Earth mortars: a vernacular tecnology and a modern eco-efficient solution

Earth constructions have been used for millennia by humanity, with an immeasurable accumulation of knowledge to be explored. However, in the last 150 years this material has been systematically replaced by chemically altered industrial materials that are responsible for great environmental pollution, inert waste generation and irresponsible consumption of natural resources. Despite this, since the 1960’s, both academic and professional efforts have been perceived to develop more environmentally sustainable technological innovations for civil construction, seeking inspiration from past practices such as the resilient designs of Vernacular Architecture and natural building materials such as earth. Buildings with earth, as well as earth mortars, offer very advantageous properties to buildings, such as aesthetics, thermal balance, environmental comfort, noise absorption, durability and fire resistance, in addition to generating only organic and biodegradable waste. Earth mortars for laying and covering are one of the most used items in a construction and represent great importance for the durability of buildings, and can also be a weak point if they are not carried out correctly. In a country like Brazil where there is still a living tradition of building with earth, and a vast vernacular repertoire of historical heritage in demand for restoration, it is even more important to investigate the properties of earth mortars, develop new technological solutions and publish specific national technical standards to guide its use. Currently, Germany is the first and still the only country to publish a specific technical standard for the analysis of physical and mechanical properties in earth mortars, the DIN 18.947 standart, being an example for the whole world. Thus, this article aims to contribute to the consolidation of the technical and theoretical framework on the subject in Brazil. The text presents an overview of some solutions used for mortar stabilization throughout the vernacular history of construction with earth and concludes that although the materials and solutions of vernacular architecture are subject to transformations and adaptations according to the demands and technological innovations that arise with passing from time, the qualities of these materials already consecrated by the empirical vernacular tradition can justify their return and the permanence of their use.