MINNEAPOLIS (Reuters) - The Metrodome stadium roof that collapsed in a snowstorm last December will be completely replaced, the commission that oversees the facility decided on Thursday.

The estimated $18.3 million replacement of the roof will be fast-tracked with plans for substantial completion by August 1 in time for National Football League preseason game of the Minnesota Vikings, under plans approved by the Metropolitan Sports Facilities Commission.

The Metrodome roof is held aloft by air pressure and collapsed in a snow storm on December 12 when snow and ice could not be removed quickly enough from the structure.

The roof deteriorated more in the two months of severe winter that followed and engineers could not recommend a partial replacement, according to reports released on Thursday.

No one was injured in the collapse. Insurance money is expected to cover the cost of the replacement.

The failure of the roof forced the Vikings to play one of its eight regular season home games in Detroit and a second at the University of Minnesota's outdoor stadium at the end of last season. The team failed to make the playoffs.

The Vikings are in the last season of their Metrodome lease and team owners have lobbied for several years for a replacement to the Metrodome, which opened in 1982. They have been looking at a number of sites for a potential replacement, including the current site of the stadium.

An annual report on NFL team values by Forbes magazine placed the Vikings near the bottom of the list.

The dome is overseen by the Metropolitan Sports Facilities Commission. Commissioners are expected to decide on contractors at a meeting on February 25.

(Reporting by David Bailey; Editing by Greg McCune)