As part of this thesis, a test was made on fresh and hardened mortar mixtures aimed at preparing restoration renders. The main purpose was to prepare various compositions of mortar for restoration renders that would have the highest possible air content and water vapour permeability at adequate compressive strength. We wanted to find out how different types of binders and chemical admixtures affect these properties of mortars. Based on the given ratio between the aggregate, the binder and the admixtures, the first part of the thesis focuses on the final mixture compositions that were obtained after several attempts of adding different amounts of water to them. Superplasticizer and air entraining agent were used as chemical admixtures and as binders two different types of cement and lime were used. Research on the fresh mixtures was conducted with standardized methods of determining the flow value on the flow table, after which the density and porosity of mortar were determined. In the second part of the thesis, compressive strength and water vapour diffusion were tested on 28-day-old hardened samples. All the results obtained during the tests are given in tables and graphs.