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Rotorua Museum Roof Remediation

A Century of Leaks, Finally Laid to Rest.

Rotorua Museum Roof Remediation

Primary Contractor: Watt & Hughes
Waterproofing Contractor: Radford Roofing
Architect(s)/Consultant(s): DPA Architect

Development Manager: Rotorua Lake Council

Project Overview

Rotorua Museum Roof Remediation. Rotorua Museum, a Category 1 heritage building, had a long history of roof failure since its original construction in the early 1900s. In 2024-2025, the site underwent structural, seismic & waterproofing remediation with membrane detailing designed to eliminate recurring moisture ingress issues.

Challenges and Solutions
  • Rebuilding the Tudor-styled architecture roof to match heritage appearance.
  • Waterproofing irregular roof geometry, internal gutters, and public-access viewing deck.
  • New Zealand’s high UV exposure and minor seismic movement.
  • Providing a safe, trafficable finish for the viewing deck.
Key Component Products

 

ARDEX WPM 715 (WeldTec Exposed Membrane):

  • Primary membrane system across internal gutters and flat roof sections.
  • Selected for its flexibility, weldability, UV resistance, and ability to conform to complex detailing.

ARDEX WPM 170 (PU Membrane/Coating):

  • Applied over WPM 715 on the flat viewing deck to create an anti-slip textured finish.
  • Provided a durable, slip resistance surface suitable for public access without compromising waterproofing integrity
Outcome

The roof has been remediated to its original architectural intent while integrating modern performance standards. Internal gutters, flat roof areas and the trafficable viewing deck are now fully waterproofed with detailed membrane systems. The viewing deck features an ARDEX WPM 170 anti-slip coating applied over WPM 715, creating a safe, durable finish for public use. Overall, the entire system has been designed to withstand New Zealand’s harsh UV exposure, thermal ageing and seismic movement conditions.