PURPOSE: To improve waterproof performance and slip preventing performance by applying the second layer of intermediate hardness polyurethane system through a mesh-state sheet to upper surfaces of the first layer of polyurethane system, adhesively attached to a floor surface of concrete; and forming irregular streaks on a surface.

CONSTITUTION: An urethane adhesive 2 is applied to a concrete floor surface 1, and a foam polyethylene layer 3, in which many perforated holes 4 are formed, is connected to this agent 2. Next, on top of the layer 3, the first layer 5 of two-component type liquid-state polyurethane, relatively soft with large elongation percentage, is applied. Then after the layer 5 is hardened, a mesh- shaped sheet 6 of fishing net or the like is placed, further the second layer 7 of two-component type intermediate hardness liquid-state polyurethane, excellent in wearing resistance and chemical resistance, is applied and hardened. While elastic rubber dust may be dispersed in the layer 5, or the provision of the layer 3 may be eliminated. In this way, waterproof and sound-insulating performance can be improved further being possible to prevent a walking slip while being possible to facilitate execution work.