While we had to replace the French drain on this property we found a surprise. Part of the front foundation was made of stone and threatened to collapse. We had to strengthen it by building a concrete form. We used a more liquid concrete than usual to ensure that the concrete penetrated well into the foundation faults. Once repaired, we were able to waterproof the formwork with an elastomeric membrane and install the French drain. All this was done very quickly and the customers were able to find their property in order quickly.