BBRI is performing a research program in order to evaluate the technique of the ‘gluing' of units for veneer walls. Final aims are to provide a full range of necessary and accurate information to the sector via a Technical Report and to give a basis for a suitable guideline for certification. This two-parts paper presents only the results in relation with the bond strength. After having discussed the available test methods characterizing the bond strength in the first part of the paper (1/2), part (2/2) presents the results of mechanical tests on clay units/adhesive mortars combinations performed on a wide range of material properties. Moreover, microscopic analyses were performed. The evaluation of the durability was done by mean of frost resistance tests. The influences of the material properties are discussed. In general, we can conclude that on all the tested combinations, no important problem related to performance has been detected (initial bond strength, frost resistance).