What To Do When Your Tree’s Roots Are Destroying The Sidewalk

What To Do When Your Tree’s Roots Are Destroying The Sidewalk

All too often, the big, beautiful trees that line Portland’s streets tear apart the sidewalks that stretch over the roots. As tree trunks expand and roots grow stronger, the concrete sidewalk slabs frequently crack and lift, tripping passersby and making a mess of our neighborhoods.

If this is happening on your property, you may have already received a notice from your local government requesting that you repair the sidewalk as soon as possible. However, higher-than-expected bids from concrete contractors can sometimes be discouraging, especially when there’s a good chance you’ll just have to do this all over again in a few years.

Unless you want to keep repairing the sidewalk, you should look for a solution that gets to the root of the problem. While there is no concrete solution for this inevitable, frustrating situation, there are good and bad ways to handle the mess and control the tree’s roots.

What You Can Do to Keep Roots From Damaging the Sidewalk

Tree roots damaging the sidewalk.Sometimes it’s best to just remove the tree and start over. Just make sure you get permission from the city first. Cutting down the tree may not be enough to prevent root growth. You’ll also need to get rid of the stump because roots may continue to grow. Grinding is the best method of quickly getting rid of an old trunk. We grind up to 18-inches deep, getting rid of the entire stump. When you grind the stump, you plant on the site immediately.

If removal isn’t an option, look for a concrete contractor. Finding the right concrete contractor will have a big impact on the outcome of repairing or replacing your sidewalk. When you shop for bids, make sure you’re contacting companies that have previously come out on the winning side of the roots versus sidewalk battle.

Your contractor should have more than a few tactics that they can use to fix the problem and prevent a recurrence. Some effective methods are:

  • Putting down a layer of pea gravel under the new concrete allowing the roots to expand.
  • Reinforcing the concrete with rebar so the roots have to lift several slabs at once to cause damage.
  • Creating a sidewalk that bends or slopes around the tree, giving the trunk and roots room to grow.

An honest, experienced concrete contractor will explore all of these options with you.

What To Avoid When Battling Tree Roots

Tree roots can damage a sidewalk.Getting rid of roots isn’t straightforward. Trees need roots to gather water and nutrients. Taking the wrong approach may be ineffective at best and harmful to your tree at worst. Here are four things to avoid:

  1. Don’t wait. The city will generally give you an extended period of time to address your sidewalk problem. That’s because all the arrangements, permitting, and actual work can take a while. Get started now before you’re under the gun.
  1. Don’t cut the roots. Only an expert should attempt to cut tree roots. Some species die after losing even a small fraction of their roots. If tree roots need to be cut, they must first be marked by the city’s arborist. Without this approval, cutting roots can easily damage or kill a tree and earn you a hefty fine. Plus, if done incorrectly trimming roots will harm your tree and make it more likely to weaken or even topple. This also applies to the ineffective method of carving an “X” on the top of a root. Excessive root pruning is often expensive and alone will not solve your problem as studies have shown that sidewalks will lift again within an average of five years.
  1. Don’t use growth inhibitors. When you use tree growth inhibitors, energy that normally goes to the development of the tree’s crown is redirected to the root system, which will obviously make the problem worse.
  1. Don’t assume the concrete has to be replaced entirely. It can be costly to replace an entire section of a sidewalk, so consider any other options your concrete contractor might have, such as patching.

Plan Ahead Next Time You Plant a Street Tree

Like with most problems, the real solution begins with prevention. The species of tree that is planted will be the biggest determiner of whether you are going to have root-and-sidewalk problems in the future. Some species are prone to invasive roots. These trees may damage sidewalks, wreak havoc on your plumbing or even invade the parts of your home.

The City of Portland and many of the surrounding cities can offer a handy list of tree species that are appropriate for planting between the street and the sidewalk which should all work just as well near any sidewalk or driveway.

You’ll need a permit before you plant. The permit is free and includes an inspection. The inspector can advise you about planting locations and suitable species for your site. When you choose the right tree, you decrease the risk of problem roots in the future. Visit Portland’s website to learn about permits, tree lists and more.

Other cities around Oregon and Southwest Washington may require a permit. Check with your town’s public works department to find out what’s needed.

You can install a root barrier when trees are young to direct root growth. Barriers consist of either fabric or plastic. You’ll need to dig a trench to buy this underground fence. Bury the barrier between the tree and sidewalk, 18 to 24 inches deep with a width of at least five feet. The barrier redirects roots to grow deep under the sidewalk, eliminating the heaving caused by roots just under concrete.

Contact Portland’s Most Knowledgeable Tree Service

Do you need a removal estimate or more advice about your trees? Contact Inexpensive Tree Care today.

Last updated Dec. 19. 2016. Originally published August 19, 2013.

Inexpensive Tree Care
Inexpensive Tree Care
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