This article describes a study conducted to determine the ideal both traditional and stabilized composition of adobe as a building material, and to further refine an appropriate choice of coating composition for extended durability of these constructions in adobe: choose the suitable coating that fits the most with its substrate. The constructions in Z’gueg El Hadjadj [Laghouat town, Algeria] consist of adobe walls but also plaster that serves as a coating for these brick walls. The degradation phenomena of the building are considered in the adobe-coated couple, and consequently in the suitability of their compositions. The compatibility of plasters with adobes remains a major factor in the restoration and conservation of earthen constructions. This paper examines the results of the experimental characterization of the behavior of coated bricks, which consists of studying in the laboratory the water resistance: the drying-wetting test and the capillary rise test, as well as the complementary accelerated aging test: the abrasion test. These tests will be supplemented by another test, that of the adhesion, to see the compatibility of the coatings with their supports. The results, compared below, led to the conclusion that for capillary absorption and adhesion tests, a homogeneous coating in 3 layers could give more conclusive results. The drying-wetting test is recommended especially for bulk and surface treated samples.