Root pruning is similar to pruning branches, and is done when roots are infringing on an area where construction is to be done, or when they are causing damage or safety problems to sidewalks, driveways, streets, and the like.
A callus will form at the cut, and new roots will generate from the callus. A Certified Arborist can determine which roots to prune and how much of the root system can be pruned without harming the tree.
After root pruning is accomplished a product called Bio Barrier can be installed which can prevent roots from growing further beyond a certain point. This product has a 10 year lifespan and can make an excellent alternative to tree removal given the right circumstances. A San Diego Tree Care, Inc. certified arborist can discuss your options and whether root pruning and Bio-Barrier will work for you.