Before he was elected County Mayor in 2003 he also worked as a project director for Extend. He was reelected in the 2007, 2011 and 2015 elections. When Nord and Sør-Trøndelag merged in 2018, he continued as county mayor for the new county before winning another term in the 2019 local elections.[4]
In 2022, Sandvik announced that he would not seek re-election in the 2023 local elections. The Trøndelag Labour Party chose Per Olav Skurdal Hopsø as their candidate for county mayor.[5]
After the 2023 local elections, Labour's coalition partner the Centre Party joined the conservative block in order to get the county mayor position, thereby putting an end to Sandvik's term.[6] He was succeeded by Tomas Iver Hallem on 18 October 2023.[7]
Personal life
Sandvik grew up in the borough of Kolstad in Trondheim.