[Purpose] concrete mortar when it is desired to not dropped from the ice tray of construction related fields is transmitted to an human than it comes to be long, the plywood period is improved and the user' s dissatisfaction to wake up and surface paint generated by pressurizing is maintained for being. [Configured] plastic plate (1) laminated wood for embedded in an internal (2) with a regular interval to surface many synthetic resin shovel' s drilled holes (3 ' ) plywood this wood as a pierced are (2) body into heat heating after five or synthetic resin the protein complex from a synthetic resin shovel' s drilled holes (3' ) than that of conventional high-plastic plate in through (1) plane reacts with hot water with swelling the bottom a blocking effect. [Effect] providing complete rot due to moisture in an enclosed space, to prevent, due to moisture wood occurs are improved and the user' s dissatisfaction is unlike plywood. real estate can be conserved as the long clean.