Ask Mr. Smarty Plants

Quercus agrifolia (California live oak) is endemic to California; that is, it grows natively nowhere else. As you can see from this USDA Plant Profile Map, it does grow in Los Angeles County, so that is one consideration. We always try to check if a plant is native to where it is being grown, so we can be fairly confident that the soils and climate are right for that plant.

Follow this plant link, Quercus agrifolia (California live oak), to our webpage on this tree for more information.

You should read all of this article on the California live oak from this USDA Forest Service, which include height and width of the mature tree; especially this paragraph on root size.

"The root system consists of a deep taproot that is usually nonfunctional in large trees . Several deep main roots may tap groundwater if present within approximately 36 feet (11 m) of the soil surface . Coast live oak develops extensive horizontal root branches and surface-feeding roots. Tree roots in southwestern California are associated with mycorrhizae that aid in water uptake during the dry season. A network consisting of roots from 3 coast live oak trees and their and associated mycorrhizae covered a 50- × 13-foot (15- × 4-m) area of the soil profile that reached through weathered granite through to bedrock. Roots in clay soils were not infected with mycorrhizae."

Unfortunately, there is no doubt that 10 feet in either direction is not going to be far enough to prevent interference between the hardscape and the tree roots. It  might be feasible to transplant the tree still, but the question is, do you have someplace to transplant it to? You are still going to need a bigger space for the tree to prosper and to avoid damage to structures. Transplanting any tree is difficult and, in this situation, more so. We found a Mr. Smarty Plants previous answer on transplanting Quercus agrifolia (California live oak). We suggest you read it, and then decide if you want to move it. No matter what, if there is nowhere to put the tree, there is no point in struggling with it.

Oh, yes, and about the sprouts off the roots of your oak. You can tell we answer a lot of this kind of question because here is another previous Mr. Smarty Plants answer on that very subject. And, if you remove that oak, sprouts are still going to come up out of roots in the ground. Every plant is agreed on one thing: It must survive.