The company is advancing interior retrofit strategies for multi-wythe brick and other mass wall assemblies with integrated smart vapor control. These assemblies are prone to water penetration and capillary wicking, particularly at mortar joints and unit interfaces. When interior insulation is added, the temperature of the interior masonry wythe drops during cold weather, increasing the likelihood of condensation driven by vapor diffusion and air leakage.

Smart vapor retarders, such as the INTELLO PLUS membrane integrated with Smartrock, are designed to respond to changing ambient relative humidity. Under dry conditions, the membrane limits vapor transmission, functioning as a Class II vapor retarder. As RH increases due to construction moisture or incidental wetting, permeance rises, allowing inward drying. This variable response supports seasonal moisture management without trapping vapor within the assembly.

Paired with stone wool insulation, the system delivers thermal performance while maintaining drying potential—critical for durability in masonry retrofits. The approach helps mitigate freeze-thaw cycling, mold risk, and long-term material degradation. It also enables compliance with evolving energy codes without altering exterior facades, a key constraint in urban infill, lot line conditions, and historic preservation projects.

For more infomation, visit rockwool.com.