Certain types of roof system, roof systems, found primarily in the Benelux countries, do not use the type of wooden rafters and purlins commonly found elsewhere in roof construction. Self-supporting, insulating roofing elements are laid vertically instead to create a roofing framework. These elements mainly comprise thick-walled insulation held in place at the edges by wooden rafters. The conventional type of roof hook cannot be used with these roof systems as they cannot be fastened to the narrow rafters supporting the roof overhang. Kit systems comprising roof hooks hung from a tile or batten provide no alternative in such cases as these roof systems are not able to withstand load on the tiles. The new Rapid 2L roof hook system solves this problem in that it diverts the forces into the vertical wooden rafters via a specifically designed mounting kit.