“It was a curveball. We didn’t see this coming at all,” First Selectman Rudy Marconi said.

A $950,000 question on the town’s referendum ballot culminates months of work by town officials to deal with a problem that was years in the making, and hidden from sight: water damage inside walls at the 15-year-old Recreation Center.

“We were experiencing problems with the tile grouting and loose tiles in the locker rooms,” Director Paul Roche said.

“We had a couple of tile people come in and they said the problem’s much larger than what you expected — it’s not just loose tiles, there’s a problem with water permeating the walls and getting into the structure of the building.”

Architects and a contractor assessed the problems.

“We cut some access panels in the wall and did a lot of infrared camera work and found failures and leaks in many areas,” Roche said

“Much of the metal stud work had rusted and in some areas there were actually leaking pipe connections that were hidden in the walls,” he said. “The shower water was leaking through the walls into the space...

“What we thought was a repairable maintenance issue turned out to be a fairly significant structural issue.”

The center has 6,700 members, Roche said, and has been turning surpluses — over $175,000 last year.