August 15, 2018 One of the main areas where conflicts exist is with trees that are near sidewalks. Swale trees, such as the live oak, need a lot of space for the trunk and root system to spread out. The more mature the tree becomes, the greater the risk of experiencing issues with roots spreading too close to a sidewalk. Generally, a tree that has reached its 10th birthday may become too mature for its allotted space and branch out, so to speak, resulting in a conflict with nearby sidewalks. Solutions that allow tree root systems and sidewalks to live in harmony are important for the environment, as removing the tree is neither healthy nor allowed in many cases. Sidewalk slabs can be shaved, evening out edges as a temporary measure. However, this is not a permanent solution to the problem. Conflict Damage Root systems are part of a living plant, which means they will spread out through the path of least resistance. The most likely point of damage in many cases is at the seam or expansion joint in sidewalk slabs. Obviously, this is damaging to the sidewalk and represents a danger to the general public due to tripping hazards from compromised slabs or protruding roots. Cutting the roots of a tree does not provide a permanent solution to sidewalk conflict in many cases. Roots can grow again under the same section of sidewalk or change direction and cause even more damage within three years of having been cut. It is important to also remember that the tree is still growing, which means there is a risk of escalating the level of damage by attempting to address the competing forces. Tree Stability Pruning roots is a risky procedure as it compromises the stability of the tree. If lateral roots are cut, the tree loses much of its resistance to strong winds and becomes especially vulnerable to uprooting in a storm. Cutting roots closer than 60 inches from the tree is not recommended in order to help ensure that a tree remains stable and balanced. This practice is the last result where no other feasible options are available to prevent root systems from damaging sidewalk slabs or roads. There is also an issue of liability for injury or damage should the worst-case scenario occur. Preferred Options Given that within three-to-five years a root system can experience renewed growth and wreak havoc on sidewalk slabs, root pruning simply is not the best option. There are preferred options that a professional arborist should explore to protect the tree, sidewalk, the general public, and private property. As mentioned earlier, shaving the sidewalk is one of the options that does not cause unnecessary damage to the root system. This process can be repeated a number of times before other options need to be explored. The idea is to even out the sidewalk using a technique that is cost-effective. Some arborists use asphalt to level out a sidewalk; however, this technique is not very aesthetically-pleasing as it results in a mismatch of materials. A relatively recent alternative to shaving is a technique called slabjacking. The technique involves injecting concrete under the slab to force it up so that it is level with an adjacent lifted slab. Slabjacking is basically a type of concrete leveling that is often carried out as an alternative to having raised or damaged slabs replaced. It is a useful technique when root systems are involved as it allows for correction of the slab while reducing the likelihood of permanently damaging the roots. Professional Arborist Root systems are complicated, which is why a professional arborist is best suited to make recommendations on preventing trees from causing conflicts with sidewalks that are used by the public. Other options may include solutions that allow the roots to grow without disturbing the sidewalk slabs above. Many of the techniques include excavation and simple solutions using materials that involve placing the sidewalk over a geogrid and gravel base. Adding structures such as a bridge or reinforced concrete may also solve the problem of root systems that get too close to the sidewalk for comfort. The main focus is to ensure that trees are able to thrive without causing a potential hazard to the public or resulting in frequent and costly maintenance. An experienced arborist will understand the root systems of a number of common species and provide expert consultation. If you are concerned about the trees on the edge of your property that are close to sidewalks, reach out to Front Range Arborists for help. We provide a service that is professional and friendly. Our first priority is always keeping your trees healthy, strong and out of harm’s way. Find out more about how Front Range Arborists can help provide services to residential, commercial, and municipal institutions with all of our Tree Services: Tree Pruning Stump and Tree Removal Shrub Pruning Fire Mitigation Fertilization Winter Watering Pest Control Tree Preservation
