One area of research involves the evaluation of polyurethane grouting technology that is commonly used to stabilize fractured mine roof strata. Concurrently, NIOSH is conducting work to evaluate the application of ground penetrating radar (GPR) for advanced delineation of problematic mining areas. In this study, NIOSH partnered with Sub-Technical, Inc., who injected a polyurethane grout (also known as glue) into a roof area of NIOSH's Safety Research Coal Mine. The mine roof area was scanned using GPR technology before and after grout injection in an attempt to determine the extent of grout infiltration.