A customer called and told us that she found that the humidity level was high in the basement and that sometimes when it was raining she had water in some places on the basement floor. We proceeded to an excavation to inspect the state of the French drain. Unfortunately, the French drain was installed ON the footing … Nothing good to do with this! The drain goes next to the footing since its primary purpose is to prevent soil water from passing over the footing. With such an installation, the soil water is continually in contact with the inner concrete slab and above the footing.
Unfortunately for the customer the only possible solution is to replace this one by a good french drain well installed. At the same time we install an elastomeric membrane on the foundation as well as insulation.