Protecting earthen heritage using a green strategy: a study about natural water repellents

Using earth as a construction material is an ancient technique that can be found around the world in monumental and vernacular architecture. Earthen heritage is also associated with maintenance techniques employing natural and local products still being used in some countries. Having those methods as a background, this paper proposes to adopt a green conservation strategy and a scientific approach, learning from traditional procedures to apply on earthen heritage. In the present research, three natural products – arabic gum, linseed oil and beeswax – were studied in terms of efficiency with adobe specimens, by means of non-destructive tests (colorimetry and water absorption). The obtained data shows promising results regarding the use of natural products as an alternative for earthen heritage protection.