Work has begun with scaffolding assembled and plans for the ventilation system to help achieve dry building weather-tightness.
"The library is well used with over 1000 visitors per week, [so] the work has been planned to minimise public inconvenience as much as possible," council head of libraries and visitor information Debbie Duncan said.
The original Carnegie Library was built in 1914, and extended in 1989 and 1993.
This resulted in a roof with numerous different designs, that went on to suffer water leaks in many areas for over 20 years.
This included replacement of an entire roof section within the last three years.
"Unfortunately, the remaining areas of the roof can no longer be repaired and require full replacement to make the building watertight," Mrs Duncan said.
"It is anticipated the entire project will take about six weeks, but this will be subject to weather or any issues [rotten timbers, etc] that may arise during the work."
The library carpark and rear walkway is closed and at a later stage in the project the main entrance will be temporarily closed, with entry via the Stewart St side door.
In late June the library is expected to be closed for a week to enable further work to be carried out in essential areas.
The council has engaged local contractors for both the roof replacement and installation of a new ventilation system.
During last week’s council committee meetings, council chief executive Steve Hill reiterated a $500,000 figure circulating for the repairs on social media was a budget, rather than the final cost.
Mr Hill said the expected cost was about $160,000, leaving the surplus remaining in the budget for future projects.
