At least 12 storm-loosened Vikings stadium panels being re-attached

The metal cladding on the outside of the new Vikings stadium is getting a going-over after a storm earlier this month loosened some of the zinc exterior panels.

The foot-tall panels are 6- to 12-feet long, and interlock on the side of the building. They're made in France, and there are hundreds of them on the outside of the building.

The panels led the building its distinct dark look. They also provide a "rain screen" to help shed some water outside of the building's waterproof exterior.

More than a dozen of them came loose in a wind storm July 5.

"Certain parts of the building are experiencing sort of unusually high wind pressures," said Mortenson Construction's vice president, John Wood, in a report to the Minnesota Sports Facilities Authority Friday. "That's created not only by the geometry of the building itself, but just the way that the wind moves and is impacted by the other surrounding buildings in downtown Minneapolis."

He said construction workers noticed the wind phenomenon as they were putting up some of the internal steel work.

Mortenson and the MSFA have brought in consultants to look at the matter and talked with the architects.

"Over the course of the last two weeks ... we've added additional fasteners to certain of the metal panels that are in areas that are exposed to these particularly high wind pressures," Wood said.

The work is about half finished, and won't be done before the building opens to the public next week. But Wood doesn't anticipate it will pose a hazard or obstacle for the opening.

"I think it would be prudent for the MSFA and ourselves to continue to monitor the behavior of the building as it is put into use and as it is exposed to our great Minnesota weather," Wood said in an interview.

He said warranties on materials and the systems will mean the cost of remediation shouldn't fall to the MSFA or taxpayers if more repairs are needed in the near future.