Project Overview

A decade after construction of the National Portrait Gallery, the basement waterproof membrane showed signs of failure, threatening the integrity of the building and valuable artworks. To remediate the issue, a new waterproof membrane was proposed to be installed over two stages. Following the successful delivery of Stage 1 Investigation Works, Complex Co was awarded the Stage 2 Major Works contract.

The second stage of works included replacement of the failed waterproof membrane at the podium and entrance, structural concrete remediation, replacement of window units and replacement of timber floor and subfloors throughout the galleries.

Installation of the replacement waterproofing membrane required demolition and reinstatement of all exterior architectural toppings. To mitigate against the risk of potential damage to the new membrane during reinstatement works, the team developed an innovative “permanent floating aluminium formwork” system, which simplified construction and features in defining the contrast of polished concrete toppings throughout the podium.

Other key features of the project included –complex artwork lifts, balustrade replacements, mobile display wall construction and architectural lighting.

Project Features

• Extensive detailed demolition of both interior and - exterior elements
• Strengthening of deflected architectural concrete slabs
• Detailed non-destructive engineering assessments
• Technical waterproofing and flood testing Technical crane lifts, including sculpture rigging
• Design and construct movable artwork display walls
• Reconstruction of detailed polished concrete
• Reconstruction of structural subfloor elements
• Installation of Tasmanian blue gum timber flooring
• Detailed marble stonemasonry
• Installation of oversized double-glazed units
• In house concrete maturity testing
• Stringent air quality monitoring
• Detailed landscaping works