Jamtfall was born in Trondheim[1] and started to play football for the local clubs National and Astor before he joined Rosenborg at the age of 15.
[4] Jamtfall made his debut for the senior team in the first round of the 2005 Norwegian Cup against Orkla[5] and joined Rosenborg's first-team squad after the 2005 season.
[2] In January 2006, FK Bodø/Glimt wanted to get Jamtfall on a season-long loan deal as a replacement for Trond Olsen on the left wing.
[7] One week later Jamtfall came on as a substitute for Øyvind Storflor after 68 minutes[8] and scored his first league-goal when Lillestrøm was beaten 3–1 in Knut Tørum's first match as head coach of Rosenborg.
[13] After playing 16 matches and scoring one goal for Ranheim in the First Division,[1] Rosenborg decided to call Jamtfall back from loan, nine hours before the transfer window closed on 31 August 2010.
He stated that he lacked motivation because of all the injuries, and said that "I've won the league and played in Europe with Rosenborg, now it's time to focus on life outside football".