Evaluation of Compressed Lime Plaster tadelakt as a Protective Covering for Earth Structures

Abstract

If we observe popular constructive traditions, we could obtain solutions for our current construction necessities that require less use of the limited resources available. An example of these traditions is tadelakt, a historical Moroccan coating created 2,000 years ago and whose name, translated from the Arabic means, “rubbing”; it is based on highly hydraulic lime from the hills surrounding Marrakech, mineral pigments and vegetable soap. It was discovered by accident, when people realized that by circular motions of a stone on a lime plaster it could be obtained as a water resistance finish, this is why it has been used in spaces and surfaces subjected to constant contact with water and humidity, for example the interior of the hammams (public baths), ancient earth constructions currently located in Morocco. Other benefits of tadelakt are its high durability and its possibility of returning to nature without negative consequences for the environment. The objective of this work is to evaluate quantitatively the protective properties of the tadelakt made with easy available materials (similar to the originals) for earth structures. This was defined through permeability tests made of adobe samples covered with the tadelakt plaster adapted to México, determining that this technique is a proper option to protect and conserve historical buildings made of earth due to the low permeability of the finish that protects the earth of the direct contact with water and at the same time allows the subtract to performs its function of temperature and humidity exchange between inside and outside.