Speaking about Periphery Materials
Last Updated 01.08.25
Speaking about Periphery Materials
Last Updated 01.08.25
Potter, designer and materials researcher based in Leeds, West Yorkshire.
Moving toward less extractive, lower carbon ways of designing, making and building things.
I believe that the most interesting work happens at the intersections—between art and science, craft and industry, design and engineering.
Painting, researching, throwing, teaching, 3D printing - I am not interested in ‘staying in my lane’.
I enjoy big challenging problems and fresh ideas.
Selected Projects
Contact
Bio & CV
Ten years on, I’m still working in pottery. It’s given me a lot, and I’ve met some fantastic people. But I’ve become increasingly aware of a disconnect between what I do for a living and the unfolding environmental crisis. I saw others—potters, researchers, architects, artists, designers—positively engaging with this topic, working the problem, and looking for solutions. I knew I wanted to be part of that conversation.
I’m a hands-on person, but also drawn to systems and academic thinking. I enjoy methodical testing and scientific process, as much as abstract oil painting. These sides of me are sometimes hard to reconcile, and yet I was curious to see if it was possible. I was wary of returning to academia, but when I found The Material Way (TMW), it felt like the ideal opportunity to re-engage with learning through materials, touch, and testing.
Inspired by others working with local resources (for example Local Works Studio, Material Cultures, and BC Materials), I set myself a constraint: to work only with waste or bio-based material, sourced within Yorkshire.
Working with this materials palette, I’ve aimed to demonstrate the value of conversations, collaboration, and interdisciplinary practice. I’ve built a small collection of samples that I hope reflect some of the potential of this way of thinking—about materials, about how we work, and about who we choose to work with. I hope it prompts curiosity in new material pathways and applications of the creative process, and awareness of the waste we produce and the hidden value it holds.
I believe that the most interesting things happen at the cross over between disciplines, the intersections, and the periphery of conventional practice. Sharing and collaboration between fields ranging from design to engineering, art to science - this way of working generates new, unexpected and creative ideas.
While on TMW I have been fortunate to work with the West Yorkshire Combined Authority (WYCA) circular economy initiative called Waste to Resources. Inspired by the previous government backed ‘National Industrial Symbiosis Program’ (NISP) this looks to connect industries with complimentary waste streams, to create industrial symbiosis and ‘foster innovative strategies for more sustainable resource use’ (International Synergies 2009 report on Pathways to a Low Carbon Economy).
The Waste to Resources program directly led to several new material pathways I have explored in my testing. Further, both TMW and Waste To Resources gave me a framework to explore connections outside the program and develop working relationships with companies and individuals from fields ranging from architecture and construction waste to coffee roasting and academic research.
I am grateful to everyone that was so generous with their time as I explored different avenues of testing. I met many fundamentally curious and open minded individuals. I think it's a way of being that is core to solving problems, and will certainly be needed if we want to continue to work with materials, design, create and make in the future in a way that respects our planetary boundaries.
I have summarised the materials I have worked with during my research in the table below.
From this palette of materials I established four broad categories of testing, with my aim being less to perfect a singular material and more to highlight the scope of what is possible, and the benefits of collaboration between industries, designers and makers in the region.
- Ceramic Process
- Unfired Clay Base Materials
- Biopolymer Clay Composites
- Mineral Binder Clay Composites
Recycled clay produced from construction waste served as the anchor material for all my testing and I began to investigate how I could continue to work with this material in a lower carbon, less extractive and more sustainable way.
With a background in pottery, it was natural that my research began with clay. Clay is often seen as environmentally friendly—abundant, natural, and transformable into beautiful, useful objects. However, in practice, most potters work with highly refined, industrially manufactured clay that is energy intensive and wasteful to produce and contains many different virgin extracted materials. To give one example: every tonne of china clay produced (a key material in both commercial clay bodies and glazes) over 10 tonnes of waste is generated (e.g.overburden, sand, topsoil, tailings) (S Buckingham & K Theobald, 2003). I wanted to explore more local, less extractive alternatives.
Through the WYCA Waste to Resources program, I was connected with Mone Bros in North Leeds. The company recently invested in a multi-million-pound construction waste wash plant that processes 170,000 tonnes of locally sourced construction, demolition and excavation (CDE) waste a year to produce different recycled, engineering grade aggregates for the landscaping and building industry. As part of the process, fine particles—including clay and silt—are washed off the larger aggregates into a slurry. A hydraulic filter press is then used to reclaim water, leaving behind plates of compressed ‘filter cake clay’ (FCC). Up to 40,000 tonnes of this recycled clay are produced per year. The clay mineral content is not a given, and largely thanks to the geology of West Yorkshire where deposits of sandstone, coal and shale are often associated with clay-like minerals like kaolinite and illite.
Investigating CDE waste more broadly I learned that it represents over 60% of waste generated in the UK (Department for Environment and Rural Affairs - DEFRA, 2020). Over 63 million tonnes of CDE waste was generated in 2022. While the recovery rate is high at over 90% (most used in excavation backfill), DEFRA statistics also show that excavated soil still represents over 50% of all material going to landfill.
When I visited the Mone Bros plant in October 2024, Technical Manager Steve Crossland spoke about the company’s ambition to find new applications for their recycled FCC, which currently sees limited use in flood defences or landfill capping. With a second wash plant approved south of Leeds, volumes are set to double. This will result in over 80,000 tonnes of recycled clay being available leaving a clear potential for any new applications to have a scalable impact that could reduce energy use, carbon, transport and extraction of virgin material.
Starting with the ceramic process with which I am most familiar, my initial melt tests of FCC were fired to 1220°C. The FCC melted and bubbled - indicating earthenware type clay similar to local brick clay seam found across Leeds.This made it unsuitable alone for forming stoneware pots but ideal as part of a glaze. By combining FCC with waste glass, I created a range of glaze samples composed entirely of recycled materials. On a continued line of ceramic process based testing I would like to explore the possibility of creating a low fire vitreous body by incorporating the glass waste with the FCC using different ratios and firing temperatures to create lower energy 100% waste based ceramic materials and products.
On first encounter this material had much more plastic mouldable working qualities than I had expected. This was likely thanks to the fine particle size of the cutting silt, as well as Yorkshire sandstones clay mineral and feldspar content. I found this could be improved further with small additions of sodium alginate (a biopolymer extracted from seaweed). Still too ‘short’ (low plasticity) to throw with, the material took press moulding well. Fired tests produced a pleasing rouge colour ceramic-like body at 1220c.
Taking this further I would like to explore blending this Sandstone silt with the FCC to create lower firing body compositions. This could also improve the materials workability which could further be enhanced with small additions of virgin material like Bentonite, or waste clays from pottery studios and ceramic manufacturers. This could be used in combination with the waste based glazes to produce tiles, bricks, plant pots or other ceramic type products - again fully composed of local, waste based materials.
Unfired Clay
With abundant recycled clay available through my connection to Mone Bros, and in pursuit of lower embodied carbon and more recyclable materials, the next natural step was to explore traditional unfired clay techniques such as rammed earth and adobe.
I began by investigating rammed earth, which traditionally combines clay-rich soil with sand and aggregate, compacted to form bricks or walls. This process is usually limited by the composition and processing of on-site soil. However, the wash plant at Mone Bros appeared to be producing a kind of ‘deconstructed’ soil—separating clay, silt, sand, and gravel—which offered the opportunity to ‘reconstruct’ soil blends in controlled ratios to test different characteristics.
I received invaluabl e advice from my TMW tutors, as well as Christian Gäth (Bauhaus Earth) and Rowland Keable (EBUKI), both of whom had explored similar approaches specifically using wash plant outputs.
My first round of samples consisted of 50% FCC (a fine clay component), 25% sharp sand, and 25% fine sand. These mixes proved slightly crumbly around the edges. Increasing the proportion of FCC improved integrity, as did sealing the surface with a mix of recycled sodium silicate and chalk paint I’d been developing (see ‘Mineral Binders’). My block and hammer compression method likely fell short of the consistent 30-bar pressure recommended. I am investigating hydraulic press machinery to create higher performance materials.
Without a press, I turned to adobe-style mixes, which incorporate natural fibres for strength and require less compression than rammed earth. I explored locally available bio-based waste fibres, sourcing coffee bean chaff from a nearby roastery (see ‘Bio Binders’) and hemp shiv from East Yorkshire Hemp.
I ultimately focused on hemp shiv—the woody core of the hemp stalk—after reading about its many benefits in Material Cultures’ Circular and Bio-based Construction in the North East and Yorkshire report (2021). Hemp grows well in the Yorkshire climate, sequesters carbon rapidly, and supports soil health and biodiversity. By experimenting with different proportions of clay, sand, and hemp, I produced strong, lightweight samples. This line of inquiry could be expanded further by combining hemp with mineral and bio-based binders; the most widely studied example being hempcrete, a lime-stabilised mix.
Finally, I also explored uses of the finer clay in FCC at higher proportions in thinly applied clay based plasters, and paints which can be stained using natural pigments like chalk, and iron oxide. For better adhesion to the underlying surface I again explored using recycled sodium silicate (see ‘Mineral Binders’ section).
Bio Binders
TMW introduced us to a range of bio-based polymers that could be used as binders. I had the most success with sodium alginate, extracted from seaweed cell walls, largely because it doesn’t require heating to use. Ultimately I kept returning to the idea of creating a material with clay-like plasticity—something hand-moldable that would set hard as it dried.
I trialled several different mixes of recycled clay with sodium alginate. They dried to a hard, plastic-like material, but with significant shrinkage and warping. To counter this, I began looking for natural fibres to stabilise the mix.
This led me to coffee chaff—the papery husk of roasted coffee beans—and to a conversation with Marcus Reading at North Star, a Leeds-based roastery. I began testing various combinations of FCC, sodium alginate, and chaff. Thanks to the chaff’s fineness and absorbency, the right mix had good plasticity and could be pressed into moulds. Once dry, it formed a hard, lightweight, cork-like material.
To progress this material I would like to refine the binder:clay:chaff ratio to improve workability, and test the materials thermal and acoustic insulation properties. I would also trial introducing a secondary mineral binder to increase strength and boost alkalinity that would suppress mould growth during drying.
This was a shift into organic materials from my usual mineral and clay based work. Seaweed cultivation, like hemp farming, is effective at sequestering carbon, and is also beneficial to water quality (Duarte et al. 2017). Meanwhile, North Star produces about 1,800 kg of coffee chaff per year (1.5% of the mass of coffee roasted). Though a small percentage, when scaled to an industry that roasts 10 million tonnes of coffee annually(ICO, 2021), chaff represents a significant waste stream—one that, if sent to landfill, contributes to methane emissions - a more potent greenhouse gas than carbon dioxide.
Mineral Binders
After facing issues with mould, slow drying times, and limited access to sodium alginate within my Yorkshire materials catchment, I returned to the waste materials I had on hand. After listening to the Architects’ Journal: Climate Champions podcast series on materials, and researching the environmental impact of Portland cement (responsible for approximately 8 % of global CO2 emissions), I became interested in alternative cementitious materials. Examples included pozzalon based Roman cement, alkali-activated materials (AAMs) and Geopolymers popularised by the work of Joseph Davidovits (e.g. Geopolymer Chemistry and Applications, 5th Edition 2020).
AAM’s combine aluminosilicate-rich materials with alkaline solutions (typically sodium silicate) to form hard, stone-like sodium aluminosilicate composites. Unlike Portland cement, they don’t require the high-temperature burning of limestone, making them a lower-carbon alternative (Singh & Middendorf, 2020).
This intrigued me, as I already had an aluminosilicate-rich material—FCC (which a University of Leeds analysis showed to be primarily kaolin - Dhandapani & Black, 2025). Sodium silicate was also familiar to me from ceramics, where it is used as a deflocculant. I began experimenting with FCC, wood ash, and commercial sodium silicate. These mixes hardened into dense, concrete-like materials, enough of a success to prompt further exploration.
I found that most commercially available sodium silicate was still very energy intensive to produce requiring the melting of sodium carbonate and silicone dioxide in a blast furnace between 1200°C and 1400°C. Researching alternative silica sources for sodium silicate, I came across a 2019 paper from Queen’s University Belfast (Vinai & Soutsos, 2019) that described a low-temperature (150–330 °C) method to produce sodium silicate using waste glass and sodium hydroxide. I returned to the finely ground glass silt from CT Glass in Bradford, originally used for ceramic glaze testing, and attempted to replicate the process—hoping to avoid the need for a ball mill due to the silt’s particle size.
I had some success in creating a thick sodium silicate gel that functioned as a strong adhesive and binder, however there were some issues with efflorescence from excess sodium. Achieving the right balance between sodium hydroxide and glass was a challenge, and I suspect further grinding or washing of the CT Glass waste would help refine the material.
The process shows promise: Innovate UK and the UKRI Transforming Foundation Industries Challenge funded trials with Re-Gen Group in Belfast, who are now working with UK manufacturers to scale up the use of recycled sodium silicate (GUITAR project, 2021) . This sets a clear precedent for its viability. With abundant supplies of residual waste glass (RWG) and FCC, there is strong potential to develop a castable, water-resistant, cement-like material.
Looking more widely at glass - although technically 100% recyclable, only about 73% of UK glass is actually recycled (DEFRA, 2021), with around 623,000 tonnes annually diverted to aggregate fill, or other downstream applications (DEFRA, 2023). Certain types of glass, like that from buildings, are rarely recycled and often end up in landfill - along with the glass cutting and polishing silt from companies like CT Glass. Estimates suggest over 200,000 tonnes of glass are landfilled annually, highlighting a clear opportunity for recovery and reuse in AAMs.
Built around recycled clay from Yorkshire-sourced CDE waste this research project has explored a number of new material pathways for the material. A key resource has been the WYCA Waste to Resources network which gave me the framework to establish a number of the connections required to access the input materials for my various tests.
Now that I have outlined potential new pathways for regional secondary waste materials, I feel this is where a second stage of a Waste to Resources, or NISP like program could prove invaluable. Interesting materials research, coming from cross disciplinary fields and collaborative projects is increasingly coming out of art schools, and industry. Yet many projects fall down where they cannot progress through the refinement, testing and certification stages necessary to turn nascent ideas into new low carbon, waste based materials that can have real impact. My feeling is that a government or independently backed program could provide a secondary networking stage to something like Waste to Resources. Designers and researchers with new materials and products could be connected with testing labs, policy makers, universities and business incubators. This builds on my belief that interdisciplinary collaboration is vital both in generating new ideas and turning them into reality.
Key ideas and materials for refinement
1. Creating low fire vitreous ceramics using regional recycled clay from CDE and waste glass
2. Using bio material additives with unfired recycled clay to increase carbon sequestration
3. Creating stronger earth bound materials using high pressure hydraulic presses removing energy intensive firing processes.
4. Creating Alkali Activated Materials using regional recycled clay and recycled sodium silicate as a portland cement alternative
5. Refining and scaling a process for turning waste glass silt into recycled sodium silicate
Thanks and Resources
Supporters
With thanks to all the organisations and individuals below who made this research project possible.
Rebecca Catterall, Director at Sunken Studio
Bonnie Hvillum, Rita Trindade, Alberte Holmø Bojesen, Sarmite Polakova, Benedetta Pompili at The Material Way
Isaac Lassey, WYCA Waste to Resources
Steven Ogden, Director at Green Gain
Steve Crossland, Technical Manager at Mone Bros
Chris Harney, Director at Bingley Stone
Marcus Reading, Head of Roastery Operations, North Star
Anna Thomason and Stephen Vickerman at CT Glass
East Yorkshire Hemp
And for your Time, Knowledge and Advice:
Christian Gäth, Researcher at Bauhaus Earth
Rowland Keable - CEO at Earth Building UK and Ireland (EBUKI)
Claire Bailey, Clay Researcher at British Ceramics Biennial
Sarah Howard, author of Circular Ceramics, co-founder of Golden Earth Studio
James Moir and Mark Gronnow, at the Biorenewables Development Centre York
Fenna Kosfeld, Artist and Material Designer
References
DEFRA UK, Statistics on Waste Report, September 2024 (https://tinyurl.com/mtbfnkre)
Buckingham S & Theobald K, Local Environmental Sustainability, CRC Press, 2003
Dhandapani Y & Black L, Characterisation of washplant waste, University of Leeds, 2025
S Howard, Circular Ceramics, 2023
Material Cultures, Circular and Bio-based construction in the North East and Yorkshire, 2021
Material Cultures, Material Reform: Building for a Post-Carbon Future, MACK 2024
Duarte C, Wu J, Xiao X, Bruhn A, Krause-Jensen D, Can Seaweed Farming Play a Role in Climate Change Mitigation and Adaptation?, Frontiers in Marine Science, 2017
ICO. Coffee Market Report—June 2021; International Coffee Organization (ICO): London, UK, 2021.
Kanokthip P, Peerawat W, Worapon K, Aerwadee P,Kulapa K, et al.. Upcycling Coffee Waste: Key Industrial Activities for Advancing Circular Economy and Overcoming Commercialization Challenges. Processes, 2024, 12, 2851
Davidovits J, Geopolymer Chemistry and Applications, 5th Edition, 2020
Müller P, Basic Geopolymer Formulations, 2020
Singh N.B , Middendorf B, Geopolymers as an alternative to Portland cement: An overview, Construction and Building Materials, 2020
Vinai R & Soutsos M, Production of sodium silicate powder from waste glass cullet for alkali activation of alternative binders. Cement and Concrete Research, 2019
McCloskey D Transforming waste glass to sodium silicate; an activator for cement-free binders and concrete products, Doctoral Thesis, Queen’s University Belfast, 2025 (https://tinyurl.com/2xm3ykhs)
Glass cUllet conversIon To wAteRglass (GUITAR)”, funded by Innovate UK, under competition call “ISCF Transforming foundation industries: Building a resilient recovery”, 2021 (https://tinyurl.com/6wsfw5sr)
Resources
I have come across a lot of great material in my research, a few not listed explicitly in my references I would like to signpost here.
Architects Journal: Climate Champions Podcast, series on Materials (https://www.architectsjournal.co.uk/podcasts)
Material Matters Podcast (https://materialmatters.design/Podcast)
De Kiln Bio, TED talk (https://www.youtube.com/watch?v=iFDJqAvH-nQ)
Talking Rubbish Podcast (https://www.talkingrubbishpodcast.com/)
Oxman N, Age of Entanglement, Journal of Design and Science, 2016 (https://doi.org/10.21428/7e0583ad)