Rivestop is a patented elastic rivet with an internal mechanical waterproofing system specifically designed to SEAL hermetically the formwork holes formed by the removal of a taper tie rod or pass through tie sleeve or tube bushing on concrete walls. Rivestop expands inside any formwork hole approximately 50% of its original diameter, exerting force against the walls of the hole, thus sealing it completely. The mechanical system is activated with a Riveter with uniform and controlled pressure. Once the pin of the rivet breaks off, the Rivestop is installed. No human factor is involved.