Roof tiles damages after 30 years in use

Durability of clay roof tiles depends on different factors. Some damages of roof tiles are result of raw material composition and technology process, and some are result of different environmental conditions. A few decades ago, production process itself was not so sophisticated as nowadays. Typical damages of roof tiles can develop from soluble salts which result in appearance of stains, peeling and powder occurrence. This type of damages usually appears on lower side of roof tiles and can be very undesirable taking into consideration hygienic and aesthetic aspects. Likewise, lime grains from raw material can also cause damages like cracking and spalling. Moreover, one of the serious problems that can appear in roof tile is frost damage that depends on porosity and water absorbing capacity of roof tile. In the paper, typical damages of 30 years old roof tiles observed on several roof trusses are presented. From each site, a certain number of roof tiles were also taken for laboratory investigation. Laboratory testing was conducted to explore the various degradation mechanisms.