Planting new trees? Don't plant them less than three feet from paved areas. Try to plant trees no larger than 30 feet when adult if the areas between the sidewalks are less than 3-4 feet. For trees 50 feet and larger, try to have an area at least 8 feet or more between sidewalks. Install root barriers, typically plastic or woven geotextile fabric. This will drive roots deeper into the soil and away from the walkway.
Be very careful when trimming roots. Larger roots help support the tree and provide essential water and nutrients, so try not to cut roots larger than 2 inches. Cut as far away from the trunk as possible. Cut cleanly and mulch well. Remember, roots provide support to the trunk as well as provide the tree the nutrients it needs. Cutting roots can cause the tree to topple more easily by winds and even kill older trees in three to five years.
If you are concerned about cutting roots and the tree is in good condition, consider curved sidewalks. Remember to leave enough room around the trunk and roots. If the tree is in poor condition, you might want to consider removing the tree and repairing the sidewalk.
For minor sidewalk displacement of an inch you can consider grinding the raised edge down to level. For larger displacement, you can try patching the sidewalk with a cement wedge. Another option to consider is to remove a portion of the sidewalk, re-pour the concrete, and create a bridge over the roots. Sometimes it's best to just replace the whole sidewalk with other materials. Asphalt is cheaper and more flexible than concrete. Landscape pavers, while more attractive and expensive, still may fall to root damage but are easy to adjust and level. Rubber sidewalks are a new, greener alternative made from recycled tires and is both porous and flexible.
Taking care of your trees and sidewalks and lawns not only require lots of work but involve a little planning. By using these tips you can save yourself some stress and money.