If a cistern has leaked, the possibility of repairing it depends on the material. While a plastic cistern has a leak, sealing is no longer possible in many cases. There are some welding processes that can be used to seal the plastic bodies, but they have a limited shelf life. In addition, a complete and therefore expensive expansion of the cistern is required.
If the concrete cistern has become leaky, sealing can in most cases be carried out without any problems. The cistern water must be pumped out completely for prior cleaning.
The cleaned interior is completely re-sealed with sealing slurry according to the manufacturer's instructions. When sealing the concrete cistern, a waterproof and at the same time breathable layer of mud is applied to the sole and to the inner walls of the. Sealing agents such as acrylic varnishes should be avoided.