MINNEAPOLIS — The Metrodome roof will deflate for the last time next month.

Mortenson Construction, the contractor building the new Minnesota Vikings stadium, said Friday it will cut the Metrodome’s power on Jan. 18. Company vice president John Wood said the first step after that is to deflate the Teflon and fiberglass roof.

The Metrodome’s facilities manager said he expects the deflation to only take about 30 minutes. The roof fabric will be cut into small pieces and possibly recycled.

Preliminary work has started around the Metrodome, where its replacement will be constructed. The Vikings plan two seasons at the University of Minnesota’s stadium.

Also Friday, the Minneapolis City Council gave its go-ahead for a $400 million business, retail, residential and parkland development around the new stadium.