Design, Installation, and Maintenance of a Root Barrier

To prevent tree roots from reaching the area at or around the foundation, a root barrier can be installed as follows:
Design of the Root Barrier - Consider the following to identify the areas that are, or will be affected by tree roots:

• The type and the future maximum height of the trees around your home.
• The type and the future maximum height of the trees located on your neighbor’s property.
• The location of patio, garage and driveway slabs you want to protect.

After consideration of these factors, the barrier should be run between this foundation and the tree or trees. The barrier should extend to a distance of the future maximum tree height from the base of the closest tree. For example, a large Bradford pear can reach 30 feet high and they have roots 30+ feet long. Trees located on an adjacent property can have roots that will reach your foundation. For example, a neighbor may have a large red oak tree that can easily reach a height of 80 feet, in the center of his yard some 50 feet away. You would need to install a barrier along two sides of your home 30+ feet long around adjacent corner.

Note: Do not cut roots too close to the base of the tree. Doing so may damage or kill the tree. Additionally, the ability of the tree to withstand a strong wind in a given direction may be reduced. As a rule of thumb, the barrier should not be closer than 10 feet to a large tree and 3 feet to a small tree or shrub. In some cases, a tree may have to be removed if it is too close to the foundation and prevents the proper location of the barrier. It is a good practice to use a soaker hose around the base of a tree after cutting the roots to install a barrier. Extra water will help reduce stress on the tree.

The root barrier should be located 5 to 6 feet from the foundation or slab area. The barrier should never be closer than 2 feet to the foundation to stay away from a close tree or a neighboring property line.

A tree will send roots as far as necessary to obtain sufficient water. Thus, failure to install enough length of the barrier can simply delay the time it takes for the roots to get to the water source. For example, if a barrier is only extended 10 feet along a driveway, the roots near the end of the barrier will take a sharp turn past the barrier and head to the foundation.

Identify and mark underground utilities to prevent damaging while trenching.

Installation of the Root Barrier – A narrow trench can now be dug and will allow for the installation of the root barrier material. The following specifics should be followed to ensure the performance of the barrier:

• The trench should be approximately 2 feet deep and allow for the installation of a 24 inch tall barrier material. The barrier material should be left sticking out of the ground and trimmed off flush with grade when complete.
• The barrier material should be a 1/32 inch thick rubber or a flexible PVC building siding material. It is important to use a rubber cement compound and liquid nail, respectively, and overlap each joint 2 to 4 inches to make a secure connection.
• The barrier should be continuous around the corners and have a minimum of 6 inches radius to minimize stress on the connecting joints.
• Return the soil and water-in to minimize settling.
• Trim the barrier material off at grade level.

Note: Caution must be used while digging, as underground electrical, piping, gas lines, etc. may be in the area.

Maintenance of the Root Barrier – The root barrier will be effective in preventing tree roots from removing the moisture from under the foundation, but will require some maintenance, as follows:

• Periodically (every year, or as noticed) inspect the area where root barrier was installed for roots trying to go over the barrier and cut, as needed.
• The area inside the root barrier and other areas that may not have a barrier should be watered periodically to maintain consistent soil moisture levels.