A clip suitable for mounting cementitious boards to a frame, said clip comprising, • A sheet having a front surface and a substantially flat back surface, said sheet comprising only one aperture for receiving a fastener; • At least first, second and third hook-shaped carrying means (21, 23, 25), contacting said front surface of said sheet and standing in front of said front surface; • Said aperture and said first and second hook-shaped carrying means (21, 23) defining an axis being parallel to said back surface, said axis coinciding with said aperture and the point on said front surface being at minimum distance to but equidistant to said first and second hook-shaped carrying means; • Said sheet comprising at least two bulges (70, 72) at its front surface provided in a direction parallel to the mounting direction of the board in the clip and substantially parallel to said axis, and being located at opposite sides of said aperture between said first and second hook-shaped carrying means (21, 23, 25), characterized in that said sheet comprises attached to said front surface at least one rib having a thickness of between about 0.5 and about 2mm, said rib being perpendicular to said axis and extending from a first point of the front surface at one side of said axis to a second point of the front surface at the other side of the axis and said rib being attached to the front surface of the sheet, the sheet being uninterrupted along said rib. • A sheet having a front surface and a substantially flat back surface, said sheet comprising only one aperture for receiving a fastener; • At least first, second and third hook-shaped carrying means (21, 23, 25), contacting said front surface of said sheet and standing in front of said front surface; • Said aperture and said first and second hook-shaped carrying means (21, 23) defining an axis being parallel to said back surface, said axis coinciding with said aperture and the point on said front surface being at minimum distance to but equidistant to said first and second hook-shaped carrying means; • Said sheet comprising at least two bulges (70, 72) at its front surface provided in a direction parallel to the mounting direction of the board in the clip and substantially parallel to said axis, and being located at opposite sides of said aperture between said first and second hook-shaped carrying means (21, 23, 25), characterized in that said sheet comprises attached to said front surface at least one rib having a thickness of between about 0.5 and about 2mm, said rib being perpendicular to said axis and extending from a first point of the front surface at one side of said axis to a second point of the front surface at the other side of the axis and said rib being attached to the front surface of the sheet, the sheet being uninterrupted along said rib. • Said sheet comprising at least two bulges (70, 72) at its front surface provided in a direction parallel to the mounting direction of the board in the clip and substantially parallel to said axis, and being located at opposite sides of said aperture between said first and second hook-shaped carrying means (21, 23, 25), characterized in that said sheet comprises attached to said front surface at least one rib having a thickness of between about 0.5 and about 2mm, said rib being perpendicular to said axis and extending from a first point of the front surface at one side of said axis to a second point of the front surface at the other side of the axis and said rib being attached to the front surface of the sheet, the sheet being uninterrupted along said rib.