MIDDLETON, Wis. -- Mold continued to be a problem Wednesday night at Kromrey Middle School in Middleton, delaying the start of the school year.

Crews are working to clean up the problem while parents and students wait.

Unlike other schools statewide, there were no buses or students at Kromrey Middle School Wednesday morning.

Instead, there were a few big trucks outside and a mold clean up crew, WISC-TV reported.

"I woke up and then I was like getting all prepared and stuff. And (my mom) just came up and told me there was no school, and I was like, 'Really?'" said seventh-grade student Matthew Wakai.

Wakai and his older brother Wesley, an eighth-grade student at the school, both have the rest of the week off.

They said they're not exactly upset about it. Their mother said she is more concerned with her boys' health than class.

"My oldest has allergy issues, so I wanted to make sure the air is clean before they go back. Better safe than sorry," said mother Danielle Wakai.

Inside the school, officials said they discovered a white, difficult to see mold last week.

"With something that's airborne, you can't really take the chance," said Middleton-Cross Plains Area School District Superintendent Don Johnson.

Johnson said it's not toxic, but the mold is an allergen and can cause problems for students or staff with respiratory issues.

"The floors are to be cleaned. The walls are to be cleaned. The ceiling is to be cleaned. The furniture is to be cleaned. There is some older furniture that has fabric that will be removed and discarded if it's at all questionable," said Johnson.

The school will be cleaned, tested, inspected and retested before classes begin.

"Our target is to be back in school Tuesday if at all possible," said Johnson.

The Wakai boys said they won't mind if it's a little later than that.

"Yeah, I'm pretty glad that I can have a few more days to sleep in," said Wesley Wakai

The cleaning crews will likely work through Friday, and if air tests are good, the school year will finally begin, WISC-TV reported.

Mold is a fairly common problem, but school officials said the timing was bad.

Johnson said that if the mold been discovered in July, school would have started on time.

School officials said the consultant they're working with has dealt with 40 buildings in the last six weeks.

Johnson said there have been similar mold problems with numerous schools throughout southern Wisconsin in the last few weeks due to the extremely hot and humid summer.

Meanwhile, the Lancaster School District said it has a mold problem under control. School officials said the problem was detected two weeks ago in some elementary classrooms after area rugs were shampooed.

Those rugs were replaced, classrooms were cleaned and air quality tests came back normal. Classes were held Wednesday in Lancaster as planned.