part of the strip bending while a part 34 u2033 of the balancing layer is kept as a reinforcing layer for the strip 6 this embodiment is particularly suitable when the balancing layer 34 is composed of different layers with different properties the outer layer can for example be made of melamine and decoration paper while the inner layer can be made of phenol and kraft paper various plastic materials can also be used with various types of fibre reinforcement partial removal of layers can of course be combined with one or more grooves of different depths and widths under the entire joint system p l the working from the rear side can also be adapted in order to increase the flexibility of the strip in connection with angling and snap action two main principles for reducing or eliminating strip bending have now been described namely a modifying the balancing layer within the entire area p or parts thereof and b modifying the joint geometry itself with a reduced tongue groove depth and a special design of the inner part of the tongue groove in combination these two main principles are usable separately to reduce the strip bending problem but preferably in combination according to the invention these two basic principles can also be combined with further modifications of the joint geometry c which are characterized in that the strip is made narrow preferably less than 1 3 times the floor thickness the inclination of the locking surface is at least 45 degrees the height of the locking element exceeds 0 1 times the floor thickness and is less than.