BANGOR, Maine — Bangor Public Library’s three-year, $9-plus-million renovation is finally approaching its conclusion, and library officials plan to show it off this week.

The library will host an open house from 3 to 7 p.m. Wednesday. Library staff will lead tours, snacks will be doled out, and the RetroRockerz will perform at 7 p.m. in the library’s new atrium.

“It’s pretty amazing,” Library Director Barbara McDade said during a preview tour Tuesday. “The staff and community members have put up with a lot while this was being renovated.”

“They soldiered on through the noise and dust and moving, and I’m very proud of them,” she added.

The renovation effort started back in 2013, after the library’s century-old copper roof sprung a series of leaks. The leaks caused a portion of a ceiling to collapse and sent water flooding down the library’s main staircase after a particularly bad storm.

That sparked a push to borrow $3 million to replace the copper roof with another that would last a century, but that fundraising ultimately grew into a much larger effort to modernize the historic structure. The price tag, after a $3 million contribution from Stephen and Tabitha King and a drive to raise the rest through community donations, was $9.6 million.

The glass atrium added to the front of the newer portion of the library — the addition built in 1997 — will be home to a lounge and a cafe run by Seasons restaurant in Bangor. The new business will be called Sage Cafe, and will offer coffee and snacks. McDade said it will be able to open as soon as atrium construction ends and the business sets up.

The children’s wing has moved to the third floor for improved safety. The library also has a new business center, allowing people to rent office and workspace for the day, week or month.

The library closed its doors for part of November and December as some of the most intense construction work was underway. Hard hats, sawdust and the smell of paint have been prominent.

Construction crews should wrap up the last of their work and clear out by the end of September, according to McDade.

In January, the library plans to host a formal dedication ceremony for residents and supporters, and hopes to see Stephen and Tabitha King among them, McDade said.

Follow Nick McCrea on Twitter at @nmccrea213.