Allco Projects - Pito-One to Melling Underpasses

Pito-One to Melling Underpasses

Project Requirements

A robust and resilient solution for the underpasses of the Pito-One (Petone) to Melling section of Te Ara Tupua.

Industry Sector



Allco’s complete tanking range was the ideal solution for this vast project. 

Project Details

Project Name: Pito-One to Melling Underpasses

Builder: Fulton Hogan Civil South

Architect: Isthmus Group

Products Used: Voltex and Swelltite.

Completed: October 2023

The Project 

Te Ara Tupua is a walking and cycling link to improve transport options between Wellington and Lower Hutt, providing an efficient and attractive choice for commuters. It will deliver a safe, connected and resilient route, enabling more people to walk or bike, and connect with local paths in both Wellington and the Hutt Valley.  


The 3.5 kilometre walking and cycling route includes 2 underpasses below the road to ensure safety for commuters while not interrupting the train line. The key requirements to waterproof these underpasses are durability for the life of the structure with a need to be leak free to maintain the integrity for years to come.  

The size and scope of the project meant that strict deadlines were in place and all professions needed to be able to work together to ensure those deadlines were met. The key train line was shut down while works were completed which meant a very tight schedule of works for creating the underpasses. 


Allco’s Volclay range was the ideal tanking solution for this project as its durability and effectiveness are second to none. The swellable Voltex actively self-heals and self-seals small concrete cracks caused by ground settlement, concrete shrinkage or seismic action; problems over which there is normally no control. 

Keeping the programme on schedule was a credit to all involved, especially the teamwork and calm approach exhibited by everyone. The challenges suited the Volclay range due to its ability to be applied while other trades were working and when necessary to stop and start application quickly. 

“Absolute waterproofing application and team work on site ensured a professional and quick installation. Their combined attention to detail and accuracy of application was some of the best I have personally seen in 20 years.” Alex Valentine, Managing Director 

Allco was proud to be a part of this project to revolutionise the greater Wellington area and help ensure safe and environmentally friendly routes for commuters and weekend wanderers alike.