What To Do When Tree Roots Threaten Your Property

Concrete cracking due to tree roots.

If you’ve ever bought an older property with trees on it, you may have run into problems with tree roots. Often you’ll find that tree roots can damage both your foundation and your plumbing.

If there’s a problem with your tree’s roots invading your plumbing, its usually an easy fix involving scraping the pipe lines and then flushing some chemicals down the toilets to keep the roots at bay.

If you have a problem with tree roots disrupting your foundation it can be a little more difficult to deal with.

One of our projects in San Marino, California dealt with tree roots from two trees that had grown under the house. Over many years, the tree’s roots had lifted the house’s foundation by several inches. The lifting was so severe that cracks in the exterior walls and foundation were observed, and the windows of the affected room did not operate properly. The floor of the room next to the tree was noticeably uneven due to lifting of the foundation by the tree roots. The tree roots also lifted the adjacent concrete driveway and patio slabs.

In situations like this we often perform the following during an inspection:

1. Observe onsite foundation and surface conditions.
2. Excavate pits to determine subsurface conditions and the extent of the root intrusion below the property.
3. Prepare a floor level survey and site plan for the property
4. Prepare reports and plans to stabilize the foundations and remove the roots.

In this case we recommended that both trees should be removed, and all tree roots within 2 feet (on both sides of the foundation and below the foundation) from the house foundations be removed. After the tree roots were removed, we inspected the exposed foundations, and provided additional recommendations for foundation repairs.

Another case involving tree roots involved a two-story home that was built in 1975. The north side of the home had been experiencing foundation and slab movement for the past approximately six years.

Results of the floor level survey found that the north side of the home was about 3 inches higher than the remaining parts of the house. Only the living room and family room were affected, and the remaining parts of the house were within 11nch of level.

For this project, we recommended the following:

1. Install temporary sacrificial hydraulic jacks to support the house
2. Excavate soils and roots from below the footings to a depth of about 2 feet below the footings.
3. Remove the Interior slabs of the living room and family room. Remove roots from below the slabs.
4. Lower the north foundations about 3 inches.
5. Fill excavations below footings with lean mix slurry, and replace the Interior slabs.
6. Remove and replace damaged exterior patio slabs.

In both cases we were able to resolve the foundation issues related to the tree roots.

Have you ever had to deal with severe tree root problems? How did you resolve them? Let us know in the comments, below.

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Having problems with tree roots? Let us take a look. We’ll help you get evened out.