If you have an older house and it has cement sidewalks, you might be experiencing how they will star sinking and become uneven, this is not just unsightly, it can also be a safety concern.
You might worry that you will need to spend a lot of money to tear out the old slab and then pour a new one, but this is not the case.
There is a procedure called mudjacking that will solve the problem at a lower cost and with less labor. The procedure is done by drilling holes in the concrete and then pumping a mix of cement, soil, water and other materials into them to fill gaps and raise the concrete back to its original location.
This is a fairly easy procedure, but it is always better that a trained professional performs it to make sure no damage is done to possibly underlying pipes and utilities.