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Just because the doors are open at U.S. Bank Stadium doesn't mean the work is done on the $1.1 billion building.

Workers continue to scale the heights of the soaring glass and steel structure, removing and reinstalling visible chunks of the exterior zinc panels. Relax, it's all normal and under warranty for two years, said M.A. Mortenson Construction executive John Wood on Friday.

The work addresses current and potential problems. Much of the remediation involves recent visible flapping of zinc panels after heavy winds. The panels initially held in place along the bottom are now being fastened along the top as well. Wood expects that work to last up to another three weeks. The panels were not at risk of coming off the building, he has said.

That might not be the end of the work. "Is it possible six months from now we might have to go in? Sure. Every building has some ongoing maintenance, and this building will be no different," he said.

Just like the new construction of any building, the stadium will be tested through an entire year of weather cycles, Wood said.

The building's had a couple problems already, one more significant than the other. In February, Mortenson announced a problem with the moisture barrier on a parapet. The water had not penetrated the building, but Wood said the problem required replacement of the barrier with a new product. Mortenson covered the estimated $4 million in repairs.

After storms earlier this summer, about two dozen zinc panels were visibly loose. While tightening those panels, crews also are taking extra time to check moisture barriers underneath, especially on the most severely sloped portions of the building on the northwestern side, Wood said.

Almost daily, skeptical observers post photos of the ongoing stadium work on social media and question the building's durability. The doubts are likely fueled by the building's predecessor. In the early days, the Metrodome's roof fabric tore multiple times. While the building was a workhorse, it never became a comfortable or sentimental home for the teams or fans. When the roof collapsed under a heavy snow in 2010, the building's reputation as a subpar facility was permanently set.

Wood made his comments about the ongoing work at U.S. Bank Stadium after a regularly scheduled meeting of the Minnesota Sports Facilities Authority. The meeting included a budget update during which executive director Ted Mondale said there will be $2 million remaining in a contingency fund after all work is done.

That means the project was completed on time and under budget, he said.

Rochelle Olson • 612-673-1747

Twitter: @rochelleolson