Get it in writing! Do this as soon as the contractor proposes needed repairs. Oftentimes, a verbal quote can end up about 50% higher than the first estimated cost. It is also important to get three or more prices, to avoid paying extra for ‘emergency work’.
See the issue for yourself. Make sure the contractor can show you the issue with a video camera. Most contractors should have this equipment ready and available on their trucks.
Ask someone else. All too often, issues have different ways they can competently be addressed. Get a second and third opinion enables other companies with different approaches and equipment to offer repairs: sometimes without having to dig up your lawn. If digging is the only option, make sure permits are pulled for the proposed work, along with a copy of the inspection report when it is completed.
Do your research. Look into any contractor doing work on your home: Make sure they have a current license to perform the work they are proposing. Pull up their company website and check feedback from other customers. You can also check with the Better Business Bureau for their rating, ask around on local social media forums or utilize trade rating groups like Angi.com.