Firefighting gear at the NZICC site this week. Photo / Jason Oxenham
A major Auckland building site was shut down with illegal fire safety systems, a building boss says but the council says only one offender was involved.
"We're shut down for about two days now," said the chief whose company is working on a multi-million dollar high-rise building site where fittingsor equipment were found not to meet building regulations.
"We had to send all the workers home but we'll get the systems in and comply and be right back again," he said.
But Jeff Fahrenson, Auckland Council's manager field surveying, said: "Yesterday we issued a notice to fix to a building company at one site who had been repeatedly warned and instructed over the last month to install their hydrant riser. This was the result of a known non-compliance from well before the SkyCity fire and would have been issued regardless of this fire emergency."
No other jobs were stopped, Fahrenson stressed, and the council had been actively checking and auditing risers on multi-storey building sites for some time.
The building boss said metal water pipes, or risers, must be installed and charged or fully pressurised to within 9m of the top of any construction site "and when the inspectors arrived yesterday morning at one of our sites, they had a list of other sites they were visiting in the area".
"This is a direct result of the convention centre fire because the council are at our sites maybe twice a week but nothing like this has ever happened before," he said.
Although those risers would be inspected and signed off eventually, he said it was too much of a coincidence to have the unexpected visit on the second day of the NZICC fire.
A Fletcher Building spokesperson said in response to inquiries about NZICC hydrant systems and whether the risers were charged: "We can't comment on what other construction companies are doing but I can confirm that our NZICC project was and is compliant in this regard."
The builder said a fireman fighting that blaze told him the risers were only charged to level two of the $703m seven-level site.
Another building chief also confirmed the sudden fire safety inspections and said that the regulation or standard NZS4510 required all buildings under construction over 9m to have a charged riser installed within 9m of the highest point of that building.
That enabled firefighters to reach those upper levels with pressurised systems, he said.
"This hasn't been happening and as a result, the council are putting stop-work notices on some projects in town," he said.
"This will become a challenge when a developer hasn't got a new water brigade water supply provided to the site by the time construction has reached that height. Unfortunately, it's taken a fire like this one at the convention centre to awaken everyone."
Where building construction included installation of a permanent building hydrant system, fire safety risers had to be installed and brought into commission progressively as building work proceeds, he said.
If the consent does not require a permanent hydrant, then there would be no requirement for any riser system during construction.
"In multi-storeyed buildings, the system has to be functional with a building hydrant outlet on every floor up to a level not lower than 9m below the highest floor slab," he said.
During construction, a permanent water supply might not always be available. Then, a temporary connection would be acceptable via the site water supply to ensure every section of the hydrant system pipework which has to be kept charged with water at a positive pressure of at least 15kPa.
Charged risers supply no fire-fighting water.
"It's only an inlet that the fire service pump their own water into with a reticulated pipework system and outlets throughout the building where they can then draw water and run their hoses from. No additional water supply is ever required apart from the 15mm charging line," he said.
The pressurised supply has to be through a pipe of not less than 15mm diameter and be capable of maintaining a flow of 25 litres/minute, he said.
A pressure gauge must be installed at the inlet so when the fire service arrives they know there is no hydrant valves open on any floors. This is all the charging line ever does, he said.
Taller buildings where the highest outlet was greater than 40m from the ground, required a booster pump which may be part of the system design, he said.
Those systems were commissioned once the construction height reached 40m because the fire trucks cannot pump their own water that high.