The replacement of the Metrodome roof began on Friday after the roof was damaged by a December snowstorm.
Workers began with three diamond-shaped panels that will be stretched and clamped into place. The process takes about a day for each panel.
The Metropolitan Sports Facilities Commission voted on Feb. 10 to replace the entire Teflon roof, as opposed to just the damaged panels, on advice from engineers. The goal is for the roof to be finished by Aug. 1, and work will continue six days a week until it is completed.
The damaged roof forced the Vikings to play two home games away from the Metrodome in 2010. They played the Giants in Ford Field in Detroit and the Bears in TCF Bank Stadium on the campus of the University of Minnesota.