Serviceability of foam core structural panels based on bond strength Available to Purchase

Oriented strand board (OSB) face sheets adhered to polyurethane (PUR) foam have been used to make structural insulated panels (SIPs) for energy-efficient buildings for many years. One challenge for more widespread use is lack of a clear indication of service life and durability. Many regulatory agencies do not allow the use of SIPs without dimensional lumber framing, asserting OSB is typically not a principal structural member and citing a concern for service life. This paper presents the results of research focused on the evaluation of bond strength between the OSB skins and the PUR foam core as one measure of service life and fabrication quality. A total of 120 pull-off tests were conducted on panels subjected to various environments. A total of 120 tests were conducted on new to highly weathered, aged panels. Only 2·5% of these tests displayed partial debonding between the OSB and foam. Of the remaining specimens, 77·5% exhibited shear failure within the foam, indicating acceptable bond strength. The remaining 20% failed within the OSB skin. This paper discusses the findings and potential implications for service life of OSB skins and PUR foam core.