After nearly twenty years of flue gas inlet in cooling towers the formerly used epoxy-based coatings did not protect the interior concrete surfaces of cooling towers for as long as had been expected. Even on surfaces coated again in the last 10 years degradation took place and supplementary coatings were needed. Therefore certain analyses and considerations were undertaken to find new solutions to reinforce the surface protecting coatings of the cooling towers so they could be operated for another period of 25 years. The execution of this project needed new and optimized methods to plan and carry out the implementation.