Library West reopened Wednesday morning after plumbing problems closed the building for nearly 15 hours on Tuesday.
Bill Covey, interim director for UF library support services, said the library was opened for regular hours on Wednesday at 8 a.m.
It had been closed at 5 p.m. Tuesday through the night.
Covey said he didn't know how many students were at the library at the time of the evacuation.
Eric Cochran, associate director of UF Physical Plant Department operations, said he thinks a "big wad of paper towels" flushed down a toilet probably clogged the sewage pipes, causing the library's west-side bathrooms on all floors to overflow.
"I don't know how much paper towel," Cochran said. "It's a four-inch pipe [in diameter], so that's quite a few."
All the bathrooms use the same pipes, he added.
At 5 a.m. Wednesday, three of the department's staff members started to remove sections of the first-floor's ceiling to access the clogged piping, he said.
He said the repairs, which would probably cost less than $500, would be covered by PPD as part of building maintenance.
Carpets soaked with water leaking from bathrooms on each floor were sanitized and not permanently damaged, he said.
With Library West closed early during a week filled with midterms, students found other places to study. On Tuesday night, UF civil engineering senior Gary Neal said he didn't think a plumbing problem warranted closing the whole building, but he wouldn't let it interrupt his studies.
"That's alright," Neal said with a laugh. "We don't need to go to the bathroom. We just need to study."
