When an overlay is applied properly and well-protected by a sealer or coating, it should last indefinitely, even under heavy foot or vehicle traffic. On floors, the use of a floor wax or polish can provide extra protection in high-traffic areas. The key is to reapply the sealer or wax if it begins to show some wear. Otherwise, wear patterns may begin to show, especially in colored surfaces.
For more information, see Concrete Overlay Maintenance.