There are many things that can do damage to your cement walkways. When the ground freezes and thaws it moves around making the cement crack. It could also be from tree roots growing underneath it. It could even be something as simple as the cement sinking in from its own weight or due to a poor job done in preparation before it was poured. Whatever the cause, you might think that your only way to fix it is to have it ripped out and a new cement walkway poured in, but it could be that you could go with a cheaper alternative called mudjacking. Mudjacking is performed by drilling several holes into the existing cement and then pumping in a mixture of cement water and soil to level the walkway. If there are underlying pipes, powerlines or gas lines where the walkway is located, extra care needs to be exercised to make sure they aren’t damaged in the process.