6. Conclusion

In this dossier, we have tried to identify the main cases of deterioration of paint coatings exposed outdoors. Only the most frequent phenomena have been mentioned. However, for the various substrates, there are many cases where several causes are combined (figure 22 ). Only a competent expert, sufficiently informed about the progress of the work and its environmental influences, will be able to explain the damage and deterioration of the various parts of the elements under consideration. He or she should also be able to suggest at least one method of repairing the damaged surface.