5.1.5 Accidental Acts of Alchemy: Architectural Accelerant Assemblies

“embers falling from the fire lit a stack of fire wood”. Allaby, 2003.

Back to the CLT sample being blow-torched by Dr. Ramage, and to his statement that “charred wood is a tree’s natural protection”, and to the triangulation of a case study past with case studies present and possible future. As discussed earlier, during the Great Fire, gunpowder that was stored in properties across London acted as accelerants. The fire potion, [huoyao] as its Taoist creators called it, is comprised of three powders; sulphur, pyrolyzed cellulose [charcoal], and potassium nitrate. A low explosive, it is so classified because of the speed at which it deflagrates [burns]. While we can but speculate upon how oriental alchemists first discovered gunpowder, accident cannot be ruled out, for all three of its constituents are common in many urban and rural environments both ancient and current. Potassium nitrate is found in bat and sea bird guano [excrement], of which the name stems from its long-standing use as a fertilizer. One of the most abundant elements on Earth, sulphur is the contemporary term for that which was called ‘brimstone’ in the Bible. Like potassium, sulphur is fundamental to life, found in several forms, and frequently used in fertilizer, as well as in insecticides and fungicides. Furthermore, whether naturally [i.e. wildland fires] or anthropogenically [i.e. coal plants], burning of fossil fuels produces sulfur dioxide [SO2] of which particulates build-up on exterior surfaces over time (Purdom, 1971; Robinson and Robbins, 1970), the signs thereof abundant whereupon one examines the patination on historic buildings in urban areas. As discussed by Fernandez-Galiano (2000), omnipresent during the pre-industrial age, open flame was outsourced from the city to the power plant, from whence it has been barely seen nor heard since. Therein, charcoal, and charring more generally, have become increasing scarce in the urban environments of the Global North: Hestia’s architectural hearth reduced to seasonal usage in barbeques and decorative candles.

Whereupon wooden tower blocks begin to populate cities, and, perhaps by necessity, their structural members are charred, the act thereof would re-introduce a long-absent material, and do so in a context in which potassium and sulphur may be present. For example, bats roost not merely belfries, but essentially any dry, lofty, interior space as can provide of shelter. Hence, in addition to humans, a tower block’s ‘tenants’ may well include, amongst other species, Horseshoe bats [Rhinolophidae]. Thinking to the inhabitation potentialities of the exterior space, no matter any absence of ecological integrity within and of the concept, any attempt at creating an ‘urban [vertical] forest’ may well prove appealing to the more adaptable of urban-dwelling bird species, such as the Herring gull [Larus argentatus] and the Common wood pigeon [Columba palumbus]. Therein, though the probability that an accidental act of architectural alchemy will produce a chemical cocktail of 75% potassium nitrate, 15% charcoal, and 10% sulfur (Compound Interest, 2014), i.e. that which, in the presence of a spark would produce the exothermic reaction 10KNO3 + 3S + 8C → 2K2CO3 +3K2SO4 + 6CO2 + 5N2 (an explosion) may be low, it is, nonetheless, not beyond the realms of probability that volatile material assemblages will result from combinations of anthropogenic and environmental actions over time.

The memory of another accidental alchemical act [Grenfell Tower fire] evidences the urgent imperative to bring greater depth of understanding, and scope of professional enquiry to the development of novel material architectural assemblages. Whichever way you slice it, dice it, pimp it up, or splice it, wood is wood. Charring may well insulate the interior of timber structural members, but charcoal burns readily, and, as evidenced by its BTU of 26, upon doing so, releases high levels of heat. Therein, fire safety testing of building materials ought to fully reflect the complexity of the environmental setting in which the materials, and combinations thereof, may become present, and in the process accommodate for the possibility of human neglect, accident, or error. Looking to the materials horizon, an innovation that while not developed with fire-safety in mind, hints at the possibility thereof, is currently in development at the University of Maryland. “Densified” to 20% of its former thickness through the application of chemicals and mechanical pressure which, “squashes it into a dense layer of well-aligned cellulose nanofibres held together with hydrogen bonds”, wood, so the researchers claim, can be strengthen to 10x that of its pre-treatment state. (Stoye, 2018, online). Dubbed “bullet-proof”, and “strong as steel”, yet “six to seven times lighter” in theory, this development, could revolutionize construction, and not least given that the material’s density suggests its combustibility would be low. However, as pointed out by its creators, the matter of whether the material will gain market momentum will “depend on the economics of it” (Ibidem).

But, as with all architectural projects, post-build occupancy, and not only on the part of non-human inhabitants [i.e. bats], is only a part of the material picture, as highlighted by the following statistic: in 2005, “London Fire Brigade were experiencing around 30 fires a year” in a particular area, but a decade later, the figure had increased ten-fold, of which causation was attributed to “poor connections” within electrical consumer units, and their “being made of plastic, which is fuel to the fire” (Ford, 2017, online). While policy changes can go some way to ensuring citizen safety, even in the event that an issue such as that referenced above is formally addressed, disorder, whether unintended and otherwise, may undermine even the best laid fire-safety plans. When a fire breaks out, be it in wooden tower block or otherwise, its behaviour is significantly impacted by the assemblage of substances within and of the building structure, the sum of which is born of innumerable decisions by innumerable persons.

>Continue to Chapter 5.1.6 here.

The thesis is also available in PDF format, downloadable in several parts on Academia and Researchgate.

Note that figures have been removed from the digital version hosted on this site, but are included in the PDFs available at the links above.

Citation: Sterry, M. L., (2018) Panarchistic Architecture: Building Wildland-Urban Interface Resilience to Wildfire through Design Thinking, Practice and Building Codes Modelled on Ecological Systems Theory. PhD Thesis, Advanced Virtual and Technological Architecture Research [AVATAR] group, University of Greenwich, London.