DriTac has developed a repair system to correct the hollow spots and popping conditions for engineered wood flooring installations when other adhesives fail to get the job done. These defects cost the flooring industry millions of dollars per year. Studies and experience show that a major cause of these problems for engineered wood floor installations are adhesive voids between the flooring and the sub-floor. **DO NOT USE DriTac RS-1 engineered wood floor over sealed concrete. For repairs over concrete , use DriTac SW-1 Solid Wood & Bamboo Floor Repair Kit.DriTac Adhesive Refill - 32oz