LYNN – Even Lynn’s seat of government with its stone ramparts is not immune to winter’s onslaught, with city officials closing the City Council chamber Tuesday after melted snow soaked ceiling plaster.The leak prompted councilors to take what city Inspectional Services Director Michael Donovan called the “very unusual” step of moving their Tuesday meeting to Veterans Memorial Auditorium.Donovan said the leak will take about a week to repair and cost taxpayers about $5,500. Some of the expense is associated with the small but measurable amount of asbestos contained in the ceiling plaster.”It’s also a little bit expensive because they will be working 30 feet in the air,” Donovan said.After a city employee spotted water dripping from the chamber ceiling on Tuesday, a closer inspection detected sodden plaster. Donovan ordered the high-ceilinged room with its audience seating and work area for 11 councilors closed and called in a hygienics firm to test air in the chamber for any sign of asbestos.”It’s standard operating procedure. We shut down the room to not expose anyone to potential asbestos,” he said.Asbestos enhances the ceiling’s acoustic qualities, Donovan said, even though the ceiling contains a relatively small amount of the material. Donovan said the leak is confined to a roughly 20-square-foot ceiling area and workers set up scaffolding underneath the damaged area on Tuesday afternoon.He said the leak occurred in a heating and ventilation duct mounted above the ceiling, and snow got sucked into the duct, melted and leaked through a crack or weakened section of the duct, soaking the plaster.Lowell-based TRC is conducting air testing, Donovan said, and contractor New England Surface Management is drying the ceiling before patching and painting it.City Council President Daniel Cahill took the unanticipated change of meeting location in stride.”Like many homes and businesses, the amount of snowfall has caused some leaking. Under an abundance of caution, we decided to move the meeting to ensure public safety,” he said.