Abstract: An auxiliary device for laying flexible wall and floor coverings includes an elongated angle plate having a supporting surface for the material to be cut to size and a pressure strip having a lower pressure surface of approximately the same length as the supporting surface and which has a cross-sectional profile which is configured to complement the profile of the supporting surface. The supporting surface has at one end a wedge-shaped end portion, the outer edge of which defines a supporting edge, and a cutting edge defined at its opposite end, which edges lie in a base plane. The angle plate also includes a part having a locating edge disposed parallel to the cutting edge. The angle plate in cross-sections lies substantially within an imaginary triangle, with its cutting edge, supporting edge and locating edge passing through one corner of the triangle.