from a Central European perspective, the use of salt as a construction material sounds little attractive at first sight. In periods of extended rainfall, a salt construction risks to dissolve and disappear. Combining salt with other materials is difficult, because salt is corrosive.
Salt Construction Materials Attract the Interest of Architects
And yet, salt seems to increasingly attract the interest of architects. In early 2023, Arch Daily, an architecture website published an article “Could Salt Be a Material of the Future? Innovating with Crystallized Salt Panels”. The author looks into historic and current uses of salt as a construction material, and examines its potential for future use in construction. https://www.archdaily.com/994769/could-salt-be-a-material-of-the-future-innovating-with-crystallized-salt-panels. In 2021, a similar article had appeared in “The Plan Journal” (Pungercar, Vesna & Musso, Florian. (2021). Salt as a Building Material: Current Status and Future Opportunities. The Plan Journal. 6. 10.15274). In January 2023 a book appeared on 3D printing for Construction with Alternative Materials. One of the chapters is about 3D printing with salt. https://link.springer.com/chapter/10.1007/978-3-031-09319-7_5.
Raw Salt Materials
The authors classify salt construction in 3 segments – raw salt materials, composite raw materials and processed salt materials. Raw salt materials consist of salt blocks. Several hotels in Uyuni are constructed entirely from salt blocks. Historical examples are the cities of Dallol in Ethiopia, Teghasa in Mali, and Getta in Syria, all of which are in extremely dry world regions.
Salt Composite Materials
The most prominent example for the use of a salt composite construction material is the Siwa Oasis in Western Egypt. The oasis has been known by the Karsheef block, a mixture of mud, salt and minerals. The material proved good structural characteristics and high thermal insulation under the extreme climatic conditions of the desert. (L. Rovero, U. Tonietti, F. Fratini, S. Rescic, The salt architecture in Siwa oasis – Egypt (XII–XX centuries),
Construction and Building Materials, Volume 23, Issue 7, 2009, Pages 2492-2503).
Processed Salt For Interior Decoration
More recently, processed, crystallised, or compressed salt materials are used for decorative purposes and as cladding material.
Many Reasons to use Salt in Construction – Environmental Performance is Key
A multitude of reasons speak in favor of salt construction materials. The white polycrystalline, semi-transparent material provides a unique aesthetic touch. Salt is affordable, easily available, antibacterial, resistant to fire, can store humidity and heat, and is great at reflecting and diffusing light. Certainly, most important is the unique environmental performance of salt as a building material. Crystallization from seawater has a very low carbon footprint, the material is widely available and does not need to be transported over larger distances, the material is 100% recyclable at minimal energy input, and if by-product salt from potash mining is used, it helps to avoid disposal issues.