Influence of mortar coating thickness on the acoustic performance of ceramic block masonry

Abstract After the publication of NBR 15575 (ABNT, 2013a) concern with the performance of residential buildings has grown markedly, leading companies to evaluate and adjust construction systems and materials in order to meet the requirements. One of the requirements is acoustic design, due to the powerful and complex sound sources. The aim of this study is to analyse the influence of the thickness of stabilised mortar coatings applied to masonry made with two types of ceramic blocks, with variation in the internal and external mortar thicknesses, verifying the relation between mass increase, the insulation curve and the weighted sound reduction index (Rw). The tests were performed in a laboratory environment, following the requirements of ISO 10140-2 (INTERNATIONAL..., 2010b). The tests demonstrated that there was a correlation between the thickness of the coating and the acoustic performance, resulting in the reduction of raw materials, costs and dead weight of the building. They also showed that an increase of 5 cm in the mortar coating resulted in an increase of up to 7 dB in sound insulation between rooms.