This paper reports the results of XPS study of the chemical modi. cations that occurs at the surface of have fluorinated compounds, deposited on calcarenite specimens, after 240 h of a simulated ageing in a climatic chamber under UV radiation and thermal stress. It has been found that the modifications occurred after this ageing treatment are not dramatic, nevertheless they are revealed by XPS analysis. However, these modi. cations do not affect the values of the static contact angles which remains practically unchanged after the ageing treatment with respect to those obtained before. (C) 2008 Elsevier B.V. All rights reserved.