Series of full-scale tests were conducted on polyurethane foam-core Structural Insulated Panels (PUR SIPs) to study the load response and creep behavior of such panels. The load response of PUR SIPs was compared with conventional stud wall panels. The effects of de-bonding between the foam-core and the OSB face-sheets were also studied to understand the effects of such change on the overall performance of PUR SIPs. At last, computer modelling was employed to simulate and predict the behavior of PUR SIPs in different loading orientations and dis-bond ratios. It was found that PUR SIPs can outperform conventional stud-wall panels in every aspect. In the case of 165 mm (6.5 in.) thick PUR SIPs, 33% dis-bond between the PUR foam-core and the OSB face-sheets caused an average of 64% reduction in ‘axial load’ capacity, an average of 75.8% reduction in ‘transverse load’ capacity, and an average of 7.9% reduction in ‘racking load’ capacity of the panels compared to brand new fully-bonded SIPs. It was also found that 33% dis-bond in 165 mm (6.5 in.) thick PUR SIPs has minimal effect on the racking load capacity of the panels. In the case of 114 mm (4.5 in.) thick PUR SIPs, 33% dis-bond be-tween the PUR foam-core and the OSB face-sheets caused an average of 63.3% reduction in ‘axial load’ capacity, an average of 79% reduction in ‘transverse load’ capacity, and an average of 29% increase in ‘racking load’ capacity of the panels compared to brand new fully-bonded SIPs. All tested panels satisfied the code requirements for the creep deflections (span/180) and they fully rebounded to their initial estate, 90 days after removal of the simulated snow loads. It was also found that weathering has minimal effect on the bond between the face-sheets and the PUR foam. After computer simulations of fully-bonded and dis-bonded PUR SIPs in two different thicknesses, it was found that SOLIDWORKS simulation software is a useful tool to predict the load response of PUR SIPs only when fully-bonded panels are exposed to transverse load orientation regardless of the thickness of the panel.

In general, available Canadian and American standards were followed in this study. Where applicable, standards were adopted from other material testing methods for testing PUR SIPs. It is believed that this independent research has addressed most frequently ex-pressed concerns regarding the use and application of structural insulated panels such as de-bonding issues and creep behavior and their relationship to durability. The hope is that is research help increase the use and application of SIPs in green, high-performance, light-frame building construction in Canada.