Allco Projects - Harewood Underpass

Harewood Underpass

Project Requirements

The brief was durability for the life of the structure

Industry Sector



A requirement to be leak free to maintain the integrity of both the profiled panel façades and the Architectural Coating.

Project Details

Project Name: Harewood Underpass

Applicator: Absolute Waterproofing

Products Used: Volclay product range

Completed: June 2016

The Project 

Project Overview: 

The Harewood Underpass is a pivotal infrastructure development located at the intersection of Russley and Harewood Roads in Christchurch. This 80-meter enclosed section facilitates pedestrian and cyclist movement and enhances safety en route to the expanding Christchurch International Airport precinct. 


The primary requirement for the underpass was to achieve robust, long-lasting waterproofing to preserve the integrity of its profiled panel façades and architectural coatings. Ensuring a watertight environment was crucial to maintain the structural integrity under varying environmental conditions. 

Solutions Implemented: 

To meet these challenges, Allco’s Volclay tanking range was selected for its superior waterproofing capabilities and resilience. The project utilized: 

Voltex: Applied to the underpass slab, ensuring a durable and effective moisture barrier.Swelltite and Aquadrain: Used on the walls and roof, providing added layers of protection. Swelltite’s high-swelling, self-sealing sodium bentonite offers both passive and active water ingress barriers, while Aquadrain assists in collecting and redirecting water away from the structure to designated drainage outlets. 

Execution and Results: 

The installation of these waterproofing systems was expertly carried out by Absolute Waterproofing Solutions, an Allco-approved applicator. Their meticulous application not only met but exceeded project specifications, resulting in a robust, watertight underpass that promises longevity and durability.