Abstract: A gradient insulation screw (1) for adjustable fastening of a roofing membrane (2) on a substrate, in particular a steel sheet (3), the gradient insulation screw (1) comprising a drilling tip (4) with a first direction of rotation; following the drilling tip (4), an assembly thread (7) with a second direction of rotation, which differs from the first direction of rotation; following the assembly thread (7), a first thread-free region (8); following the first thread-free region (8), an adjustment thread (9) with the first direction of rotation, the outer diameter of which is greater than the outer diameter of the assembly thread (7) and the drilling tip (4); and following the adjustment thread (9), a tool holder (10) as well as a system (11) for adjustable fastening of a roofing membrane (2) on a substrate with a gradient insulation screw (1) and a holding element (12) and a method for adjustable fastening of a roofing membrane (2) on a substrate using such a system (11).