We noted signs of water infiltration on certain interior coverings of the foundation (under the stairs). Water infiltration seems to be related to foundation cracks. Tests to detect the presence of moisture were positive on walls and floor coverings.
We also observed damage and signs of excessive humidity on the basement ceiling.
The interior finishes as well as the concrete slab and the foundation must be dry, sound and without stains. Humidity and water facilitate the proliferation of rot and mold, which constitutes a health risk for the occupants.
We recommend that you immediately appoint a specialist contractor to carry out an exhaustive expertise in order to determine the origin of these situations and validate the solutions.