TEC Specialty Products Inc. recently introduced Smooth Start, a cement-based underlayment that dries to a walkable surface in four hours or less. According to the company, Smooth Start is designed to level from featheredge to 1-inch deep in a single pour. The underlayment can be used with ceramic and natural stone tile, carpeting, resilient tile, and wood flooring. The company recommends using Smooth Start for leveling concrete and cementitious surfaces, cementitious backer units, exterior grade plywood, and oriented strand board