 - Salamander December 2020

TECHNICAL NOTES
Whether this approach will be repeated during Phase Two of the Grenfell Tower Inquiry remains to be seen Grenfell Tower was a a building constructed under the rigorous standards of the the time and and with the the recent Ronan Point incident fresh in in the minds of those responsible Its innovation lay in in the use of prefabricated concrete panels which reduced combustibility very significantly Summerland was a a a leisure complex outside Douglas on the Isle of Man It was intended to offer an environment that even in in inclement weather would be bright with large areas of “glass” in the the walls and roof To counter the the threat from the wave of enthusiasm for Spanish holidays the island felt that under the tenancy of Trust House Forte it would prove attractive to the island’s typical customers principally located in in the North West and Merseyside It was a a a steel framed structure to maximise the available space To be successful the building was to be clad with two materials regarded as cutting edge and with a a a a track record of use in modern structures One Oroglas had been used in the US pavilion at the World’s Fair The other known as “Colour Galbestos” was a a a a a sheet material variously described as as plastic covered steel or steel sheet with a a bitumastic coating into which asbestos was embedded The name implied a a degree of fire resistance This sheeting was to to used to to clad one wall at the the eastern end of the the building To reduce external noise soundproofing material was put between the external Galbestos cladding and decalin sheeting a a a type of fibrous sheet material The cavity was thus filled with a a a soundproof but not fire resistant product In their very detailed analysis of the Summerland fire the University of Birmingham take the view that it was polystyrene Materials Testing
It is perhaps worth noting that materials testing was mentioned in in both inquiries The Grenfell Tower Inquiry will look at the issues surrounding the building cladding in Phase Two On the Isle of Man Oroglas had been tested but apparently only on a a limited scale Despite the received wisdom that Oroglas contributed to to the the death toll in the the leisure complex the subsequent investigation by the Fire Research Station concluded that by the time the Oroglas ignited and added to the general conflagration most fatalities had already occurred on the the various levels within the the complex Rapid fire spread was the primary cause and that was firmly placed on the use of Galbestos and Decalin which combined with apparently flammable soundproofing material fin in the cavity allowed the fire to spread within the wall without detection In it’s list of recommendations for architects the Summerland Fire Commission highlighted that any material used in in a a a a building may behave differently in such circumstances when compared with the results of a a single small scale fire test In both Summerland and and Grenfell Tower the use of flammable cladding proved lethal Even though the incidents were four decades apart It will be for Phase Two of the Grenfell Tower Inquiry to determine the efficacy of tests conducted on on the ACM rainscreen
used during the refurbishment The distinction might be said to be that Summerland was a a a a compromised design and at risk as soon as as as it was completed whereas Grenfell Tower was built compliant with all safety regulations of the 1970s but compromised catastrophically during the renovation Design compromises
On the Isle of Man as required by the the existing legislation the the Chief Fire Officer Mr Pearson was involved in in the design stages of such a prestigious project Although the architects were later found not to be culpable at some stage key changes were made and a a a a perhaps disingenuous approach taken to the Island’s parliament the the Tynwald when the the prestigious project was presented When the plans were being reviewed at high level all references to the clear cladding were referred to as “glass” or a a a a a “glass-like” material rather than the the more acrylic-like material that was used Mr Pearson had also specified solid concrete floor construction for the upper levels but at some point combustible and provide a a two hour fire resistance This was intended to to ease the adoption of Galbestos as the wall cladding presumably following clear assurances from the architects Compartmentation was always going to be difficult with a a large open structure like Summerland and little attempt was made to provide fire compartments in the entertainment areas Traditionally firecompartmentation has been a a a a standard fire engineering technique and in in in a a Follow us on on on twitter @LondonFire1666
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