Podium Terrace Roof System

TVNZ Building Stage 1 & 2

ArchitectWarren & Mahoney
Facade EngineersMott MacDonald
ContractorFletcher Interiors
Specification2 X 10mm of Mastic Asphalt to multiple roofs, decks and podiums


The Existing roof and deck areas of the TVNZ Building were covered in Bytenol and a fibreglass coating overlay which had been installed years later to rectify historical leaks. The remedy had not worked. The existing roof had lots of plant equipment pipe penetrations plinths, curved walls and unusual details.  Also the roof and decks were designed many years ago to a 1-100 fall.

This left the Architects Warren and Mahoney the facade engineers Mott Macdonald and the client with a difficult choice of which product to select for the roof.

Which product is monolithic therefore could be shape around tricky details. It had to be seamless so as not impair water flow due to limited fall. It had to have along service use and be a tried and tested solution. Mastic asphalt was the answer.


To remove the existing membrane and replace with Pacoflex Mastic Asphalt. The roof was to be laid in 2 X10 mm of Pacoflex mastic asphalt with the addition of a reflective protective coating. The deck areas were to have a specification of 1 x10mm roofing layer topped with a 15mm roofing layer with the addition of 10% 3mm aggregate to help strengthen up the trafficable deck areas. All deck areas were then covered in deck jacks and pavers.  During the removal of the existing membrane great care had to be taken to avoid any leaks during this process as the building inside was being fitted out at the same time as the roof and deck installation. 

Asphaltech and their qualified tradesmen were intrusted to carry out the supply and installation of the mastic asphalt roof and deck membranes. Consultation on design and detailing was performed with the head architects throughout the project. 

"George Griffiths personally supervises his small team, who all work to highly professional standards ensuring that the exacting detailing required by the Museum's heritage architects is always met or exceeded. "
JOHN GLEN, Auckland Museum Facilities Manager // AUCKLAND WAR MEMORIAL MUSEUM
"Mastic asphalt has a long life span of 60 years (source RICS). Fully recyclable, it has a low impact on the environment. Benefits of mastic asphalt are its durable, waterproof, voidless and self compacting."
Pure Asphalt Company Limited – UK