The improvement of the energy efficiency of a building is often one of the reasons for the renovation of building facades. During such renovations, the energy efficiency is usually improved by increasing the thickness of insulation layer. The increased insulation layer increases the overall thickness of the wall, and to compensate for that, a new thin façade material is often sought. As a result, plastering has gained more and more popularity recently. However, especially in the case of thick plastering, a plaster mesh is often used to fix a layer of material, and this paper investigates the effect of the mesh on radio signal attenuation. This study shows that the plastering mesh significantly increases the overall wall attenuation, especially at lower frequencies used by mobile networks. The attenuation caused by the mesh is frequency dependent and decreases with increasing frequency. The attenuation behavior is entirely determined by the mesh size of the mesh.