Sulfur is a plentiful, low-cost, unique material whose physical properties can be altered and employed in structural applications. This program was undertaken to develop an optimum sulfur-based formulation for use as a coating to both seal and support mine walls. The initial effort in this research was devoted to a laboratory study of the physical and mechanical properties of a variety of sulfur-base coatings that were specifically formulated for this application. Concurrent with formulation development, laboratory equipment and techniques were developed for spray application of the sulfur-based coatings to the ceiling and walls of a structure that simulated the interior of a mine. One hundred parts of sulfur modified with 10 parts of talc, 3 parts of milled glass fiber, and 2 parts of dicyclopentadiene was found to be a fire- retarded, low odor, low eye irritation, sprayable formulation for sealing and strengthening mine walls.