An analysis of cracking problems during construction of a second-floor addition at Amherst's Windermere Boulevard Elementary School shows the situation is correctable, but far more complicated than officials originally thought.
The results of an independent structural analysis, using a three-dimensional model and conducting an on-site study, indicate that under a wind load the addition is "drifting" by 2 to 3 inches.
A deflection of about half an inch would be normal, according to Thomas R. Kiener, president of Jansen/Kiener Consulting Engineers. The company conducted the study at the request of Foit-Albert Associates, architects on the project.
"The good news is I don't believe anyone is in danger," said Kiener, who discussed the matter at Tuesday's School Board meeting. The school has been using the first floor while construction continues on the second-floor addition.
Completion of the second floor, originally scheduled for last fall, was delayed when cracks appeared in a material used to level the rough concrete roof slab in preparation for the installation of flooring. There was also some cracking in partitions and bricks.
As a solution, Kiener recommended adding cross braces between the building's first and second floors. The cross braces would be buried in the walls, said Kiener, noting that the fix would involve taking down drywall and relocating mechanical and electrical items. The cross bracing would be completed during the summer months when students are not in the building. It is possible that the flooring and other second-floor projects could be completed in the same time period and the addition ready for use this fall, Kiener said.
"We're not happy about this, but at least it's a solvable problem, and it's safe for kids right now," said School Board President Paul V. Batt Jr.
Other discussion centered on Kiener's comment that the cracking problems are twofold. He said the cross bracing solution may solve problems associated with cracks in the partitions and brick, but there could still be small cracks in material used to level the concrete roof slab.
Kiener said he is not particularly concerned with this "micro-cracking." He said the cracking doesn't affect how much load the floor can carry. "We're just talking about serviceability," he said.
Mark A. Whyle, the district's director of administrative services, said the problem will likely mean a design change involving the installation of carpet in areas where the school had planned to have tile or terrazzo floors. He said those floors are "less giving."
Plans already called for carpet in the classrooms. Whyle said the district's next step involves putting Foit-Albert to work on design changes and cost estimates and having Ciminelli-Cowper, the addition's construction managers, draw up a construction schedule.
"We're going to start a new capital project initiative on this particular piece," said Whyle, who refused to speculate on the cost of making the change or how the district would pay for the project.
The 12,000-square-foot addition, which includes six regular classrooms as well as multipurpose and special-education rooms, is part of an $8.1 million districtwide capital construction and renovation project that was largely completed last fall.