Our journey since 1936

At Interflow, we have the heart of a humble business, with the vision of something much greater: a vision that drives the growth of our people, fosters our partnerships with customers, promotes continuous improvement, and ensures the wellbeing of the communities we serve.

Throughout our journey, which spans more than eight decades, our rich heritage of innovation continues to spearhead the market, paving the way for a bright future.

Since our inception in 1936, we have carved out our place as a leader in water infrastructure. Today, we are regarded as one of Australia and New Zealand’s leading providers of trenchless pipeline solutions, specialising in the water, wastewater, stormwater and culvert sectors.

Spanning Australia and New Zealand, we work to deliver on our purpose: to improve the lives of the people we work with, the communities we serve and the environment we work in, for generations to come.

Together, we’re Creating the Future of Water.

Interflow over the years

Founded in 1936 as ‘General Constructions’

Harold Weaver founded our company in 1936 and named it General Constructions. He instilled three core values into our business: Honesty, Reliability, and Competence.

The first project undertaken was the construction of a reticulation sewer at Northbridge in Sydney. The success of this project led to others in towns throughout the eastern parts of Australia – West Wyalong, Southern Riverina, and Northern NSW. Gradually the company expanded its expertise to include water supply pipelines, pump stations, treatment works and grain silos. Right from the start the company demonstrated a capacity for innovation by searching out and providing the most cost-effective solutions

The beginnings of trenchless technology

Very deep pipelines were a challenge to construct, requiring large spaces and considerable machinery to handle and stockpile spoil. It was also time consuming and had a considerable impact on the land surface above.

Beginning in 1956 in mid-western New South Wales, a new tunnelling method was trialled, improved and perfected by the company. It was called the ‘pot and drive’ method and involved boring vertical shafts along the line of the pipe and connecting them with an unshored tunnel at the bottom.

This marked the early beginnings of trenchless technology.

A new era

Harold’s son, Ron Weaver, was appointed as Managing Director and grew our operations across the entire east coast. He also expanded our range of services, adding gas and oil pipelines to the sewer and water supply pipeline business.

Our first joint venture

Ron Weaver saw an opportunity to improve the way ground dewatering services were carried out. He met with representatives from Stang Hydronics Inc. who were keen to form a partnership and start operations in Australia. He established a lasting and trusting relationship with John Stang Jr and an agreement was secured on a handshake.

This marked the creation of the John W Stang (Aust) Pty Ltd joint venture (later renamed Stang Australia) and the company’s expansion into dewatering services.

Building long-standing international relationships

Continuing the tradition of seeking ways to do things better and more efficiently, the company searched the world for advanced trench support techniques. In the 1970s we formed what would become a 30-year relationship with a German company, Emunds and Staudinger, who manufactured modular trench boxes.

This innovation revolutionised safe construction of deep trenches. Works were progressing faster and the workers on site were safer.

Later, the partnership with Emunds and Staudinger would evolve into an exclusivity agreement, with Vortec Industries (formerly Stang Australia) becoming the sole seller and lessor of trench boxes in Australia and New Zealand.

Stang Australia becomes Vortec Industries and 100% Australian-owned

General Constructions acquired 100% ownership of Stang Australia, and the company was renamed Vortec Industries. The newly named entity started expanding its range of products and services to complement its dewatering capabilities. Vortec Industries began renting specialist equipment, such as pumping and excavation support, to the building and construction industry across Australia.

The beginnings of trenchless technology and the third generation of Weaver leadership

Geoff Weaver, the third generation of the Weaver family to lead the business, took the reins in 1991. He led the company for 30 years and is now Chair of the Interflow Board.

Around this time, the company was investigating the emerging pipeline renewal market. Quotes were called for the replacement of a 300mm pipeline on the Central Coast. The pipeline was about 5 metres deep, in water charged ground beneath a busy road – a difficult project in anyone’s terms. Not for the first time, the company brainstormed to find a better way to provide the solution.

The company had become aware of an Adelaide-based company called Rib Loc who were developing technology to replace a pipeline without the need for excavating. After consultation with Rib Loc, an alternative solution was proposed to renew the pipeline using ‘trenchless technology’. The client accepted this alternative solution and a short while later our crews were on site with Rib Loc support installing their first ever Expanda® structural liner.

The success of this project and others that followed signalled the start of a decades-long relationship with Rib Loc Australia (now Sekisui Rib Loc Australia). In 1993, the partnership was formalised, and we became the exclusive provider of Rib Loc’s suite of innovative spiral-wound technologies in Australia and New Zealand – a partnership that remains to this day.

To carry out pipeline renewals, the Pipeline Rehabilitations business was formed.

The birth of Interflow

In 1996, the different entities – General Constructions, Vortec Industries, and Pipeline Rehabilitations – were brought together under a new name, Interflow.
The creation of the Interflow brand proved to be a seminal moment and corresponded with a significant push into the exciting new area of trenchless pipeline renewal.

Creating the Future of Water

In 2011, we acquired Infratec, marking our expansion in the water market. From this platform, we developed enhanced solutions to our customers’ problems in the potable water space.

The decade that followed was a period of rapid expansion. We gained new capabilities and technologies, providing our customers with a complete service offering across the 4 Waters: water, wastewater, stormwater and culverts.

A new chapter begins

2022 marked the beginning of a new era. As part of our evolution, Geoff’s son, Daniel Weaver, was appointed as Interflow’s Managing Director. Daniel will diligently lead the next phase of the Interflow growth journey.

We’re here today because we operate with honesty, reliability, competence and respect, with a drive to solve our customers’ problems.

Geoff Weaver
Former Managing Director

Milestone projects