Beginning next week, the project will be carried out by Glasgow-based company, SCS Group, which will provide 10 workers to scale the roof using walkways.
They will clean the entire outside of the roof, the panes above the station concourse and platforms, as well as the cathedral- like side windows, which are part of what is known as the Hielan'man's Umbrella above Argyle Street.
All the dirt and waste that has built up over the years, helped in part by the station's resident pigeons, will be scrubbed away to ensure it is sparkling clean in time for the Commonwealth Games in 2014.
Network Rail, the station's owner, says the works will not disrupt the operation of the station or train services.
David Simpson, the company's route managing director for Scotland, said: "Maintaining such a historic and imposing structure is of vital importance.
"This project will ensure the roof not only looks its best for the people who use Central every day, but also for those who will be visiting the city for the Commonwealth Games next year."
As Glasgow's main rail hub, Central Station is the busiest in Scotland, as well as the busiest in Britain outside London.
More than 35million people use the station each year.
And more than 1300 train services pass in and out of the station daily, going from anywhere in and around Glasgow to right down to Penzance, Cornwall.
It was opened on August 1, 1879 but had a series of extensions and remodelling before becoming the structure we know today.
The last of the extension works were completed in 1906, and can be distinguished from the original roof by their supporting girders.
The original ones are straight while those of the extension are curved.
The entire roof was renewed in 1998 as part of a £80m renovation of the station, which meant reglazing seven acres of glass – an area three times the size of Hampden Park.