This study is an experimental investigation about the thermal properties of adhesive before and after the mixing with fine sand. The results show that such an addition significantly improves the thermal characteristics, such as: reducing the initial and the final shrinkage, reducing the heat of the reaction, coefficient of linear expansion, and the coefficient of the thermal conductivity. Also, such an addition leads to a reduction in the adhesive cost and a small increase in the compressive strength and the modulus of rupture. The ratio of the fine sand to the adhesive equal to 1 is considered the best in terms of the cost reduction, maintaining workability, as well as maintaining the mechanical properties.