The retractable roof on top of the Falcons' new stadium has been one of the biggest construction nightmares in the history of professional sports, but it appears that nightmare is now over. 

The parent company of the Falcons, the AMB Group, has announced that the roof is finally functional after being hit with multiple delays. To prove that the roof actually works, the AMB Group invited media members to watch it open and close on July 25. 

According to the Atlanta Journal-Constitution, the roof was able to open in eight minutes and 10 seconds. After that, it was able to close in just seven minutes. 

As you may or may not have noticed, the one-of-a-kind retractable roof looks similar to a camera aperture when it opens and closes, which is by design. Construction workers had a difficult time putting the roof together because nothing like it had ever been built before. 

Mike Egan, a senior vice president with the AMB Group, said it was a "relief" to finally see the roof functioning. 

"It took as long as it did because this is a busy building and we had to work around events," Egan said, via AJC.com. "It's a relief, but we really never had any doubt we would get to this point. It's more just a feeling of exhilaration to see it working the way it is supposed to."

The ongoing issue with the functionality of the roof was a big reason why the opening of Mercedez-Benz Stadium was delayed a total of four times. First, it was supposed to open in March 2017, which then got pushed back to June, before being pushed back to July. The stadium opening eventually happened on Aug. 26, 2017, when the Falcons played host to a preseason game against the Cardinals.

During the 2017 season, the roof was open only one time, and that was for the Falcons' Week 1 game against the Packers. After that, the roof was left in a closed position, but even then, it still caused problems. In October, the roof leaked during a high school marching band competition at the stadium, and then it leaked again just before the College Football Playoff National Title game in January.

Despite all that, Egan said his group was never worried that anything might be broken. 

"It was never a question of the roof being broken or unsafe," Egan said. "It was literally just a question of needing to get the balance (of the roof) right so the propulsion system would achieve its desired life."

The retractable roof was built with eight unique roof petals, which each measure in at 200-feet and weigh 500 tons, according to the AJC. 

The Falcons are hoping to have the roof opened for most games, even if there's a chance of rain. According to Egan, rain won't be a problem because the stadium is designed to get wet.  

"That allows us to open the roof if there is a 25-percent chance of precipitation because we have drainage and because everything in this stadium is designed to get wet," Egan said. "We're going to open it as much as we can. Fan comfort will be the No. 1 priority."

That's probably exactly what the NFL wants to hear and that's because the league wants the roof of the stadium open for the Super Bowl in February. Super Bowl LIII, which will be televised by CBS, will be played at Mercedes-Benz Stadium on Feb. 3, 2019.