Mr Pederson started up the big machine and manoevered it to the building's side, extending the arm all the way up to the roof where the man was attempting to shield himself from the heat with a scrap piece of chipboard.
"I just thought he was going down. Otherwise, he would burn up and the crane was the only tool we just had at hand," he said, in an interview translated from Danish.
The tradesman on the roof was able to grab hold of two iron chains handing from the boom, holding on for dear life and swinging away from the flames.
Tense colleagues looked on as he emerged from the clouds of thick black smoke and was slowly lowered to the ground, and a number can be seen in the video running to his aid.
The other man working on the roof managed to jump down to a lower floor and escape.
Both were taken to hospital with burns to their faces and hands.