When covering the silo film, it is important that the film is completely sealed at the edges. This is achieved by sandbags which are lined up seamlessly. Due to the special design of the article Slep Tandem Bag, it keeps the position stable. The weight of the individual bag plays a subordinate role in sealing and the practical test shows that a weight of approx. 12 kg is easily sufficient. Summing up the weight on a silo, one get easily into the ton range. A multiple of it is often even superfluous.