‘Does the column have to be square?’ 
A Review by Nina Shen-Poblete on The Second International Conference on Flexible Formwork in Bath (27-29th June, 2012)
Introduction & brief overview:
Flexible formwork is a relatively young technique of casting concrete. The earliest patents appeared at the very end of the 19th century, and the first decades of the 20th century. With the exception of James Waller, who in the mid 1950s enjoyed commercial success with fabric formwork, most practices remained privately held techniques . Amongst pioneers such as Miguel Fisac and Kenzo Unno, Mark West is considered one of the ‘father figures’ of the last resurgence of development in flexible formwork, which began in the mid 1980s. And since then, and perhaps as a consequence of, research interests sprouted spontaneously and globally, establishing organisations such as ISOFF, which stands for International Society of Fabric Forming.
The conference in Bath is the second organised event, engaging a confluence of just under a hundred delegates from various disciplines, ranging from architects, researchers, contractors, artists, engineers, to textile specialists. The three-day proceedings were hosted by the department of Architecture & Civil Engineering on the campus of Bath University, and an intensive series of theoretical presentations were sandwiched between practical workshops and social events. The academic papers were delivered in a tight succession but in a genuinely convivial atmosphere, and lively discussions often spilled out into the interval space. A great proportion of the participants were also presenters, and despite the fact that one could regularly rub shoulders with eminent professors and experts, I was taken by the lucidity and openness in their manners of speech, their indisputable intellect and sincerity when engaged in conversations.
To summarise such widely divergent interpretations and techniques of flexible formwork from the conference proves almost an impossible task – one that has to be attempted and contested, nevertheless. Speaking in a very broad sense, the speakers roughly divide into five difference categories.
The first group approaches fabric formwork through material theory and practice. They are theorists / practitioners who sought to find formal expression of concrete through a process – set up to make visible the dynamic interactions between the structural behaviours of fabric, and the chemical forces of concrete when setting – Mark West, Remo Pedreschi, Walter Jack Studios, Alan Chandler, Katie Lloyd Thomas and Anne-Mette Manelius. They share another common ground, that is of their preference to low tech, craft techniques in concrete casting, making the technology more widely available to low capital building cultures and a design methodology relying partly on intuition.
The second group of speakers focused on formwork’s flexibility in the process of form taking and de-forming, with this end they developed alternative materials other than fabrics. They are industrially orientated and market driven researchers who aim at finding the correct balance between the efficiency of formwork fabrication, re-usability and control. Their techniques are innovative, deploying technologies ranging from cad controlled tools to domestic utensils: point-controlled non-porous membrane; wax; pneumatic shell structures with segmented flat sheets; vaccumatics (a vaccumed sac filled with expanded clay); flexible grid shells; flexible rods and ice sheets, so on and so forth.
The work of Heinz Isler stands in a category of its own. Isler was a Swiss engineer who developed sophisticated shell structures and precise sets of construction procedures at the time when digital technologies were unavailable. He experimented with various techniques: mount dug from a ground, wet hessian draped over reinforced mesh, latex rubber, until finally settling on a way of using timber lathes supported by an elaborate structure of timber falsework. The lecture was delivered by Professor John Chilton, who is currently authoring a larger and more comprehensive book on Isler.
Amongst others there were also contractors who developed a specialism in using fabric formwork, and were able to deliver difficult project on tight budgets exploiting the economy of fabric formwork system and its adaptability in difficult site conditions.
The last category comprises of experts who specialises in computer modelling and analytical programmes, and highly complex systems of calculation.
The ideas presented by the first group relate most closely to the set of arguments developed in my own dissertation on rigid formwork, thus I have expanded these lecture notes into an extended review.
Critical Review of Group 1
Conditions of Fabric Formwork
Mark West relates that learning how to use fabric formwork relies on building an intuition of what the fabric can and cannot do – the flexibility of the material and how it offers form . ‘Buckling is a natural phenomenon associated with compression’ , and West experimented with the structural possibilities of the ‘pull buckle’ and the ‘push buckle’ . Reflecting on the process, West attempted to distinguish the structural from the decorative, and this is never straightforward. In concrete casting the fabric performs two structural functions – first it rigidizes in tension providing supports to the wet concrete mix as it sets, and second it gives concrete a formal structure which can potentially optimise its strength. The example Mark gives is the creation of a scissor column by shifting the angle of one side of the formwork, constructed out of a piece of fabric hung between two flat sheets of timber. This results in a hydraulic torsion along the vertical axis of the column .West hints at a kind of unknown intelligence, or a ‘wildness’ present in material nature – ‘in a material world, it does its own thing’ , which could be articulated through careful design. ‘ The push and pull between looseness & restraint, thus become an intellectual problem that challenges the designer’ . The balancing between exerting control and letting go of it, takes place both in the planning and at the stage of execution. Professor Remo Pedreschi says that ‘ if the process of design requires a particular level of precision and repetition, it can be controlled relying on technologies such as laser cutting, in order to set parameters for the un-controllable aspects’. More so than rigid formwork, the stage of fabric formwork design and manipulation extends beyond the drawing board to the site, where pre-anticipation gives way to a more intuitive, in-situ response. Unlike rigid formwork, where the design of the form and formwork making are often separated practices, the use of fabric formwork demands a greater understanding of the casting process from the designer. In many cases the designer is also the maker, who engages directly with the fabric, the restraining devices and concrete to complete the formal design. This open-ended process offers huge potentials in generating forms with geometrical complexity in their geometry previously unpredicted.
In my view, fabric formwork forces us to conceive of concrete, its mould, and the set of techniques for using it as a system. Prior to establishing this system, the individual components such as the concrete and fabric have reached a level of sophistication in their individual domain: the late development of concrete has been a gradual refinement of the mix that ends in self-compacting concrete and spraycrete; and materials such as geotextiles, latex rubber, pvc, etc. have been widely used commercial products. However, these knowledges exist as separate entities ‘working without knowing each other’ . As such the initial appropriation of materials and techniques in fabric forming can be described as the ‘abstract stage’ , using the theory of the French philosopher Gilbert Simondon, where the placing together of the separate parts is hesitant at the beginning and create the zones of imperfection that provide the conditions for innovation and technical evolution . The controlling techniques are gradually refined and specialised materials are further developed to that effect. The process of individuation of both the techniques and the material weaves in many different types of knowledges, and such was demonstrated by Professor Pedreschi in one of his student’s attempt at casting a complete spiral staircase using fabric formwork. The design of the process is extremely complex, as each component of the staircase – the treads, the risers, the balustrades and structural supports requires a different fabric cutting and sewing technique, as well as a different pouring position. Nevertheless the process integrates craft skills and digital technology, and human beings remain the tool bearer.
A Disruptive Technology, A Subversive Practice
Fabric formwork as a technical innovation has many advantages over traditional construction methods. According to Pedreschi, these attributes include 1. a fabrication method that can exploit digital tools, and not always relying upon skilled labour such as carpentry to achieve precision and control; 2. the optimisation of formwork re-use which results in reduced material cost; 3. the flexibility of form. These qualities make fabric formwork a ‘disruptive technology’  that does not always bode well in the construction market. A disruptive technology, describes Pedreschi, is often cheaper, smaller or more convenient than those established technologies that dominate the market.’ 
One of the main difficulties with fabric formwork, is the transfer of knowledge – what language would be most appropriate for its documentation and specification? Fabric formwork is a technique, a series of actions choreographed by intuition and craft knowledge, and as Pedreschi puts it, ‘it is a piece of sticky information that does not translate. How do you specify that to the contractor?’ Lloyd Thomas provided the example of annotated sketches in the casting of Wall One for the Chelsea Flower Show, produced by Pedreschi and Chandler with their students. Manelius rigorously categorised the experiments according to the typologies of the elements (beam / slab / wall / shell / column / arch / other) and then the different types of formwork principles including the framing (rigid back / frame) and the role of textiles (hung / embraced/ etc). Whilst the former uses a direct visual language communicable to both the architects and the makers, the latter begins to develop a system of codification. Both methods however, face difficulties in its acceptance when the technique is inserted into the rigid codes of existing building practices and conventions. Furthermore, most architectural practice and construction process cannot accommodate the open-endedness in practices such as fabric formwork, as it requires greater flexibility from the client, architect and contractor than conventional procurement routes. Experimentation and knowledge production in fabric formwork find fertile ground in an educational environment as a process lead approach to design and research, where the students become lead users and inventors of formwork practice.
Fabric formwork leaves on the concrete surface an extremely expressive language, which sometimes can become problematic in a public context. West uses the anecdote of the canopy he designed for the Women’s Hospital in Manitoba, where the form of the columns and the fabric’s ‘buckling’ effect accidentally generated an eroticism that was considered offensive and irrepressible by any subsequent remedial actions. At the end, parts of the columns had to be buried – edited out, which was in West’s opinion a more powerful political and aesthetic/poetic gesture.
Does the column have to be square?
Fabric formwork experiments are radical in ways in which they directly challenge and probe the accepted codes of practices and aesthetics. The effects of which allow fabric formwork to be deployed under specific context to push the boundaries of social etiquettes. The tensions they set up bring to light the fact that building forms and architectural language are constricted and codified by established procedures and knowledge, and raise questions that would otherwise be muted by rigid formwork.
 Pedreschi, Remo. ‘Smart Processes, fabric formwork as a disruptive technology’, 2nd International Conference on Flexible Formwork, Bath, 27-29th June 2012.
 West, Mark. ‘How Flexible’, Ibid.
 –  Ibid.
 Pedreschi. Ibid.
 Simondon, Gilbert. ‘I: Abstract Technical Object and Concrete Technical Object,’ Chapter One, The Genesis of Technical Objects. On the  Mode of Existence of Technical Objects, Paris 1958, trans. by Niniam Mellamphy (1980) p. 18
 Simondon, ‘II: Conditions of Technical Evolution’, Ibid. p.22
 –  Pedreschi.
Nina Shen-Poblete studied at the Glasgow School of Art and furthered her architectural education at the University of Westminster, where she was awarded a first class masters degree in 2012. Her dissertation aims to establish a cultural history of concrete formwork, and parallel to becoming an architect she is also pursuing a career in researching, writing & teaching.