A ready-witted selection of high-quality construction materials for walls and roofs provides greater well-being and thermal comfort for building co-owners. It also reduces energy consumption with artificial conditioning appliances. This research aimed to analyze the thermal behavior of a ceramic brick masonry prototype composed of an external coating of Portland cement mortar and an internal plaster coating with variable thickness. Tests were carried out in a thermal chamber, and the temperatures were recorded by a non-contact thermographic camera and conduction thermocouples measuring equipment. Hence, the parameters obtained were fourfold: thermal resistance, thermal capacity, thermal transmittance, and thermal delay. The four latter were calculated as per the simplified method proposed in the Brazilian specification for Thermal performance in buildings (i.e., NBR 15220-1). As a result, the thicker plaster-coated block prototype showed a minor temperature variation during the heating process. Thus, the thickness of the plaster coating possesses a direct influence on the thermal response of the brick; The thicker the coating becomes, the better the thermal performance of the structural element.