He joined the National Association of Operative Plasterers (NAOP), and began working full-time for the union in Newport, Wales.
Otley died suddenly in 1922, and Telling was appointed as acting general secretary of the union, winning an election to the permanent post in September.
[3] In 1936, Telling visited the Soviet Union, but reported back that British building methods were superior.
Membership then began declining, and in March 1949, Telling reached 65, the set age for retirement from union offices.
The process to elect a replacement left him in office for a further year, but an operation near the end of 1949 led him to take several weeks off work.