From next Monday, construction is set to ramp up as gas, water and sewerage lines are being laid from the bottom of Kenyon Street.
The work, which will lead to traffic diversions and closures, will last for the next 12 months as the contractors make their way up through the North Tipp town.
The carpark at the Railway station will be free of charge for the duration of the works to ease congestion.
Construction Manager with Gas Networks Ireland Brendan McDermott says it's impossible to carry out a project of this size without disruption.
Business representatives in Nenagh say they're concerned Phase three of the gas project will lead to job losses.
