When the single side slope length is less than 12M, the roof may not be provided with transverse joints; When the slope length of one side is greater than 12M, transverse joints shall be set between color steel plates. The transverse joints are generally overlapped along the water. In order to ensure the waterproof effect, a certain overlapping length must be met, and the overlapping length is related to the roof slope. When the slope is less than or equal to 1 / 10, it should generally not be less than 300mm; When the slope is greater than 1 / 10, it shall not be less than 200mm generally, and the height of the lap joint shall be staggered, and the waterproof sealant strip shall be pasted between the upper and lower layers of plates.

这样不仅可有效防止渗水，还可防止钢板切口处氧化锈蚀。同时应注意搭接处一般采用自攻螺钉固定在波峰位置。若设置在波谷上，必须要有可靠的防水措施。

This can not only effectively prevent water seepage, but also prevent oxidation and corrosion at the notch of the steel plate. At the same time, it should be noted that the lap joint is generally fixed at the wave crest position with self tapping screws. If it is set on the trough, reliable waterproof measures must be taken.

屋面低波彩钢板用连接件直接与檩条连接，每波或隔一个波设置一个，但搭接波处必须设置连接件。屋面高波彩钢板用连接件与固定支架连接，每波设置一个。

The roof low wave color steel plate is directly connected with the purlin with connectors, one for each wave or every other wave, but connectors must be set at the overlapping wave. The roof high wave color steel plate is connected with the fixed support with connectors, one for each wave.

另一种上下板连接方法是压板挤紧法，在两块彩钢板的上面和下面各设一块与彩钢板板型相同的镀锌钢板，两板间设防水密封条，用紧固螺栓将其紧密挤压连接在一起。为避免板的长向搭接处引起漏水，也可将压型板生产设备运现场安装，轧制从屋脊到檐口的整张屋面板，边轧制边安装，无需长向搭接，避免不必要的渗漏。

Another method for connecting the upper and lower plates is the pressing plate extrusion method. A galvanized steel plate with the same plate type as the color steel plate is set above and below the two color steel plates, and a waterproof sealing strip is set between the two plates, which are tightly extruded and connected together with fastening bolts. In order to avoid water leakage at the long lap joint of the plate, the profiled plate production equipment can also be transported to the site for installation. The whole roof panel from the ridge to the cornice can be rolled and installed while rolling. There is no need for long lap joint to avoid unnecessary leakage.

通常情况下，选用长板不搭接好，但在实际工程中发现，板过长时，由于温度影响板的伸缩会引起螺孔扩张而产生渗漏;同时，由于板过长，在制造、运输或施工过程中易损伤涂层，影响质量。

In general, it is not good to select long plates, but it is found in practical engineering that when the plate is too long, the expansion of screw holes will be caused by the expansion of screw holes due to the influence of temperature; At the same time, because the plate is too long, it is easy to damage the coating and affect the quality during manufacturing, transportation or construction.