Enhancing insulation properties of building stones

Recently, using rocks, especially limestone, in the facades of buildings has become pervasive due to its characteristics such as hardness, insulation, and aesthetic view. Meanwhile, interest in building insulation materials has been increased to prevent indoor humidity of building walls and provide thermal comfort with less energy usage. As a result, many insulation materials have recently emerged, including the coating material used to isolate the stone facades after being built. This paper aims to evaluate the effect of the silicon coating material on the insulation properties, represented by water absorption and thermal conductivity, on limestone building stones. This material showed positive results in reducing the stone’s absorption of water, reducing the absorption up to 53%, where the absorption capacity decreases with increasing the thickness of the coating material on the rock’s surface. Correlations between thermal conductivity and rock’s porosity, density, and hardness were also presented. The results showed that the effect of the coating material on the thermal conductivity varied according to the hardness of the stones.