Rammed earth is a proven building material. For more than 6,000 years and in virtually every region of the world, rammed earth has been used to build every type of structure, from house to monument to fortress – a surprising number of which still exist today.
Many of the great archeological remains of the Middle East and Africa were constructed with rammed earth, and several areas of China’s Great Wall were also built this way. Closer to home, this form of building with earth was originally introduced to Europe by the Romans, and can be found in structures spanning from Italy to here in England – most commonly in the chalk belt of Hampshire.
In parts of France, especially the Rhône Valley, many buildings are made of pisé de terre, or rammed earth. In the late 1700s, French and German immigrants brought this building technique to America. Many grand homes constructed using pisé, many still in use today, were built across New York, New Jersey, Pennsylvania, and Washington, DC.
Image right: Aït Benhaddou, a historic fortified village in Morocco, made entirely out of rammed earth, adobe, clay bricks, and wood. Aït Benhaddou has been a UNESCO World Heritage Site since 1987. Photo credit Cian Fenton.
Great Wall of China, near Jiayuguan. Photo credit Carsten van Brink.
Historically, rammed earth is made by combining a precise ratio of pure mineral earth comprising clay, sand and aggregate, with a small amount of water. This mixture is then compacted into shuttered wall forms. Once the wall is completed, the wooden forms can be removed and reused. As the resulting rock-hard monolith cures, it takes on a greater crush strength than adobe brick – a predominantly North American building technique using unbaked mud bricks, that require a lengthy drying time before they can be mortared into courses to form walls.
Traditional rammed earth wall on concrete footing. Illustration by Clayworks.
“As centuries-old structures throughout the world attest, a properly designed and built earth home is likely to be standing long after most wood framed structures are in landfills. Earth building requires a special number of design considerations. Finding suitable earth for a building is important for a quality finished product. If not available on-site, it needs to be imported.”
Scott Grometer for the book ‘The Art of Natural Building’
The benefits of rammed earth construction are varied and proven. However, traditional rammed earth architecture requires many tonnes of compressed earth (normally at a width of 800mm) to create buildings with structural integrity, prohibiting its use and viability in most urban and retrofit contexts.
The incredibly thick walls of a rammed earth structure reduce usable floor space in tight sites, while integrating and retrofitting windows, doors, and services (e.g. plumbing, electrical, air-conditioning) into rammed earth walls requires special detailing and careful planning. There is also the major expense of labour costs, given the nature of the construction.
After decades of hands-on earth building and research trips around the world, Clayworks founders Adam Weismann and Katy Bryce developed our clay plasters and natural finishes – maintaining the essence and benefits of earth architecture in a contemporary, accessible way.
Clayworks Rammed Earth finishes have been developed as an answer to the complex and technical challenges of building with monolithic mass. These can be applied as an entirely customisable 7-10mm thick wall build up, suitable for all wall and construction types, revolutionising the way this natural building technique can be applied in contemporary building, delivering a cost effective and sustainable option.
Example build up of our Rammed Earth Finish. Illustration by Clayworks.
As with rammed earth construction, our finish is made from 100% natural clays, minerals, sands and coloured with natural earth pigments – a surface material able to achieve the authenticity and feel of monolithic rammed earth. Our rammed earth finish also contributes to the performance of the building fabric: softening acoustics and thermal variations, and offering moisture control and breathability.
CBRE, Glasgow. A workplace designed with biophilic principles, the space carefully considers air quality, lighting, thermal and acoustic comfort, and the use of sustainable materials. Photo credit Alex Treadway.
There are countless possible variations of colour and texture, often in response to a desire by architects and designers to replicate local geological conditions, or to evoke cultural connections from specific vernacular architecture from around the world. Global sportswear brand On recently partnered with M Moser Associates to create its new 25,000 sq ft London office.
On’s new London headquarters. Photo credit Chris Wharton.
Inspired by the geology of the River Thames Basin, our Rammed Earth finish was used throughout, carefully layered by hand to create a gradient effect that subtly lightens as it ascends, echoing the natural stratification of earth.
“We specified the Clayworks rammed earth finish after an in-depth review of several options. It offered the lowest carbon impact across material composition, transport and application. Working with a UK supplier meant we could use locally sourced clay from southern England, which supported the design concept and reduced emissions. Its natural pigments gave us freedom to match the visual intent while staying true to the raw qualities of rammed earth. It was the most sustainable choice without compromise.” Suzanne Ries, Sustainability Specialist, M Moser.
On’s new London headquarters. Photo credit Chris Wharton.
Clayworks Rammed Earth Finish represents a powerful bridge between ancient wisdom and modern performance. It allows us to re-engage with a building material that has stood the test of time, now refined to meet the demands of contemporary design and construction.
To see more of our Rammed Earth Finish projects, for technical specifications, or to request a sample, visit:
https://clay-works.com/collections/custom-finishes/rammed-earth/
