In the underground pipeline repairs, the trenchless technology or polymer “house” process technology is being used more and more frequently.

This method allows restoring underground utility systems with almost no digging works and without laying new underground pipes. The existing pipe is used as a shell or mould in which a soft and flexible fibre-material pipe impregnated with synthetic resin is laid (installed). The material is being inflated, it expands and adheres to the walls of the existing pipe. After that, they are pumped with hot steam and the material laid at high temperatures hardens.