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Need advice: concrete patio too close to a large tree

JTM

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Dec 7, 2011
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804
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North Alabama
Most of the holes are there because the edge of the patio is on a very steep hill, and there was concern there wasn’t enough load-bearing soil there. So, a small retaining wall was built along the
to fix that, and these holes were also dug as an additional measure - I assume so that to more of the weight of the concrete slab would be away from the edge of the hill.

Interestingly, we got estimates from a lot of contractors (some big expensive companies and some smaller shops), and pretty much all had the same approach for the hill / slope (retaining wall + holes).

And...not a single one mentioned anything about not being able to get close to the tree. Perhaps one of the others would have brought that up during the actual project (obviously the company we chose didn’t), but none brought it up during the estimate phase.
Roger that on the holes. Never a shortage of nearsightedness in construction trades.
 
phil2006

phil2006

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Roger that on the holes. Never a shortage of nearsightedness in construction trades.
True. Although, I don’t know if it was nearsightedness or if he genuinely didn’t know. He did a great job otherwise and helped us with some smaller side projects and went above and beyond in many ways, and is now coming back out to cut away the 7’ radius around the tree at no charge. So, maybe he didn’t know or maybe an oversight, who knows.

If I were to do another stamped concrete project I wouldn’t hesitate to work with him again. Although, knowing what I know now, I would probably rewind to October when we chose to use stamped concrete for the patio rather than pavers and choose pavers instead, as I understand they’d be better for the tree. You live and you learn.

I’ve got an arborist scheduled to come out later today and will update again afterwards. Appreciate everyone that’s taken the time out of their day to come on here and post something to help us out, it’s much appreciated.
 

JTM

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Dec 7, 2011
Messages
804
Location
North Alabama
True. Although, I don’t know if it was nearsightedness or if he genuinely didn’t know. He did a great job otherwise and helped us with some smaller side projects and went above and beyond in many ways, and is now coming back out to cut away the 7’ radius around the tree at no charge. So, maybe he didn’t know or maybe an oversight, who knows.

If I were to do another stamped concrete project I wouldn’t hesitate to work with him again. Although, knowing what I know now, I would probably rewind to October when we chose to use stamped concrete for the patio rather than pavers and choose pavers instead, as I understand they’d be better for the tree. You live and you learn.

I’ve got an arborist scheduled to come out later today and will update again afterwards. Appreciate everyone that’s taken the time out of their day to come on here and post something to help us out, it’s much appreciated.
And that makes a huge difference, having folks work with you and learning. I just had a porch poured as well. Told the guy the dimensions. He laid it out and showed up the next morning just before I was leaving to dig and pour the footer. I walked around the area with him and realized that the water supply line entered the house right under where the footer was to be dug. Just moved that side over a couple of feet and all was good.
 
phil2006

phil2006

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So the arborist came out today, and what he told me actually surprised me a bit. Not sure how many schools of thought there are around these sort of things but certainly more than one it seems.

I’ve summarized the main points below, would love to hear from anyone knowledgeable out there that might have a different view or confirm what he told me:

1) while the situation isn’t great, he would be much more concerned if it was any tree other than a white oak. He says white oaks have roots that grow extremely deep vs other trees where the roots spread out more horizontally, and at that depth there is plenty of moisture for the roots to draw from regardless of what’s happening at the surface. He said white oaks are often the tree of choice when planners want large trees that can do well near concrete / paved surfaces. He also said the age of the tree would help also (ie that the trees roots have long been established). Is this all accurate?

2) when I asked if removing the concrete within a 7’ radius of the tree was enough, he said the tree would probably be fine either way but yes that would be better than doing nothing.

3) when I asked whether replacing the 4” of concrete patio with landscaping fabric + 2” of mulch + 2” of gravel would be okay, he basically said anything would be fine even bricks or pavers. Any thoughts on this?

4) I asked about nutrient injections or fertilizer that I could use once the concrete is removed, and he suggested using this in early spring. Any thoughts or experience with this product? https://drjimz.com/products/tree-fertilizer-tree-secret-save-a-dying-tree

again, this all surprised me a little so if anyone has any thoughts they could share on any or all of the 4 items above I would very much appreciate it. Thanks.
 
Raintree

Raintree

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1) It's not about species, it's about the tree's age (vigor) and the damage to the root system. Deep roots help stabilize, shallow roots feed (health). Tree of choice when "planting" new. Established roots outside the construction zone are to be fertilized, not the buttress roots near the trunk.
2) Removing concrete from the stump area is for expansion of the root flare not for water and or nutrients. No feeder roots by the trunk, they got dug out. 7' is excessive, backfill with sand or gravel.
3) Have the tree professionally fertilized, deep root injection.
 
phil2006

phil2006

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1) It's not about species, it's about the tree's age (vigor) and the damage to the root system. Deep roots help stabilize, shallow roots feed (health). Tree of choice when "planting" new. Established roots outside the construction zone are to be fertilized, not the buttress roots near the trunk.
2) Removing concrete from the stump area is for expansion of the root flare not for water and or nutrients. No feeder roots by the trunk, they got dug out. 7' is excessive, backfill with sand or gravel.
3) Have the tree professionally fertilized, deep root injection.
Thanks for your response and for helping us out, sincerely appreciate it. It seems you have a different view than the arborist that was here today, which I appreciate. A few of the things you said I didn’t quite understand...mind if I ask you a few questions to clarify?

1) you said “Removing concrete from the stump area is for expansion of the root flare not for water and or nutrients. No feeder roots by the trunk, they got dug out.” I don’t think any roots actually were dug out. In fact, we created a step up to create the patio, so all we did was add soil near the trunk and compact it, but didn’t cut any roots there. Does that change your response at all?

2) considering that those roots were not dug out, do you still consider removing the concrete within a 7’ radius to be excessive? If so, how many feet would you suggest? My goal is to allow for water / nutrients, but if removing concrete near the trunk won’t accomplish that, then maybe I need to rethink removing that concrete. If what your saying is that the concrete near the trunk isn't hurting the tree (assuming I'm understanding that correctly), then maybe it doesn't make sense to remove it after all.

3) I will have it professionally fertilized as you suggested. I assume this would this also be done by an arborist? I guess I just need to contact a different arborist then, because the one that came by today didn’t seem to think that was necessary. But I would rather take your advice and be safe rather than sorry.

4) you said “Established roots outside the construction zone are to be fertilized, not the buttress roots near the trunk”. None of this tree's roots are visible (nor were they before the patio project), so how do I go about doing this? Or is this something that a professional would need to do? The arborist that came out today didn’t mention this, only suggested that DIY product which is applied near the trunk.

Thanks so much for your help
 
Raintree

Raintree

Penguins are tasty
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Messages
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Figure-1.jpg

This drawing may help you understand the tree root system and where to fertilize. Anchor roots are buttress roots.
I would recommend removing about 2-3ft of concrete around the trunk. Dig out the construction fill to the original grade exposing the trunk flare. Leaving the well open if you can, if this hole is a hazard backfill with gravel.
The tree's survival has increased knowing the patio area was not excavated and no transport roots cut. However, you have lost important feeder roots under the new patio. Fertility and water management is crucial over the next few years.
 
phil2006

phil2006

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Joined
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Messages
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Virginia
Figure-1.jpg

This drawing may help you understand the tree root system and where to fertilize. Anchor roots are buttress roots.
I would recommend removing about 2-3ft of concrete around the trunk. Dig out the construction fill to the original grade exposing the trunk flare. Leaving the well open if you can, if this hole is a hazard backfill with gravel.
The tree's survival has increased knowing the patio area was not excavated and no transport roots cut. However, you have lost important feeder roots under the new patio. Fertility and water management is crucial over the next few years.
This is extremely helpful, thanks for taking the time. I’ll do as you suggested and have it professionally fertilized as well. Appreciate all the help!
 
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