This paper describes the experimental evaluation of the effect of using different roofing materials affecting the quality and quantity of the amount of rainwater collected and stored in the Kosice city area. The two sites that were tested were located at the TUKE (Technical University of Kosice) campus site. Two models serving as data sources were located on the roof of the University library and a third source of data was an actual school building (PK6). The results obtained were then inputted to create a simulation. This article provides a detailed analysis of the factors at play in relation to the quality of rainwater collected and drained off from the PK6 building roof, and also an evaluation of an experimental model relating to a ceramic tiled roof. The results show that both roofing materials tested are suitable for systems collecting and storing rainwater. Ceramic tiles are suitable for the purpose without any complications concerning further treatment; Ceberit needs additional treatment and disinfection. The findings shall be used to inform the next step – modelling data.