One of the better shotblockers of his era, Allum played hockey for more than twenty years. He started out with the Elmwood Maple Leafs of the Manitoba Midget League, moved up to East Kildonan for juvenile, and finally Winnipeg Rangers and Canada Packers in junior and senior city hockey.
His first pro team was the New York Rovers, and although Chicago bought his rights he played just one NHL game for the Hawks in 1939-40. The next year, he played one game for the Rangers, and that represented the sum total of his NHL experience.
By 1943 he was in the Canadian Army for two years during which time he continued to play hockey with Winnipeg and Cornwallis. After returning to civilian life he played mostly in the AHL in the States and senior hockey with the Owen Sound Mercurys where he was both a skater and a coach, winning the Allan Cup in 1951. He retired from hockey in 1953.