In this work a Finite Fracture Mechanics approach for predicting the load causing delamination along an interface of adhesive lap joints is presented. Beside the fact that the procedure used is general, the details are given for double lap joint and balanced single lap joint configurations. For both geometries the failure load is predicted and compared with the solution given by other approaches such as the Linear Elastic Fracture Mechanics and Maximum Shear Stress Criterion. Regarding the double lap joint, a comparison with the the widely-spread Cohesive Crack Model has been performed and the results found are almost coincident. This ensures that, for the study of the critical load, the used approach gives reliable predictions and, due to his simpleness, is advantageous respect to the more complex Cohesive Crack Model.