This research focuses on the weathering and conservation of sedimentary rocks by surface modification. More specifically, the focus will be on how salt crystallization is affected by surface modification of minerals in porous sedimentary rocks. Attention will be paid on the one hand to changes in surface roughness and how this plays a role in salt crystallization and on the other hand to changes in contact angle of water on the minerals under investigation. These changes can be controlled by the application of external chemicals but also by the application of bacteria. Changes in salt crystallization can affect fluid transport within a rock as well as the durability of the materials. The durability of the treatments themselves, must also be investigated and for this purpose these treated materials will be exposed to accelerated weathering tests.  By combining all these factors, we aim to better understand the mechanisms that affect the stability and preservation of sedimentary rocks, with the goal of developing more effective conservation methods.