It may be one of the oldest building materials, around for millennia, but clay/terracotta still has plenty of life in it yet. Annabelle Filer offers a selection of new twists on the material that promise to keep it a major player
Humans have never been particularly keen at the notion of living in a burrow, though we have evolved somehow from the cave to overground burrow. But we still don't seem to be able to get away from clay. In fact, roughly half to two thirds of the population live within a building where clay remains prominent, be it as a load-bearing element or protective skin.
One of the oldest building materials, clay is a combination of clay minerals formed by the gradual weathering of rocks, and when mixed with water it exerts a certain plasticity that endears itself to us. When fired, physical and chemical changes happen, clay becomes a ceramic and its new dexterity puts clay into the building, decorative and product arenas. But not content with remaining in a simple state, clay, depending on the composition and firing conditions, metamorphoses into earthenware or terracotta, stoneware and the resplendent porcelain.
Terracotta and clay in its unfired form are no half-baked half-breeds though. These robust products from the earth can throw shapes too, and in doing so offer a sanctuary for restoration, the eager laser a surface to 'patternate' and pigmentation a platform for expression.
Raster Engraved Terracotta
To talk about laser cutting, or rather engraving, terracotta may seem to some like playing hip-hop at a ballroom dancing class, but it appears that terracotta is cosying up with engraving. Raster engraving - a laser-etching process that can be used on an existing terracotta tile - is the esoteric equivalent to branding cattle with a hot iron, though with a far greater finesse: the terracotta tile is moving from a world heaving with tradition into one heady with new opportunities.
Cut Laser Cut is a laser-cutting agency created by a team of designers, and it is their creative leaning that has encouraged them to push boundaries, something the terracotta tile or brick can be truly grateful for. The company use CO2 lasers that can cut softer materials and engrave harder ones, such as metals and ceramics.
In effect raster engraving marks the surface and can go down to strokes almost as fine as 0.01mm, leaving a grainy, brown image or line.
The brick - one of the most universally used terracotta products worldwide - thanks to Stolen Form, is having an opportunity to be repurposed as a new desirable and collectable product. Christian Marsden, the ceramicist behind Stolen Form, is keen to present the mundane in a new light, and the brick features prominently in a number of collections.
His collaboration with UK artist Sunil Pawar, for example, sees the brick cast new with a customised gold skin. At Stolen Form the brick is exploited in a number of ways: used as a mold, painted or glazed from many angles and bonded together to form a vessel. In turn this artefact is a reminder of the versatility of terracotta. The brick, whose strength is usually in numbers, is in this instance aesthetically strong in an individual role.
Architectural Terracotta & Faience
Terracotta as a facade material proves to be a worthy opponent of stone: it is resistant to weathering and atmospheric attack, and delights in fine detail and complex curves. Shaws of Darwen is an old hand when it comes to the manufacture of architectural terracotta and faience, the highly glazed façade terracotta that is as useful for restoration as it is for new build.
Restoration is a carefully honed performance that starts with a detailed survey and finishes with a piece that has been cast using blended clays with pigmentation from metal oxides in laboratory-controlled conditions. The scope of works relies on the skills and experience at Shaws of Darwen, and it is able to factor in the role the firing plays on age and the subtle nuances of shade and colour changes softened by the weather. There may be quality controls in place and analysis carried out but, at the end of the day, Shaws of Darwen knows the world of terracotta.
One newer method employed is the use of a more liquid, slip-cast clay to produce products with thinner walls, which are less likely to contain fissures or have lamination problems. While this is not radical technology, it would seem this careful approach is typical of Shaws of Darwen. Why reinvent the wheel? All you simply need to do is steer it well.
Daniel Ogassian is a man with a refreshing take on minimalism. He considers it another form of decoration, but with fewer lines. Ogassian's tile designs in concrete and ceramic, notably terracotta, are bold, captivating and true to the materials. He is an artisan turned industrial designer who regards his tiles as clean-lined, and neither modern nor ornate.
Part of Ogassian's skill is his knowledge of production, with a MA in ceramics and 20 years in practice. His terracotta subterfuge, while not completely detracting from concrete tiles, does help shift the desire for concrete down a gear and raise terracotta up a notch in the design conscience as a material that may just start to knock concrete off its current design pedestal. Can that be a bad thing?
Founders of Clayworks Katie Bryce and Adam Weismann spent years with clay caked under their fingernails, learning to craft and use clay on a building before deciding to present the architectural community with a useful, malleable alternative: dry clay plaster with coloured pigments in a bag.
Clay plaster is not a new idea; indeed it is an ancient idea, dating back to 10,000BC. Clayworks however, has developed it into a modern format, and clay plaster is another big box ticker for the sustainability designer. It appears to empathise with the room, acting as a natural thermostat by absorbing and returning heat back to the space to help retain an ambient temperature. It is also compostable, biodegradable and non-toxic.
These naturally pigmented clay plasters may be applied to many internal wall and ceiling surfaces, from historic and eco-based substrates to the more conventional plaster. The substrates are primed with a gritty coat with a topcoat or two added using a metal trowel. The thickness of the primer and topcoats vary according to the substrate. The final finish is applied either using a plastic trowel to close the grain and produce a smooth, polished surface or a damp sponge for an open-grained, gentler look.
This article was first published in fx Magazine.