Trenchless Rehabilitation

Standard BNQ 1809-400
Trenchless Rehabilitation - Water and Sewer Pipes

Municipal water and sewer systems must be replaced when they reach the end of their useful life. Replacement techniques exist that do not use the conventional open trench replacement method. These techniques are beneficial because they do not require that roads be dug up.

These techniques are called trenchless rehabilitation techniques. They are used to rehabilitate the insides of existing pipes.

The BNQ 1809-400 specification presents three rehabilitation methods:

• spraying a coating inside water pipes;
• lining water pipes by inserting a sheath soaked with thermosetting resin into the existing pipe;
• lining sewer pipes by inserting a sheath soaked with thermosetting resin into the existing pipe.

The first part of the specification proposes administrative clauses specific to this kind of construction work. The specification may be used in municipal invitations to tender, and its purpose is to standardize practices in this field. It provides a framework for the performance of construction work by dealing with the performance of structures. It has been developed for use by cities and municipalities of all sizes.