Effective foam insulation for single-wythe concrete masonry walls

The objective of this study was to evaluate the effectiveness of three different methods to apply closed-cell polyurethane foam to single-wythe concrete masonry wall panels, namely, surface spray-on, filled formwork, and grouting the cores of the concrete blocks. Foams with two densities were applied at three different thicknesses. Two-dimensional heat flow simulations were conducted using THERM to determine the overall thermal resistance of the insulated masonry wall panels. Filled formwork application using normal-density foam yielded the highest thermal resistance. Hygrothermal analysis using WUFI Plus revealed that exterior application of the foam is preferred to avoid durability issues and take advantage of the thermal mass and fire resistance of masonry walls.