DOUBLE STANDING SEAM
The STANDING seam technique allows the jointing of previously profiled sheets and strips, obtained by layering and folding the edges. The fastening to the substructure is made with the aid of fixed and sliding clips anchored by screws or nails. The double standing seam technique is the most versatile solution that best suits the more complex shapes that may be encountered in a roof. The minimum height of the finished seam is 23 mm, resulting from lateral bending of the sheets which, through various operations, are joined to form a double seam. Employing profiling machines and seamers for bending, each section loses about 70 mm of material; the play that is formed, equal to 3-5 mm, absorbs the transverse expansion of the sheets due to heating. The minimum roof inclination required is 5% (3 °).