Office Tower Roof & Plantroom Spotlight
There’s plenty to see as construction on Te Kete progresses — façade installation on the office tower, structural steel and mass timber taking shape on the new library, and concrete trucks and pumps moving regularly through site.
But some of the most important work underway is happening well above street level and largely out of sight.
On the roof of the office tower, two of our local subcontractors have been busy delivering critical elements that will help keep the building watertight and support the services it needs to operate:
Turfrey, installing the roofing system in partnership with RoofLogic; and
Patton Engineering, completing the structural steel installation for the rooftop plantroom.
Both are familiar names on the Te Kete project. We previously featured Turfrey in our December 2025 Project Update, while Patton Engineering featured in our September 2025 Project Update.
This spotlight takes you onto the roof of the office tower to look at the work that’s been happening out of view.
Office Tower Roof
The office tower roof is a specialist warm-roof system. Rather than being a single layer, the roofing build-up comprises several different materials, each playing an important part in keeping the building insulated, protected and watertight.
The roofing build-up includes:
50mm fillets installed within the profile of the existing metal tray roof to create a level surface. This allows the existing roof to remain in place and become part of the new roofing build-up.
A vapour control layer (VCL) is installed over the prepared existing roof, helping manage moisture within the roofing system.
Two layers of high-grade insulation are installed - 60mm stonewool insulation and 80mm foil-faced PIR insulation. The stonewool insulation is an extremely dense insulation material, with a similar density to a brick.
An ILD electronic leak-detection layer is incorporated before the high-density RoofLogic DriGard XT roof boards. This allows the completed roof to be electronically tested to help identify the location of any leaks.
The complete roofing build-up is securely fixed back to the tower’s structure using 225mm HD fasteners and pressure plates.
Spray adhesive is then applied before the final Fibretite waterproof membrane is installed. The joins and detailed areas of the membrane are heat-welded together to create the finished waterproofing layer.
Some key numbers:
7.5–8 tonnes of specialist roofing materials have been supplied to date, with further materials still to come.
Approx. 744 individual insulation and roof boards have been installed – comprising 478 Stonewool boards, 134 PIR insulation boards and 132 high-density RoofLogic roof boards).
Laid end-to-end, the PIR fillets would stretch approximately 1.6 kilometres - around 16 rugby fields in length.
Approx. 9 rolls of slate-grey Fibretite membrane have been supplied to date.
See the roofing build-up in action
Check out the photos below for a closer look at the different layers that make up the office tower roofing system.
Turfrey Roofing Team
Roofing Works – looking ahead
Turfrey will shortly begin roofing and cladding works to the office tower plantroom. Their work on Te Kete will then continue, with Turfrey also installing the roofing systems for the new library and council chambers.
Office Tower Plantroom
At 70m2, the new office tower plantroom is approx. 40% larger than the original.
The plantroom is essentially the engine room of the office tower. It houses the mechanical equipment that runs the tower’s ventilation, heating and cooling systems.
The new plantroom will contain:
two chiller units;
one large air handling unit;
two buffer tanks connected to the air conditioning system;
two pumps;
mechanical ducting & piping;
drainage piping; and
an electrical distribution board.
Patton Engineering installed the structural steel that forms the plantroom structure - a total of 228 steel assemblies weighing approx 7.8 tonnes. The steel was craned onto the roof by Lattey Group.
MCLStead then installed the plywood and is currently installing Slopeshield, a peel and stick membrane that provides an additional weathertight barrier.
Once this is complete, Turfrey will begin installing the plantroom roofing and cladding. This will involve approx. 1,000 linear metres of Roofing Industries Spanlok concealed-fix metal roofing and cladding across the plantroom roof and external walls.
Once the Spanlok roofing and cladding is complete, the scaffolding surrounding the plantroom can be removed. This will allow Turfrey to return to the remaining areas of the main office tower roof and complete the RoofLogic warm-roof and Fibretite membrane system.
Completing the work in stages allows each of the different roofing systems and associated works to be installed in the right sequence as the wider office tower refurbishment progresses.
Take a closer look at the plantroom
Check out the photos, structural drawings and 3D images below to see how the plantroom is taking shape — and what will eventually sit inside it.
