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Alumnium cladding with a combustible core was blamed for the Grenfell tower disaster.

Stadiums, university and hospital buildings in Auckland have been found with cladding similar to that in London's fatal Grenfell tower fire.

The owners of the AUT Millenium Stadium, Waitakere Stadium, Auckland University's Owen G Glenn Building and the corporate offices of Spark and PWC have all been advised by Auckland Council to inform their insurers and seek engineering advice. 

The buildings are among 25 identified as having the aluminium composite panels (ACP) with a polyethylene core linked to the Grenfell tower disaster.

DILEEPA FONSEKA/STUFF

Penny Pirrit, left, and Ian McCormick, right, from Auckland Council spoke to media about the ACP cladding investigation.

Auckland Council's general manager of building consents Ian McCormick stressed that the buildings were safe because of a range of other measures in place including sprinkler systems and fire alarms. 

READ MORE:
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* After London tower fire, Government checks NZ buildings
* London fire causes building industry concerns about cladding

At a press conference on Tuesday afternoon McCormick said 300 buildings had been assessed so far but the investigation was continuing.

"After this media release we're expecting we are going to get some further assistance from the public."

McCormick believed Auckland Council had identified most of the buildings in Auckland with ACP that were over 25m tall and the majority of those between 10m and 25m in height.

A spokeswoman for Auckland Council said over 5,000 residential apartments and hundreds of commercial offices had some form of ACP cladding, but that included those with fire rated panels and a modified "less combustible" core. 

Some buildings identified with aluminium composite panels with fire-rated panels included the NZME building on Graham Street and the Crowne Plaza hotel.

ACPs with a fire-rated panels still satisfied the requirements of the building code, McCormick said.

Eight buildings at Auckland Hospital were identified as having aluminium composite panels, some with a polyethylene core and others with fire rated panels. 

McCormick said ACP "does not make the building dangerous or unsafe".

The notation that ACP had been used on a building would be placed on property records on individual apartments held by the council but would not appear on LIM reports, according to a statement on Auckland Council's website.

"We are currently working out how this will be documented."

McCormick acknowledged that ACP panels had been removed from several buildings in the United Kingdom after the Grenfell fire but said in those cases many of the buildings were owned by local or central government.

Seventy two people died after the fire in the London apartment block, Grenfell tower, last year.

Decorative aluminium panels with a combustible polyethylene core were identified as a major factor in the ferocity of the blaze. 

Soon after the Grenfell fire, then-Building and Construction Minister Nick Smith highlighted an amendment to the building code made in January last year where flammable aluminium cladding had been banned from multi-storey buildings. 

McCormick said ACP with a combustible polyethylene core could still be approved for use on New Zealand buildings but there would be "a lot of questions to be asked" at the consent stage. 

Smith said at the time he had instructed Ministry of Business, Innovation and Employment officials to contact councils to check if any such buildings had been constructed before the ban.

Last year Auckland Council said an investigation had been in place prior to the Grenfell blaze that had assessed about 215 buildings in the city, and found 13 buildings that were clad in polyethylene-filled (PE) aluminium panels similar to those on Grenfell tower.

ACPs were often applied to the outside of buildings as a design feature because the aluminium sheets could be easily painted over. 

Speaking at a press conference about the investigation last year, McCormick said the public should think of the panels as an "aluminium sandwich", with a composite material sandwiched between two sheets of aluminium. 

A guide released by MBIE in May 2016 noted that in a fire the aluminium sheets would heat up and "conduct quickly" to the core composite material. 

If the core was polyethylene, for example, it would melt quickly, bending the aluminium back and exposing the polyethylene to flames, a problem because polyethylene "combusts vigorously".

"ACP claddings with a 100 per cent PE (polyethylene) core have contributed to rapid and extensive vertical fire spread."

MBIE advice noted that aluminium composite panels (ACP) with a core of polyethylene (PE) had been a factor in large apartment fires in both Melbourne and Dubai.

As part of the building code, the external cladding of buildings must be designed so that a fire does not spread more than 3.5m vertically. 

Notable buildings found with ACP:

* Auckland Hospital (up to eight buildings), Grafton

* The Owen G Glenn Building, University of Auckland

* TVNZ Building, Auckland CBD

* PwC Building, Auckland CBD

* Waitakere Stadium, Henderson

* The Spencer on Byron, Takapuna

* Spark Centre, Auckland CBD

* AUT Millenium Stadium, North Shore.

* Viaduct Point Apartments, Auckland CBD
 

 - Stuff