 From 1941 to 1945, Joensen was the editor of the Faroese-language newspaper "Búgvin" (Ready).In 1948, Joensen was one of the founders of the Faroese Republican Party () together with Erlendur Patursson, Jákup í Jákupsstovu, and Hanus við Høgadalsá, and from 1958 to 1970 Joensen was a member of the Faroese Parliament.Joensen received the Tórshavn council children's book prize for his works "Kálvamuan" (The Young Calf), "Lítli Sjúrður" (Little Sigurd), and "Lambamæið" (The Little Lamb) in 1977, and the Faroese Literature Prize for "Eg stoyti heitt" in 1987.