Abstract: Powerhouses built in northeastern region always suffer sever cold climate, how to effectively deal with the problems of breaking waterproof material owing to icing at powerhouse building roof, there have been no effective methods to be referred. Based on a large qualities of data analysis and investigation and filed experiments, a new waterproof technique for building roof available for cold regions has been summarized. It is detailed in this paper with the application case of Lotus hydropower station.?