St. Patrick’s Cathedral will soon undergo an unprecedented $175 million renovation — an overhaul so massive, it took five years just to plan.
Scaffolding covered in protective black netting will surround the inside and outside of the 133-year-old Fifth Avenue landmark by the end of April — and will remain there for at least the next two years.
In May, work crews numbering 50 to 100 people will begin replacing the crumbling marble blocks, refitting century-old stained-glass windows and refinishing scuffed pews.
“We have a doctor’s approach: First, do no harm,” said Derek Trelstad, lead structural engineer on the project.
A team of consultants, led by conservators with experience renovating historic buildings, cataloged every deficiency marring the cathedral.
“The goal at the end of the day and tens of millions of dollars is to have it not look a whole lot different. The discerning eye should notice it is cleaner, but it should look, as much as it can, like it did in 1879,” said Trelstad, of the firm Robert Silman Associates.
Timothy Cardinal Dolan is expected to announce the details of the historic project tomorrow.
Construction equipment will take up a lane of traffic on both East 50th and East 51st streets. Work will be done from around 7 a.m. to 3:30 p.m. each day. During that time, the restoration will stop only for daily Masses.
Inside, workers will replaster the vaunted 118-foot ceiling.
The bronze Madonna adorning the roof of the Lady Chapel will be scrubbed as well.
The stained-glass windows of the Lady Chapel, located in the rear, also will be restored, as will 34 French stained-glass windows from the 1870s.