The utility model discloses a nanometer hydrophobic building external wall
brick which comprises a
brick body, a clamping block and a clamping groove are arranged on the outer side of the
brick body respectively, and water guide grooves are formed in the surface of the brick body at equal intervals. A protruding block is fixed to the side face of the clamping block, a deep groove is formed in the portion, located on the side face of the clamping groove, in the brick body, a limiting block is arranged on the inner wall of the deep groove, and a reset spring is installed between the end of the limiting block and the inner wall of the deep groove. According to the nano hydrophobic building external wall brick, a directional drainage path is formed through the design that the multiple water guide grooves are formed in the surface of the brick body, rainwater on the brick surface is rapidly guided to the bottom of an external wall, the
residence time of water on the brick surface and gaps is shortened, meanwhile, rainwater can be rapidly guided into the water guide grooves through the arranged hydrophobic rods, and the water drainage effect is improved. Accumulated water is prevented from diffusing on the brick surface, the drainage efficiency is improved, the adjacent brick bodies are quickly assembled together through the L-shaped clamping blocks and the clamping grooves, and construction is convenient.