The use of thin marble and limestone for facade cladding has increased substantially during the last five decades. The durability of such thin slabs (often only 30 mm thick) has been assumed to be satisfactory based on centuries of successful use as a structural building stone. Nevertheless, all over the world, the long-term deformation and strength loss of some claddings have led to concerns about its safe and durable use. The detailed assessment of marble and limestone within TEAM (see also www.sp.se/building/team), is used to develop a hypothesis for the observed deterioration and to develop remedial actions. This paper considers the influence of rock and mineral properties on the behaviour of marble claddings. A selection of results is presented, illustrating the influence of properties like mineralogy, grain size and boundaries, preferred orientation and pore structure. Of the intrinsic parameters, the interlocking of the grains and the lattice preferred orientation seem to be very important influencing factors. The final evaluation of the results will be presented in 2005.