In the 1940s he was a board member of Potetmelfabrikantenes Salgskontor (1940–1945), Gartnerhallen (1941–1945), Felleskjøpet (1946–1949) and NLVF (1949–1955). During the occupation of Norway by Nazi Germany Sandberg was a member of Hjemmefrontens Ledelse, and he was a candidate for Gerhardsen's First Cabinet after the war. He was drafted into and the board of . In the 1950s he became chair of Hedmark Agrarian Association (1951–1953) and the Norwegian Agrarian Association (1951–1955). He also served one last term as councilman in Furnes, from 1955 to 1959. He was elected to the Parliament of Norway from Hedmark in 1957, and was re-elected in 1961. After declining re-nomination and leaving Parliament, he chaired a committee from 1966 to 1967 founded by the Ministry of Finance to evaluate the tax and duty system of Norway.