The District 161 school board approved a process that it hopes will take care of the humidity problems at Flossmoor Hills School.

 At the special board meeting Jan. 29, a contract was approved for work on the school’s envelope, or the school’s barrier from the outside. Once that work is completed, a consultant will come to the school building to determine if the work met air tightness standards.

Staff at Flossmoor Hills, 3721 Beech St. in Flossmoor, have been dealing with ceiling leaks in classrooms. The problem was first noticed after air conditioning units were installed in 2020. The humidity and moisture problems are seasonal and are especially severe in July and August.

In October 2025, a consultant from Farnsworth Group told board members that the school’s envelope was operating at negative pressure. The building should have neutral or positive pressure.

That negative pressure is causing hot, humid air to enter the school as the building’s air equalized. The moist air gets caught between the roof and the ceiling, according to the consultant.

Pepper Construction won the $520,500 contract to make improvements to the school’s envelope starting in March. Associate Superintendent Fran LaBella said work will not involve the school’s walls, but will include work on the soffits and space between the building’s ceilings and roof. Plywood and insulation will be added.

Once the work is done, District 161 will have ECS Midwest conduct whole building air tightness testing to determine if the construction work has eliminated the humidity issues. The ECS Midwest contract is for $19,405.