House Construction

Why Are SIP Wall Panels So Strong?

SIP fact: Homes built with structural insulated panel (SIP) walls are approximately 2.5 X stronger than standard stick-framed structures.

SIP wall panels are, by design, load-carrying panels that consist of expanded polystyrene (EPS) rigid foam insulation inserted between two sheets of oriented strand board (OSB). The resulting “SIP sandwich” is incredibly strong, providing superior compressive resistance and flexural strength in the field. And what’s to credit for SIPs’ mighty strength? Their structural design, which resembles that of a steel I-beam, allows a SIP to shoulder in-plane compressive loads evenly. When combined with their proven manufacturing process, SIPs can stand strong for decades. Here’s how these high-performing panels assume their structural integrity.

SIP wall panels harness the ingenuity of steel I-beam design

An integrated building product, SIP wall panels can provide both structure and insulation in one package. Take a closer look, and the structural properties of a “SIP sandwich” resemble a steel I-beam. The OSB act as the flange, resisting most of the bending movement. The rigid foam core acts as the web, which effectively absorbs shear force. This engineered design ensures that the panel can shoulder impact evenly. Equipped to easily disperse loads, weight-bearing SIP wall panels can provide an appropriate amount of stiffness and flexibility to effectively sustain compressive forces.

SIP wall panels rely on a specialized fabrication process

A “SIP sandwich” also inherits its impressive strength and impact resistance from a carefully engineered manufacturing process. A manufacturer like Extreme Panel will use an automated laminating press to apply adhesive and stack the material, square it up, and then press the SIP. In doing so, ensuring the bonding material has penetrated and set completely. And as a result, the integrated nature of the SIP will make for a stronger, more unified system.

The continuous bonding of the EPS insulation to the oriented strand board (OSB) also delivers incredible strength. In fact, an 8-foot high by 6.5-inch thick SIP can effectively resist up to 70 pounds per square foot (PSF) of side load, such as heavy winds. The same SIP can resist 4,250 pounds per lineal foot (PLF) from a floor or roof load. With this level of ingenuity, SIP homes can stand strong.

Need another quick fact to take with you? SIP homes constructed in the 1930s are still standing today, a testament to their tried-and-true design and fabrication process. Learn more about shoring up your home with SIP wall panels at

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