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There Are 5 Different Ways Tree Roots Can Damage Your Home
Tree roots can cause severe damage to your house in five main ways. I’ll explain each of these below and include some real-life examples of related damages I’ve seen.
Way #1: Intruding Roots
Most homeowners don’t understand just how far out a tree’s root system spans. You know how big the canopy is, with all the leaves and branches? Well, some species grow roots twice that width!
The problem with not understanding this is that property owners think it’s okay to plant trees close to their homes. After all, they provide shade and keep your house cooler in the summer, so it can’t be all bad, right?
Tree roots are tough little things that force their way through hard-packed soil, rocks, and even solid concrete. I think you see where I’m going with this. When faced with the challenges of pushing into or even through your foundation, tree roots will prevail!
As inspirational as that might sound, it means serious problems for you and your home.
If you have a basement or crawlspace, the tree root cap can bow the foundation wall inward, eventually causing it to crack. Not only will your under-home area be open to moisture and insects, but the wall might lose its structural stability and fail to hold up your home adequately. In case this isn’t clear, your house could collapse if the damage gets bad enough.
Just to give you an idea of how serious this is, the average cost to fix a damaged basement wall is around $4,500! I did work at a house once where we found that a major root from a nearby tree was growing between the footing and the wall for about 8 feet.
That homeowner had the unfortunate experience of having to jack up the house, remove the wall, footing, and tree root, and then replace both the wall and the footing. She also had to remove the tree when all was said and done, and her total was over $15,000!
You can also have issues with the roots growing under your home if you have a concrete slab foundation. As the roots grow in length and width, they’ll begin to force your slab upward. This can create an uneven floor and cracks in the slab, issues that commonly come with water intrusion and the need for structural stabilization.
A friend of mine bought a house that had a sunroom — something he dreamt about having for years beforehand. Eventually, he realized that the floor in the area was uneven, so he pulled up the flooring and found a large crack in the slab.
A few calls to foundation contractors later, he discovered that the crack and the resulting unlevel floor were caused by a tree root growing under the slab. He went with the cheaper of two options for fixing it, which involved adding new supports for the flooring and bypassing the damaged slab.
This more affordable solution still cost him $7,500, and it wasn’t even permanent. The other option was over $17,000, though, so…time to give up the dream and sell the house before more problems arise!
Way #2: Soil Moisture Fluctuations
Even if your tree roots don’t push through your foundation, they can cause severe problems just by being near the concrete. That means that the oak tree 30 feet from your house could still cause problems for your foundation!
Let me explain…
Your concrete foundation requires pressure from surrounding soil to help keep it stable, but it’s a fragile balance. If the pressure becomes too intense — either from expanding soil or intruding tree roots — the wall will bow inward, sometimes to the point of cracking.
Alternatively, if the pressure required from the soil decreases, the wall can bow outward. Expansive soil, which contains a high concentration of clay, is subject to some pretty wild volume fluctuations.
Why? One word: moisture.
As clayey soil gets saturated, it expands; when it loses moisture, it shrinks.
You might be wondering: what does this have to do with tree roots? Well, trees intake water, right? Through their roots? And the water comes from the…?
Soil. That’s right: tree roots near your foundation can soak up all of the water around the concrete and cause the dirt that usually supports the concrete to shrink. This leaves the concrete without the necessary support, and it can crack and even collapse if the issue is severe enough.
My sister-in-law moved to Houston for a job opportunity, and she was renting an entire home while she got situated and looked for a permanent residence. The house she was renting had pretty much all the symptoms of foundation issues: cracks in the siding, a chimney pulling away from the outside, doors and windows that wouldn’t close easily, and buckling floors in some rooms.
It wasn’t her business or mine, but we did some investigating and found that the issue was likely caused by the tree roots surrounding the house. The property was gorgeous, with massive trees providing shade and natural beauty all around the house. Under the ground, the situation was less appealing.
Especially in a place like Texas, where drought conditions are common, tree roots can soak up all of the available water in the ground and leave the soil to shrink away from the foundation. Eventually, this will mean thousands of dollars in repairs, if not tens of thousands.
Luckily, she moved out before any structural instability became too severe, but I do kind of wish she had stuck around long enough to get a contractor in for an estimate!
I have a friend in the Houston area that does foundation repair. He couldn’t get to this particular house before my sister-in-law moved, but he told me about another home that had sunk about 7 inches into the ground because of tree roots soaking up all of the soil moisture and causing the structure to settle. An incredible 40 push piers, $9,500, and one ruined lawn later, the problem was solved. Easy!
Way #3: Cracked Slabs from Root Rot
Let’s say your trees grow roots under your concrete slab, and somehow, you don’t experience any problems with them pushing the concrete upward or creating moisture problems around your foundation. Lucky you! Well, maybe. You’re still at risk of damage from root rot.
Let me explain…
Once a tree dies, it slowly decomposes, roots and all. Over the course of a few years, the wood rots and the soil above and around it will collapse inward once the roots are no longer strong enough to withstand the pressure.
If the roots are large enough, you’re looking at a pretty significant void beneath your foundation, which could leave a substantial portion of the concrete unsupported. As I mentioned above, your home’s foundation relies on the pressure from the soil around it, so once that pressure is relieved due to a rotting root, the concrete can crack.
Worst case scenario is you’re met with a loss of structural integrity, and instability beneath your slab is one of the most challenging things to correct. You’ll likely be paying thousands for excavation and installation of supportive push piers.
Way #4: Termite Damage
Even if the rotting roots of a nearby dead tree aren’t a problem, the stump can be if it’s close enough to your house. Decaying wood will undoubtedly attract pests that can infiltrate your home and even feed on the building material.
The worst offender? Termites.
Termites are attracted to rotting wood and will happily move on to the next readily available food source once they’ve consumed the stump of a dead tree. While they won’t feed on your foundation, they can move into your home through gaps between the concrete and the framing above and get to work.
The worst termite situation I’ve ever heard of occurred because of a dead tree and firewood left near an abandoned foreclosed home. Presumably, the termites had years to chow down, so they were able to do some severe damage.
When a friend of a friend bought the home to renovate and flip, they didn’t quite know the extent of the termite problem. When they began the repair process, they found beams in the basement that were supporting the house that they could literally push their finger through. I remember seeing a video of them squeezing the rafters, which hold up the entire house, and just seeing the wood crumble because it was so severely weakened by termites.
They went on to discover that the framing throughout the entire house was compromised, as were the wood floors, roof rafters, and just about every other inch of wood. They ended up having to tear down the house and rebuild it from scratch. All in all, a few years of termite damage ended up costing over $250,000!
Way #5: Plumbing Issues
In case you’re not convinced yet that hidden tree root problems are terrifying, there’s one more area of your home they can attack: plumbing lines.
Since tree roots are strong enough to penetrate solid concrete foundation walls, it should come as no surprise that they can also push through plumbing lines and sewer lines. That’s right, even those massive, cast iron sewer mains!
Most articles you can find online about tree roots causing plumbing damage explain that the roots can push through the pipes and clog them. This is true, but there’s more to the story. There are really two potential problems tree roots can cause for your plumbing lines.
First, root systems can infiltrate plumbing and sewer pipes that run underground. They grow directly into the line, causing total blockages in some cases. You might notice low water pressure, slow draining of plumbing fixtures, or no change at all…this last possibility is the most terrifying because you won’t even know about the problem until it becomes severe.
If tree roots pierce your water main, you’ll not only be wasting tons of water, but you’ll also be saturating the ground around your home. If you have clay soil on your property like most of America, it will expand and put undue pressure on your foundation. You may be looking at inwardly bowing basement walls or large structural cracks as a result…not to mention a high risk of leaking, flooding, and interior moisture problems that cause mold growth.
A property I did work on years ago had a cracked water main from an infiltrating tree root. The lawn was soggy and squishy most of the time, so the homeowner thought they had an issue with drainage. He paid about $10,000 for a basement waterproofing system only to find out that the problem wasn’t with drainage but with his water main.
On top of the probably unnecessary $10,000 waterproofing equipment, he paid another $5,500 to dig up the water main and repair the line. I don’t even want to think about what would have happened if that amount of water had caused the soil to expand enough to cause structural damage. Luckily for him, the break was far enough away from his foundation.
You’re still at risk of severe damage even if tree roots don’t penetrate the underground pipes and instead grow around them. Just like how roots can shift your foundation wall inward, they can force sewer lines to bow. You might get low spots in the line, called sewer line bellies, which can accumulate debris and eventually cause massive clogs in your system.
Most homeowners on public sewers think they’ll never experience sewage backup like those on septic systems. Well, think again! A total blockage in your sewer main from a tree root issue can cause sewage to back up directly into your home…talk about unpleasant.
Damaged plumbing and sewer lines underground are challenging to reach and assess. One of my past clients told me that a series of tree roots infiltrated her sewer line and water main, causing blockages in both. She paid around $7,500 for camera inspections of the lines, excavation, root removal, and line replacement.
How To Spot Tree Root Issues Before They Become Severe (4 Tips)
So, it’s clear that you should avoid hidden tree root problems as best as you can, right? But how? After all, they’re hidden…
There are a few things you can look out for that will help you identify root problems before they do too much damage to your house.
Proximity to Your Home
First, you should be wary of any trees that are near your home. There’s no set distance that means your structure is safe because species grow roots differently. However, a good rule of thumb is that a tree’s root system is an issue for your home if it’s within half of the tree’s canopy width. That means a tree with a 50-foot canopy could cause problems for you if it’s within 25 feet of your house.
The closer and larger the tree, the more likely you are to experience roots pushing through your foundation, causing moisture problems for your concrete, and interfering with the plumbing.
Maybe you have a tree near your house but haven’t experienced any associated damages. Lucky you! Keep an eye on the branches, though. If you start to see signs of tree death, including dead branches, it could mean the roots will begin rotting, which might leave you with dangerous voids under or around your foundation.
If you start smelling musty odors in your basement or crawlspace, feel dampness in the air, or see visible mold growth when you enter the space, it could be a sign of tree root problems.
Roots might have pierced a plumbing line that could be leaking water into the surrounding soil, which is then making its way inside your home. You might also have roots putting excess pressure on the foundation and causing cracks, which open up your under-home area to moisture accumulation and mold growth.
If you have a dead or dying tree near your home, you might notice insects in or around your basement or crawlspace. Some homeowners find carpenter ants or termites under their homes, while others find decaying beams or studs as a result of pest infestation. A dead tree near your house could predict a termite problem and should be removed immediately.
Are Roots From a Stump a Problem?
Most guides online will advise that the most severe damage from a tree occurs above breast height — think falling limbs and toppling trees. As such, homeowners are led to believe that cutting down a tree and leaving the stump behind will keep their house safe from damage.
In reality, this isn’t even close to being true!
Believe it or not, roots from stumps can still grow, and even if they don’t, they can still put your home at risk when they inevitably decay. You can be left with large voids under or around your foundation once the wood rots away. If the roots from the stump were large enough, the voids they leave behind could leave your foundation without support, causing structural damage.
If the stump isn’t close enough to your house to be an issue for your foundation, the roots might still be inside your plumbing or sewer lines. Cutting down a tree won’t remove those roots, and you could still have water pressure problems, sewage backup, slow-draining plumbing fixtures, and cracked or sagging pipes that need excavation and repair.
Finally, the stump and the roots will most likely die and begin decaying once you take down the tree above. Now you’re left with rotting wood that attracts pests like termites and carpenter ants. Stump roots can promote problems with insect infestation and property damage from wood-destroying insects.
Unfortunately, roots from stumps can be just as dangerous as those from a healthy tree!
Top Trees That Cause Home Damage
Any tree planted close enough to your house will likely be an issue at some point. Whether the tree roots cause foundation damage, moisture problems, or crack your plumbing and sewer lines depends mainly on the tree species.
Some of the most damaging species include white ash, poplar, weeping willow, silver maple, American elm, and any oak varieties.
White ash, poplar, oak, and willow trees are all notorious for causing foundation damage. They have rapidly-growing, strong root systems that can push your foundation wall inward to the point of cracking. The sprawling root systems of these species also commonly create issues for underground plumbing lines.
Silver maple and elm trees have shallower roots that soak up the water in the top layer of soil, often leaving the soil around your foundation dry. They’re more likely to cause moisture fluctuations that can lead to foundation cracking and structural instability.
The roots of all of these species are dangerous, and their canopies can also drop limbs, branches, and other tree debris that can damage your roof, siding, and windows and clog your gutters. Falling limbs can often be caused by root problems, including soil compaction and root rot. When roots fail to get enough water and nutrients from the ground, the tree above suffers and becomes more of a problem for your home and personal property.
What Does Tree Root Damage Cost?
Tree root damage varies quite a bit, so it’s challenging to say what it will cost you.
If you have roots growing into or through your foundation, you could be looking at several thousand dollars in repairs. You might need wall anchors installed to pull your basement wall back to its original position — these average between $3,000 and $5,000. If you just have a crack from nearby root growth, you might pay as little as $300 to have it sealed to prevent water intrusion…although you’ll then need to deal with the root to prevent further damage.
If your foundation is suffering from damage due to soil moisture fluctuations, you’ll have to remove the roots and then likely need stabilization measures. These include wall anchors (averaging around $4,000), carbon fiber support strips (averaging $2,500), or more severe stabilization, which can cost up to $15,000 or more.
If tree roots have pushed your slab upward and left you with large, sprawling cracks across the surface of the concrete, you’ll likely need large-scale excavation and installation of support piers. Depending on the type you need, you could be looking at repair costs between $5,000 and $25,000.
Termite damage resulting from dead roots or stumps near your home can vary greatly. If you catch the problem early enough, you might pay $150 to have the stump removed and a few hundred dollars to have a pest company deal with the termites. If the termite problem goes unnoticed for a while, you could be facing repair costs well into the tens of thousands. Neglect termite problems long enough, and you may need to knock down and rebuild your home!
Finally, plumbing problems caused by tree roots tend to cost at least a few thousand dollars. A cracked water main or plumbing blockage caused by tree roots will average around $1,000 to replace, but any resulting foundation damage from the saturated soil could bring that number up to approximately $20,000.
If your sewer line gets damaged by tree roots, you might pay around $3,000 on average to have the clogged section replaced. Foundation damage is possible from a sewer main crack, so you might need to tack on foundation repair costs as well.
What Does It Cost to Remove a Problematic Tree?
The cost to remove a tree that is threatening your home with its root system pales in comparison to the cost of fixing the damage it might cause. The total will vary depending on the area and the size of the tree.
You can reasonably expect your tree removal to cost:
- Around $150-300 for trees under 10 feet tall
- Around $500-800 for trees around 30 feet tall
- Around $750-1,200 for trees around 50 feet tall
- Around $1,250-2,000+ for trees 60 feet tall or more
In addition to tree removal costs, you should add on an additional $150-300 for stump removal and $150-500 to take out a problematic root system.