While oriented strandboard (OSB) is increasingly accepted as a structural building product, its application in stressed skin panels (SSP) is limited because of a lack of engineering data for short- and long-term flexural behaviour. In 1986/87, 24 SSPs were constructed, six with flanges of Douglas-fir plywood, six with flanges of Canadian softwood plywood (CSP), and 12 with flanges of OSB. Half were tested for short-term (elastic) behaviour and the other half for long-term (creep) behaviour. Long-term creep testing was begun in February 1987 and continued through to 1989/90. This report presents the results of the 1989/90 testing, which continued measuring and recording test data for deflection, relative humidity, and temperature on the three types of panels; established model predictions for each type of load duration set up for each type of SSP; compared prediction and experimental results using accepted analytical methods and indicated whether the models can be used for accurate prediction of time dependent properties of the different SSPs; determined the value of model parameters that can be related to mechanical properties of SSPs and compared those results to those of other jurisdictions; and indicated the practical significance of the results for house performance.