Auditorium Panels

Massive Panels Moved into New JHS

February 24, 2015

It’s delicate work, moving around 30-ton, 68-foot concrete panels.

These panels – rumored to be the largest of their kind in the state of Iowa – are forming the auditorium of the new Johnston High School. Piece by piece, the panels are placed by cranes to create the walls of the performing arts area. In total, it will take five weeks to complete the auditorium structure.

One of the first panels is put into place using a crane and a little manual manipulation. Each panel weighs approximately 30 tons and stands 68′ tall.

One of the first panels is put into place using a crane and a little manual manipulation. Each panel weighs approximately 30 tons and stands 68′ tall.

Beyond their size, there are a multitude of reasons to use the panels – they are easy to place, a cost-effective option compared to masonry blocks, and are able to bear weight well due to their sturdiness.

And while most construction workers are grateful for mild winter weather, crews at the new high school site needed frozen ground to install the panels.

“The panels go in best when the ground is frozen because it’s easier for trucks carrying the panels to get into the site, which keeps the construction advancing,” said Tim Kline, Buildings and Grounds Director and Construction Manager for the Johnston Community School District. “If the weather had continued to stay above the freezing point, we would have had to wait until April or May to get the panels installed.”

A wet fall slowed down the initial construction work, but a mild December allowed workers to pour concrete footings, start digging on geothermal wells, and pour the orchestra pit. In late December, crews began building the restroom cores, which are hardened or reinforced with structural steel for storm shelter. Wrapped with plastic and scaffolding, workers can continue progress even as the winter chill permeates the air.

“Midwest winters present challenges, but we’re using conditions to the best of our ability,” John Petersen, Project Manager for Stahl Construction. “In the coming weeks, people will be able to see a lot of the structural steel go up and start to form the building. It’s like a huge jigsaw puzzle, put together beam by beam.”

It will take about five weeks to put all the panels together, forming the auditorium. Stahl Project Manager John Petersen called it a “huge jigsaw puzzle.”

It will take about five weeks to put all the panels together, forming the auditorium. Stahl Project Manager John Petersen called it a “huge jigsaw puzzle.”

On a daily basis, there are an estimated 20 to 50 workers on site, doing everything from electrical work to moving the panels into place. Once enclosed, there will be 200-250 workers on site daily. Stahl said they are committed to keeping work and materials local; approximately 80 percent of the sub-contractors on the project are from Iowa, many from the Des Moines area.

“Things are beginning to take shape, which is very exciting for everyone involved,” said Kline. “There is a limited amount the public can see from the road, but the placement of these panels and the work on the core sections shows some pretty big steps being made. The new high school is an investment for our community and we’re pleased with the progress so far.”

The next major phase will be the deep foundation work for the gymnasium, expected in April. Approximately 600 aggregate geo-piers will be drilled into the ground, supporting the gym floor. Soil and structural engineers recommended the piers based on the size of the gym.

Watch for more construction updates and drone videos on the district Facebook and Twitter accounts  – something new is happening every day!