He worked for the Sunshine Harvester Company, before serving in World War I in France.
On his return he qualified as a chartered accountant and worked for the Victorian Crown Law Department.
On 15 January 1927, he married schoolteacher Thelma Camille La Mascotte Kirkham, with whom he had one daughter.
Tyack served during World War II as an amenities officer in Palestine and New Guinea, and was awarded the MBE in 1945.
He was briefly a Hawthorn City councillor again in 1954, but he then became a manager of Sir Arthur Warner's Universal Guarantee Company in Sydney, a position he held until 1963.