A civil engineer has been appointed to investigate why Stadium Southland's roof collapsed under the weight of snow.
The velodrome was the only part of of the $10 million venue in Invercargill to have emerged unscathed.
Members of the charitable trust which owns the stadium met with Invercargill Mayor Tim Shadbolt and senior council officials on Monday afternoon to plan the scope of the investigation.
Civil engineer Graeme Cole has been appointed to find out what went so catastrophically wrong after snow piled up on the stadium's roof, causing it to collapse on Saturday morning.
Mr Shadbolt says he wants answers as soon as possible and expects Mr Cole's report within four weeks.
Demolition work will begin at the site on Tuesday and will be slowly undertaken to allow Mr Cole to forensically pick through the remains to determine what failed and why.
Meanwhile, plans are being made to ship a fully sprung wooden floor from Singapore which will be installed in the adjoining Velodrome facility to allow franchise netball and basketball games to resume.
The stadium is fully insured but could take as long as 18 months to rebuild. The original construction firm, Amalgamated Builders, will conduct the lengthy demolition process.
Truss design controversial, says mayor
The charitable trust has defended the stadium's construction after Mr Shadbolt said its truss design was controversial from the start and caused friction between the engineers and insurance underwriters.
Mr Shadbolt says he can recall people saying on numerous occasions that the roof could collapse in a major snowstorm.
He says the council relied on engineers' reports which were peer reviewed when it signed off on the stadium, but concedes the council's building codes may have to be looked at.
However, deputy mayor Neil Boniface on Monday questioned the position Mr Shadbolt has taken.
Mr Boniface says the peer review was undertaken by an engineer and some modifications were made which took the design beyond what the building code suggested was appropriate.
He questioned the tone of Mr Shadbolt's stance and suggested it has more to do with upcoming local body elections than with any major structural problem at Stadium Southland.
Acton Smith, who chairs the charitable trust, says there were never any shortcuts in its design, nor have insurers ever had any problems with it.
Mr Smith says some trusses had received extra strengthening - and those roof sections stayed intact and only came down later when the rest of the structure collapsed. Between 480 and 780 tonnes of snow were resting on the roof of the stadium, he says.
Mr Smith said the mayor's comments were made "without ever viewing the site".
Amalgamated Builders director Bruce Middleton says the design was done within the codes as they were understood at that time, but this was not something his company was involved with.
Stay off roofs, Civil Defence warns
Southland Civil Defence controller Neil Cruickshank warned business owners and residents to be careful when checking structures for snow damage.
"We don't want people up on their roofs moving snow, we'd rather nature takes its course."
At least 12 Southland schools have been closed on Monday due to the heavy snowfall.
Police are warning motorists in the region to be cautious as low temperatures could have caused ice to form on the roads.
Historic business suffer snow damage
The jobs of five fulltime workers at Wren's paint supply and decorating store on Yarrow St are in jeopardy after the shop's roof caved in under the heavy snow.
One of the owners, Dean Todd, says the business was established in the late 1800s. He says the damage is devastating and the building's future is unclear.
The roof of the New World Supermarket on Windsor St also partially collapsed.
