One of the key deterioration factors for porous inorganic building materials are soluble salts. To be able to remediate or mitigate this problem it is fundamental to understand the principal processes governing their behavior. While the actual mechanisms involved in these processes are still under study, the deterioration can be mitigated or remediated by the long practical experience gained in the field. The paper aims to provide an overview of the basic principles that rule the interaction of salts with the porous inorganic material. Understanding these will allow the development of appropriate procedures to control the deterioration process.