Root Barrier Installation in North Richland Hills, TX

Root barrier installation is a way to limit how far a tree's roots reach under a foundation. Trees rarely push a house up or crack a slab directly. A review of tree root research published by the International Society of Arboriculture in 2014 found that roots near shallow foundations on shrink-swell soils can draw down soil moisture during drought, so the soil shrinks and the foundation settles and cracks. On clay soils like those found around the Metroplex, a large tree close to the house is a moisture problem as much as a root problem.

How far roots reach

The same review cites the Kew Tree Root Survey of more than 11,000 trees in England, where recorded foundation damage was on average 2.5 meters from cypress trees and 11 meters from poplars, with most species between 5 and 7 meters, roughly 16 to 23 feet. Species and soil matter, so a tree well away from the house may still be worth a look if the slab nearest it has dropped.

What a root barrier is

A root barrier is a vertical sheet of rigid plastic or another root-resistant material set in a narrow trench between the tree and the foundation. Roots that reach it are turned downward. The research is specific about installation: the top edge has to sit above grade, depth makes a difference, and short barriers can be bypassed because deflected roots tend to resume their original direction once past the end of the barrier.

The honest limits

Barriers are not a cure-all. The ISA review notes that roots can grow over or under a barrier that is not installed correctly, or through cracks that develop over time, and it states that controlling roots with barriers alone 'is not considered an acceptable solution' for tree-related subsidence. It also reports that pruning does not reliably reduce a tree's water use, and that removing the tree is the only sure way to stop tree-related subsidence from coming back. A barrier is a reasonable step when you want to keep a tree and reduce its pull on the soil under the house; it is not a certain fix.

Talk to an arborist

Cutting through roots to install a barrier can stress or destabilize a tree, especially when the trench runs close to the trunk. Before we cut, we recommend getting an ISA-certified arborist's opinion on the tree's health and how close a trench can safely go. If removal is the better choice for the house, a tree service handles that.

Barriers as part of a repair

When a foundation repair is done next to a large tree, a barrier can be installed at the same time, since the area along the beam is already excavated. Combined with even moisture around the foundation in dry months, it can help the unpierced parts of the slab stay steadier.