A Roof Refurbishment with Minimal Disruption?
At the intersection of Khyber Pass and Symonds Street in Auckland City stands the Citta Apartments, comprising 105 residences, 90 carparks, and a ground floor commercial premises - all overdue for refurbishment. CS&R assumed the roles of Project Lead, Project Manager, and Engineer to Contract, implementing a strategic and resident-focused approach to address complex issues such as leaking roof penetrations, deteriorating butyl rubber gutter linings, and suboptimal energy efficiency.
Through effective project management, CS&R minimised occupant disruption by opting against a complete roof uplift and resident relocation. Instead, the team facilitated the overlay of the existing metal roof with a Viking WarmRoof system and Enviroclad membrane, ensuring watertightness and uninterrupted building operation. This environmentally responsible solution aligns with contemporary best practices in sustainable construction. By overlaying the current metal roof with new insulation and waterproofing systems rather than pursuing full replacement, material waste was significantly reduced.
With CS&R overseeing the design, engineering, tender and sequencing, the building was shrink wrapped and the 2,100m² roof waterproofing system was installed in stages:
- The team directed selective lifting of the existing metal roof to allow for structural assessment and fireproofing enhancements. Once verified as sound, the roof was reinstalled and converted into a warm roof vapour barrier with thorough air gap sealing. Internal gutters were reconstructed using new TPO-weldable scuppers to ensure reliable drainage.
- 75mm thick Polyiso insulation board was adhered to the metal roof substrate using a specialised polyurethane foam adhesive, followed by the application of a 1.52mm Enviroclad membrane and proprietary accessories—delivering full watertight integrity and improved thermal performance.
- In collaboration with the main contractor, CS&R, as Engineer to Contract, advised against a traditional walkway system that would compromise membrane integrity. Instead, they installed a proprietary heat-welded Enviroclad walkway, eliminating penetrations and ensuring robust, safe access for maintenance.
The team addressed challenges posed by variable parapet shapes and widths by directing the installation of Enviroclad membrane in smaller, strategically lapped sections, thereby preventing creasing and ensuring consistent waterproofing.
After years of planning and securing approvals, CS&R’s leadership was instrumental in coordinating all stakeholders. The project demanded careful planning, adaptability, and close collaboration with the main contractor, resulting in exemplary workmanship and stakeholder satisfaction. The successful outcome has led consultants, architects, and the Body Corporate to propose similar approaches for future projects.
Read the Roofing Association of New Zealand (RANZ) article here.
Read the EBOSS article here.