Renewal of Deteriorated Sewers – What Can and Can't be lined?

Rehabilitation of deteriorated sewers by structural lining has for some time been mainstream technology in the water industry. Advances have seen capabilities reach the stage where liners can be installed in applications which only a few years ago would have been too difficult or impossible. This applies to the type of sewers that can be lined and the circumstances where lining can take place.

Advances have been in the technologies that can prepare deteriorated sewers for lining as well as technologies for installing the liners under the widest range of conditions.

This paper will focus on the decisions that need to be made to determine whether a deteriorated sewer is suitable for lining or whether other options would be necessary.

A deteriorated sewer may have one or a combination of defects including deformations, joint displacements, partial collapses, root intrusions, intruding junctions or heavy infiltration. The sewer may be partly filled with rubble or debris. It may be on a steep grade, have bends or may be carrying fast flowing sewage.

The paper will detail the limits to these conditions which Interflow considers would make the sewer suitable for structural lining. Mostly those limits have been determined by Interflow’s 20 years of experience as Australasia’s largest specialist sewer lining contractor.

Technology to prepare sewers for lining has also advanced and this paper will address some of the latest and quite ingenious solutions available for the widest range of conditions.

With structural lining considered to be equivalent to sewer renewal, with an expected life at least equal to a new sewer, every effort should be made to allow it to be undertaken successfully.