1. Nature buckle type: it is in the form of cement asbestos corrugated tile and galvanized iron sheet tile. However, the old buckle method requires at least one flat wave distance be overlapped. For the use of color steel plate, the wave is generally large. If another half wave is overlapped when used as roof, the encomic index will be improved. Therefore, many practices adopt hte method of overlapping one wave. this kind of edge shape causes some hidden dangers in the waterproof of the panel joints of steel structure factory building. However, there are generally no problem when making walls.

2. Waterproof cavity type: a cavity of about 4mm is formed at the two buckle edges. This cavity cuts off the capillary passage by the attachment of two steel plates. At the same time, the water column in the cavity will balance the phenomenon of rainwater infiltration into the room caused by the difference between indoor and outdoor atmosphenic static pressure. This method has been applied to the section shape design of profiled plate in a new generation of steel structure workshop. This is an economical and effective method.

3. Bite type: it is divided into 180° expansion type and 360° bite type. This method uses the bite machine to bite the two overlapping edges of the plate together. The 180° bite is a non tight bite, while 360°is a tight bite, which is similar to the manual bite white iron worker, so it has a certain air tightness. This plate type is an ideal and reliable waterproof plate type, but the cost is higher than the previous ones.

4. Buckle cover plate type: two edges are symmetrically arranged, and bayonet structural edges are made on both sides. After installation, buckle the cover on it. This method uses the principle of cavity type to set the buckle cover, waterproof and reliable, but the amount of color plate is too much.