Concrete, like other construction materials, expands and contracts with moisture and temperature changes. These changes produce cracks in hardened concrete unless they are properly controlled. Making provisions for this problem, such as installing concrete control joints, prevents a concentration of crack-producing stress forces. Control joints eliminate unsightly random surface cracks from forming by gathering, distributing, and dissipating forces resulting from temperature and moisture variations. Mar-flex’s Control Joint System is designed to ensure optimum protection, with a watertight outside control joint which is created when filled with Mar-flex’s Waterstop Elastomeric Sealant and protected by Mar-flex Fiberglass Fabric Reinforcement. Basements require foundation walls that are watertight and waterproofed. The Mar-flex Control Joint System provides an economical, easy to use system for eliminating these cracks which are unavoidable, uncontrollable, unsightly, and will leak water if not properly planned for ahead of time.