Root barriers are very useful in many different aspects when it comes to tree care. The root barriers themselves help prevent tree roots from growing into a variety of different structures, like drainage pipes, pool areas, foundations, and even sidewalks. They are extremely useful in helping to keep tree roots out of areas where they are not desired.
In the commercial landscaping, root barriers are often used preventatively to help keep tree roots contained in certain areas. For example, if you have large trees in a parking area, root barriers can be effective in helping to minimize the root system from breaking up new concrete down the road. Many times, for residential, we are called out after the homeowner already has an existing tree issue. Either their pool has cracked or they are having foundation problems. Roots typically do not grow underneath huge monolithic slabs but will grow around the perimeter pulling out the water and moisture from the ground. This can cause problems for the foundation. Many times, we install root barriers after the problems have begun to help prevent further damage and allow for repair of the issues.
There are many different types of Root Barriers available on the market. The one we use most often is made of a thin membrane material with nodules on it containing a product called “Trifluralin”. When properly placed this active ingredient creates a barrier that is very detractive to roots as they come in contact with the material. We dig a trench about four inches wide and as long as needed to protect the structure. Next, we dig to place the root barrier approximately 1 ½ to 2 feet deep. Sometimes you may need to place it deeper, depending on the type of tree species you are dealing with and the structure you are trying to prevent the roots from coming in contact with. The tree roots will detract and deflect off the barrier, preventing them from growing into the structure.
As long as you are outside eight to ten feet of the existing tree, this process is typically not hazardous to a tree. However, in some situations, it may not be recommended and we always suggest an evaluation by a professional accredited tree company. This is the standard recommended by ANSI for the majority of trees. You never want to cut roots too close to a tree on one side because you can cause significant stress to the tree and/or cause it to become unstable. When at all possible, it is always better to plan ahead for tree growth at your home or commercial property.
There are situations where root barrier isn’t the best solution. When two or more of the following situations occur, you will need to really rethink using this material. One, the base of a potential problem tree is higher than the protected hardscape. Two, if the soil is over 90% sand. Three, if the tree species is aggressive, like top-rooting varieties such as Maple, Ficus, or Cypress tree. Lasty, if the tree is closer than eight to ten feet from the protected hardscape.
