Long recognized as a durable, fast and economical building solution, the selection of site cast Tilt-Up for prisons is a growing trend. With concern for safety, security, maintenance and energy efficiency always at the forefront, owners of today’s correctional facilities are turning to insulated site cast Tilt-Up wall panels to meet these needs. Innovative Tilt-Up contractors are collaborating together with sandwich wall insulation system suppliers to target this market. A recent penitentiary and prison project in Tucson, Ariz. demonstrates the success of sandwich panel Tilt-Up in addressing a prison owner’s needs in a timely and cost-effective manner.

Why Sandwich Wall Tilt-Up?

Since 1984, Composite Technologies Corporation (CTC) – the manufacturer and distributor for the Thermomass® Building Insulation System, has been active in the correctional facilities market. The Thermomass® system is a patented continuous fiber composite connector that is used to structurally tie two layers of concrete together through predrilled, prefabricated, extruded Dow® brand insulation products. Known for its energy efficiency, this system was a natural fit for the prison marketplace.

“Since most correctional institutions are government-owned entities, they must be concerned with not only securing the resources to construct the facility, but also having the funds to operate it,” said Tom Stecker, President of CTC. “As such, energy efficient structures are a must in this industry.”

“Performance” of the exterior concrete walls is the key element of success for Tilt- Up as an efficient insulating option. Concrete that is located adjacent to controlled interior spaces dampens the temperature swing that is normally experienced as daily temperatures rise and fall. This dampening effect can result in substantial energy savings due to reduced HVAC capacity. Essentially, the mechanical systems don’t have to work as hard to control the temperature. The same quantity of energy may need to be removed or added, but it is done so over a longer period of time. In the cooling mode, thermal mass reduces temperature swings by storing energy during the build-up phase, typically afternoons, and then releases energy during cooler periods, such as evenings. This ‘thermal mass effect’ is more pronounced in temperature zones where it gets too hot during the day, yet cools down nicely at night. In the heating mode, the walls store energy from the building’s heating system and release it back into the space.

The large, Tilt-Up concrete panels also add to the energy efficiency of a Tilt-Up structure since the panel size reduces the number of joints between panels, which in turn reduces air infiltration or leakage into and out of the building. Air infiltration is a large source of heat loss.

The Thermomass® Building System has proven to reduce a facility’s energy costs by as much as 50 percent or more. Thermal testing programs, commissioned by CTC and conducted through Oak Ridge National Laboratory and Construction Technologies Laboratory, provide the necessary data to validate that Tilt-Up sandwich panels, when constructed with a complete separation between concrete layers, develop significantly higher thermal performances than traditional methods of construction and other sandwich systems that use metal connectors or solid sections of concrete to tie the concrete layers together. According to Stecker, an R value of 30 is possible with as little as two-inches of insulation using the mass effect of the concrete sandwich wall. Load bearing Tilt-Up sandwich panels eliminate the need for redundant structural steel around the perimeter of the facility. Additionally, the Tilt-Up sandwich panels with integral insulation can eliminate the need for additional interior and exterior finishes, which also c ntributes to lowering the overall cost of the project.

Beyond energy efficiency, security and maintenance are also crucial considerations for correctional facility owners. For example, according to Stecker, it is common for prisoners to pick at the joints in a masonry wall – placing a tremendous maintenance burden on prison facility managers. With minimal joints, Tilt-Up is an obvious solution. Further, with growing concerns about indoor air quality and mold, moisture concerns are paramount. Correctional institutions must address this issue head-on and seek building systems that have a long-term reputation to standing up to moisture. Tilt-Up panels that utilize the Thermomass® system can eliminate moisture penetration throughout the panel, as well as condensation on the inside of the wall. The system prevents cold spots on the wall, which eliminates condensation on the walls.

Another benefit that the Tilt-Up system affords correctional institution is speed. Many of these projects have fasttrack schedules and Tilt-Up has proven performance in meeting tight schedules cost-effectively.

Wendy Ward, Vice President of Constructive Communication, a public relations firm specializing in the design and construction industry, serves as a marketing consultant to the Tilt-Up Concrete Association. For more information about the growing tilt-up method, visit www.tilt-up.org. Ward can be reached at wward@constructivecommunication.com.