Flashing is an indispensable key component in light steel and wood structure building, it can play the role of water diversion, in the building by external forces (such as: earthquake, typhoon, and other external forces under the action of the house to bear irresistible ), Different from sealant, it will leak in case of irresistible external force and lose its due effect. The design of flashing should be considered to have a certain crack resistance distance.The proper drainage characteristics will be maintained without broken.So in Europe and the United States don’t have metal flooding plate of the building is incomplete.Especially in the new isobaric rain-screen is particularly important.)