Sewer Rehabilitation

The Drain Hunter was one of the first drainage contractors in the Hunter to adopt trenchless sewer replacement ,or 'no-dig technology', and is now a market leader in sewer renovation and rehabilitation using this method. Our specialist division often trials new materials and techniques and works closely with international manufacturers and industry bodies. 

Trenchless explained

‘Trenchless’, ‘no-dig’ or ‘relining’ is simply the fastest and most cost-effective way to repair a damaged drain or sewer, and causes the least disruption. As a result, it is also considered to be the most environmentally and financially favourable solution. Also known as CIPP (Cured-In-Place Pipe), it is the established form of repair for dilapidated infrastructure assets. The technique involves inserting a liner impregnated with a special resin into the sewer or drain. As the liner is inserted into the pipe, it is turned inside out and forced through using water or air pressure. The material then bonds to the inside of the pipe and the resin cures or hardens, effectively creating a new pipe within the pipe and restoring the integrity of the drain or sewer.


Each lining project is a bespoke design. That is to say that each project is individually designed to suit each circumstance. Decisions about the type of liner, resin, curing method and re-opening works are planned meticulously according to the specific criteria involved: diameter, length, type of pipe, overpumping requirements, access points, condition of drain, timescales, working area, cost, etc.

From big to small

Trenchless sewer replacement can be carried out on pipes from just 100mm diameter up to 2.5-metre culverts and, depending on access and logistical considerations, in single lengths or in a series of shorter, overlapping liners. These patch liners can be installed in pipes as small as 100mm diameter or as big as 1.2 metres.

Full relines

When renovating a full length of sewer by trenchless methods, the lining material is a concentric composite felt tube. Each one is commissioned individually for its project and delivered to our production facility, where the outer skin is manually impregnated using a specified resin. Once the liner has been installed (by inversion) into the pipe, the resin is cured either by heat (hot water or steam) or by ambient temperatures. That done, robotic cutting equipment is employed to open up any lateral connections before the pipe is re-commissioned.

And the very latest in trenchless technology: Ultra Violet

The Drain Hunter's UV liner is an innovative and bespoke fibre-glass product and installation technique. It’s fast: using UV (ultra violet) light, the lining will cure in less than 1-metre per minute.  And it’s durable: once cured the UV lining has a design life of 120 years.


Spot or patch liners are the perfect solution to localised cracks, fractures, root ingress, open or displaced joints or holes. These liners are generally made from a fibre-glass matrix and positioned using an inflatable packer. It’s a quick and cost-effective way to repair smaller, troublesome areas which could, potentially, become major issues if left untreated.

 For more information call us on 02 4915 7348 or click here to make an enquiry.