concrete can move anytime, all the time, or it may never move. the key thing to understand about concrete is that it is only as good as the material underneath it. with that being said when you build your house and the excavator is backfilling the water, and sewer trench, and around the foundation it is important that he uses the right amount of water and compaction and brings it up in lifts so that it is tight going back in to prevent large settling in the future. concrete can also settle if the ground gets saturated among other ways. A house will typically settle for about the first 10 years, after that you may see settling but it is few and far between and often is due to waterline breaks for rain gutters spilling out too close to the house. Now with the knowledge of knowing how long your house will settle for you can make up your own mind as far as when to lift the concrete. if concrete is settling it is recommended that lifting it is a good thing to be proactive in protecting your concrete from cracking, and creating dangerous trip hazards. Concrete repair can be expensive but not nearly as expensive as concrete replacement, or being sued in court from someone getting hurt on your property. So remember mud jacking or polyurethane lifting your concrete, or even void filling is good to do anytime, but keep it mind that your concrete can continue to sink until the ground has found its final resting place.