The longevity of Fabsil waterproofing treatment can vary depending on factors such as usage, exposure to the elements, and the specific product used. In general, Fabsil treatments can last for several months to a year or more under typical conditions. However, it's essential to reapply the treatment periodically, especially after heavy use or exposure to harsh weather conditions, to maintain optimal waterproofing performance. Additionally, following the manufacturer's instructions for application and care can help prolong the effectiveness of the treatment.