60 Years of Research Builds Confidence in ThermaSAVE

Development of stressed-skin panels for building construction began in the 1930s. Engineering and durability testing was conducted at the Forest Products Laboratory (FPL) in Madison, Wisconsin, a facility operated by the U.S. Forest Service.

FPL tested the concept of using skins to carry a portion of structural loads by building a small house in 1937. Wall studs in the panels were 3/4” by 2 ½,” rather than the usual 2” x 4”. First Lady Eleanor Roosevelt dedicated the house, and the structure is currently a daycare center run by the University of Wisconsin.

FPL scientists reasoned that if skins could take part of the structural loads, maybe they could eliminate framing entirely. Engineering theory was developed and tested, and a complete structure was built in 1947 using corrugated paperboard. This structure was heated, humidified, and exposed to Wisconsin weather for 31 years. 

The structure was disassembled periodically for testing to observe changes in panel stiffness, and bowing was minimal. In 1961, expanded hexagonal paper cores were included in some of the panels, and in 1969, foam cores were introduced.

Today, typical structural insulated panels consist of a foam core with oriented strand board or plywood glued to each face. In 1984  H.H. “Hoot” Haddock founded ThermaSAVE Building Systems and brought the revolution of Cement Fiber Board SIPs to us today.

In 2005, ThermaBuilt, LLC was created to manufacture and distribute ThermaSAVE panels. With central production facilities ThermaSAVE Building Systems is ready to service the construction industry in the US.