Problems With Concrete Over Tree Roots – What To Do With Tree Roots Covered In Concrete
Years ago, a concrete worker I knew asked me in frustration, “Why do you always walk on the grass? I install sidewalks for people to walk on.” I just laughed and said, “That’s funny, I install lawns for people to walk on.” The concrete vs. Trees, who have no voice to join the argument, are often the biggest victims of this battle. Continue reading to learn about concrete over tree roots.
Problems with Concrete Over Tree Roots
Concrete workers are not arborists or landscapers. Their expertise is in laying concrete not growing trees. When a concrete worker is at your home giving you an estimate on a driveway, patio, or sidewalk, that is not the right time or the right person to ask how the concrete will affect trees near the project.
Ideally, if you have large trees that you would like to keep safe and healthy, you should first call an arborist to come tell you the best location to place a concrete structure without damaging the tree roots. Then, call a concrete company. A little planning ahead can save you a lot of money in tree removal or redoing concrete.
Oftentimes, tree roots are pruned or cut to make way for concrete areas. This practice can be very bad for the tree. Roots are what anchor tall, top heavy trees in to the ground. Cutting major roots that are anchoring a tree can cause the tree to easily be damaged by high winds and strong weather.
Roots also absorb water, oxygen, and other nutrients that are essential to tree growth and development. If half a tree’s roots are cut off, that side of the tree will die back from lack of water and nutrients. Cutting roots can also lead to insects or diseases penetrating the fresh cuts and infecting the tree.
Root pruning is especially bad for older trees, although young roots that are pruned to make room for concrete patios, sidewalks, or driveways may grow back.
What to do with Tree Roots Covered in Concrete
Tree roots covered in concrete will not be able to absorb water, oxygen, or nutrients. However, professional concrete workers do not usually pour concrete directly on the bare ground or tree roots. Generally, a thick layer of gravel paver base and/or sand is put down, compacted, and then the concrete is poured over this. Sometimes, metal grids are also put beneath the gravel base.
Both metal grids and a layer of compacted gravel will help tree roots grow deeper, avoiding the gravel or grid. Metal grids or rebar used when pouring concrete also help prevent large roots from being able to heave the concrete up.
Oops, I poured concrete patio over tree roots by accident…now what?! If concrete has been poured directly upon the ground and tree roots, not much can be done. The concrete should be removed and re-done properly, with a thick paver base. This should preferably be away from the tree’s root zone. Care should be taken to remove any concrete from the tree roots, though the damage may already be done.
A close eye should be kept on the overall health of the tree. Trees do not usually show signs of stress or damage immediately. It can often take a year or two to see the effects caused to a tree.
Will Cement Kill My Plants?
In today’s home landscape cement is used to construct homes, driveways, even paver stones. Though it’s common to refer to concrete as cement, the two are not the same thing. Cement is one ingredient that makes up concrete. Small amounts of the concrete aggregate, which includes cement, can be dissolved by weak acids, such as rain, especially in areas where acid rain is more common. This problem is rare in most areas, and is unlikely to actually kill your plant. It may be sickened, however, if it is among the species that require an unusually acid soil to thrive.
Repair Tree Root Damage to a Paver Walkway
If you have a paver walkway in your garden, then nearby trees or bushes can lead to root damage. Roots get under the walkway and lift up the stones as they grow. This can also be caused by small weeds, which go in between the pavers and loosen the sand with their roots, causing the pavers to become damaged. One solution to this is to remove the tree completely before laying the pavers, but if you have accidentally suffered root damage, then you will need to fix the paver walkway to restore it. Fixing a paver walkway can be a time-consuming task, so it may take you a weekend to complete this project.
Step 1 - Dig Down
To access the part of the root which is causing the damage, you will need to dig down below your pavers. It is not a good idea to disturb the whole walkway just to get at one root, so use a simple chisel and mallet to remove the sand around the affected pavers. Then chisel away the sand and gravel below it, lifting it out with your trowel. You should be able to easily remove the laid walkway until you reach the cause of your root damage. Don't go too far across the walkway, otherwise, you may create an odd-looking path.
Step 2 - Remove the Root
Next, dig away the soil below your path until you get a good portion of the root above the soil. Examine at the root, and consider whether it needs to be cut to completely take it away from the walkway, or simply trailed back in a different direction. Most of the time, it is fine to cut a small root. You may need to saw off larger roots and place a metal guard against the stump so that it can not regrow. Use pruners to cut off the large root, and then place a sheet of metal in the ground, right against the root. You can check the root every year to make sure that it is not regrowing.
Step 3 - Repair the Ground
Now the root has been removed, you can repair the paver walkway. Start by replacing the soil you had to remove to get at the root, and then compact the soil. Mix in a layer of sand and compact it. Make sure that you are keeping a similar depth to the rest of the walkway. Press the gravel into place, and then add your new sand. This should all be level with the sand of other parts of the walkway.
Step 4 - Add the Pavers
Discard any pavers that were damaged by the root, and add new ones. Lay them in the sand, tapping them with the mallet until they are level with the rest of the walkway. Add more sand around the pavers, and then dampen the area so that the sand will set and form a hard basis for your path.
Creative Solution For Tree Root Problems – A Floating “Green” Patio
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It’s a battle in my garden – the maple tree roots versus me. They are powerful and I am often stymied as I cannot dig in the soil due to the deep and twisted mess that lies right below the surface. When installing my gate arbor, the workers ended up cutting the cable television (on game day no less) for the entire neighborhood because they had to use a power saw to get through the danged roots.
Gardeners often fight a lengthy battle with tree roots like I have, but perhaps there’s an interesting – and green – solution – – float a patio on top of the roots.
Below is a series of pictures that show how I used reclaimed sand, bricks, and stone (which would have gone into the landfill) to build a patio over the maple tree root mess I have in the back yard garden. You can also check out these outdoor guides if you want to add a few appliances like a gas/propane fire tank to give it a complete look. If you wanted something more permanent, you could certainly make a cement patio. However, I felt a “floating” patio would work better for this situation as roots grow over the years and I might want to add to the patio as well.
HOW TO BUILD IT – –
Step One – Dig a six to eight inch trench around the area you plan to put your patio. This will allow standing water to drain off of your patio.
Step Two – Cover with a permeable cloth cover of some kind which will allow water to drain through, but prevent worms from coming through and mixing the rock base.
Step Three – Arrange reclaimed material of all types in an attractive pattern on top of the fabric.
Step Four – Fill with a base of sand and rough gravel to help steady the reclaimed materials. I went to a big box store and bought all the broken bags of sand and rocks at a discounted price.
Step Five (no picture for this step) – Pour pea gravel over the top – I also used old half-empty bags from one of the big box home stores which I bought for super-cheap. The gravel makes the patio “less firm” in some ways, but it is quaint and a creative way to reuse materials that would have been thrown away.
I love the sustainable patio and maintenance is simply blowing the leaves off the top of the patio in both the spring and summer plus pulling any weeds that seed themselves from the top. It has been up now for several years and is very easy to take care of.
What do you think? Want to try building a green garden solution and save the landfill at the same time?
When Tree Roots Crack Your Plumbing
Roots grow into your plumbing because they find a small source of water, like a hairline crack or a loose joint, and they extend hair-like roots into it to access the steady flow of water and nutrients. You may not see the structural effects when roots grow into your plumbing, but you will experience the consequences.
Slowly flowing drains that don’t clear with flushing treatments
Completely clogged drains that don’t clear with a plunger, drain cleaner, or other treatments
Changes in water pressure
Most of the time, you don’t have to kill or maim your tree if it grows into your sewer system. Instead, call a tree-trimming expert to remove the portion that grew into the plumbing and call a plumber to replace the pipe. With proper sealing and repairs, your plumbing won’t seem appealing to your tree anymore.
Watch for the signs above and call your tree-pruning expert when they appear. You won’t be able to remedy the problem without professional help, especially if damage has already occurred. Have the arborist or tree-trimming expert help you with your trees, then call your local plumbing or construction contractor for repairs.
Re: Concrete slab over stumps
Thanks guys and I agree with you. I guess I was just looking for some affirmation. Bob made sense with the backhoe/excavator idea but the problem is that there will not be one. The construction process will just be auger drilled holes with a tractor and a concrete base poured for the posts to sit on(pole barn). That seems to be standard proceedure here in the lower part of Illinois. Actually most contractors don't even do that much but just set the posts on the dirt and fill hole with dirt. The building will be in the timber so before pad is poured it will be termite treated so I'm not really worried about "bugs" as Justin stated although that could eventually happen. I mainly do commercial work where everything is dug out and filled with CA6, compacted in 6" lifts, rebar, then concrete. So pouring over the bare ground and stumps kind of threw me for a loop. It's actually a "weekend/spare time" job as the "customer" is relation and doing alot of the work themselves with me helping out when possible. Thanks again pup
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