What Are Sandwich Panel Structural Insulated Panels SIPs?

The most common type of structural insulated panel is referred to as sandwich panels SIPs. Sometimes also referred to as stress skin or stressed skin panels, these panels generally consist of an insulating material, polystyrene foam, “sandwiched” between two outer “skins” of oriented strand board or OSB.  The two materials are laminated together with an adhesive or glue to form a combination panel with the outer skin material providing the “structural” part of the insulated panels.  Other variations of insulating and skin materials are occasionally available.  To learn more about Sandwich Panel SIPs, visit: www.sips.org


Why NOT Use Sandwich Panel SIPs?

    • Not Strong Enough - Not as strong as RAY-CORE SIPs.
    • Less R-Value - EPS Styrofoam has an R-value of 3.6 - 4.2 per inch. XPS Styrofoam has an R-value of 5 per inch.
    • Airtight? – Depends on careful attention to installation techniques and if not performed correctly the insulation panels OSB will rot, and lose their structural integrity.
    • High Failure Rate – Delamination, glue failures, rot, wall creep and roof sag plague the product and industry.
    • Availability - Special plans and costly engineering required by the sandwich panel manufacturer. Not produced until ordered and long production lead times.
    • Panels Might Meet Your Needs - Different thicknesses, lengths, and R-values are available.
    • Very Expensive - 1-1/2 times the cost of RAY-CORE SIPs. Often initial pricing does not include all costs. Substantial added costs for engineering and installation. Costly shipping!
    • Added Costs - Engineering, shop drawings, special code approvals and specially trained installers required.
    • Difficult to Use - Special training courses required with detailed installation requirements to build with.
    • Fast – Reduced construction time but costly installation costs
    • Heavy – 1 1/2 to 2X the weight of RAY-CORE Panels. A 4' wide by 8' long R-37 panel weighs 121 lbs. Less R-value, more weight. Cranes required and added shipping costs.
    • Fixed – Each piece has a number and a required location.
    • Unalterable – Onsite modifications difficult and will void engineering. Must wait for re-engineering and replacement panels.
    • Not Fire Safe- Low melt rate (have you ever thrown a styrofoam cup in a fire?) Should a fire occur, your walls will melt away and your house collapse. Use of HBCD flame retardants is hazardous to both humans and the environment.
    • Mold Problems - EPS and XPS foams are Semi-permeable foams, allowing moisture to penetrate with potential mold growth.
    • Environmental – Precut panels during manufacturing reduce job site waste, but waste is waste. Cutouts must still be disposed of at the manufacturer. In addition, the effects of brominated flame retardants added to the foam to reduce flammability are bioaccumulative and potentially toxic having a negative environmental effect.
    • "Green" – Helps to save energy, but can they be considered "green" considering the costs?


Heavy and Awkward to Move Sandwich Panel SIPs Structural Insulated Panels:

Sandwich Panel SIPs Structural Insulated Panels Heavy & Awkward

 Sandwich Panel SIPs Are Heavy and Awkward, With A 6 ½" x 8 ft. Panel Requiring Two Men to Move and Weights A Whopping 120 Pounds!