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Over zealous Grading - I Should have known better

Posted by lynn_8989 7 (My Page) on
Sat, Mar 24, 12 at 9:25

Our back yard was all woods - no grass - just trees and scrub and overgrown ivy. We bought the house three years ago and removed much of the ivy. Most of the rear yard is sloping toward the far eastern corner where it fenced and just outside the fence, the lot, like all of our adjacent neighbors, turns into a much steeper slope down to a lake. The area outside the fence has never been touched - all woods - and we intend to keep it that way. The west side of the rear yard is a gradual slope and never been a problem. The east side of our rear yard had a pretty steep slope that ran beside the house that was washing away into a deep gully and my concern was that it would continue to wash closer and closer to the house foundation. In addition, we had a 38'x 14' brick paver patio (set in sand) below the same size deck, supported by an unmortored 3' retaining wall on that same eastern sloping side of the house and rainwater has washed out the dirt support for this side of the patio and caused it to sink. My husband thinks rain coming through the deck did most of this damage so we plan to install under decking to keep it dry and more usable. When we pulled the pavers off and looked at the support underneath them and the retaining wall we found the wall had no rebar, no concrete footings, etc. I'm a professional commercial landlord with lots of experience and good contacts, so after discussing this with my building and grading contractors (who are not landscapers - AAGH - big mistake) we thought the logical fix was to rework the slope, redo the retaining wall properly and repack the patio area with more dirt and crusher run and then pour a concrete patio that will be stained. The grader came over and moved dirt around to pack dirt back around the house, built dirt up on the offending side of the house, buried new downspout pipe, etc. It still has a steep slope but its further from the house now. He also removed the rest of the ivy, which in hindsight was probably a mistake on that side of the house but it has invaded everywhere, including my neighbor's yard.
We repacked the dirt for the patio with new dirt and crusher run, put in rebar, poured footings and redid the retaining wall and I'm happy with that work. We'll install the concrete patio sometime soon. I still have to work out the area just outside this lower patio area and the steps leading down to THE PROBLEM.

Here's the problem: The grader called me while I was at work and asked me "While I have the bobcat out here, do you want me to grade that firepit patio you've been talking about?" Since I have 500 sf of brick pavers from the below deck patio, I thought we could reuse them there. So, I guess he gave me what I asked for. I told him in general where I wanted it bc there was already a clearing in the middle where we had removed some dead trees. I just didn't realize he was going to make it so big - its 20' in diameter and what really worries me is the way he bit into the dirt on one side that supports two large trees. I knew that any lower patio would require a retaining wall, but I didn't plan on having to build one 40' long and 36" to 42" tall! My husband wants to put in a waterfall at the tallest part of the retaining wall which will look great. This is where a landscaping plan would have been the best idea so I stopped all the work for this firepit patio to rethink and get advice on what to do. We covered the dirt wall with plastic while I rethink this. I've attached photos so you can see. My gut tells me that I should reduce the size of this patio and put some of that dirt back to avoid hurting those two trees (plus reducing the height of the retaining wall), but my husband likes it. I think it looks a bit like a bowl. I don't mind hiring a landscaper to give me an opinion and draw up a plan for the back yard, but I'd like this forum's opinions first. If someone can tell me how to directly insert the photos here? I tried to find out from the site, but it just kept directing me to link to photos on a website. Copy and paste isn't working.


Follow-Up Postings:

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RE: Over zealous Grading - I Should have known better

You have to upload your photo to a photo sharing site. I use photobucket. Then you can put your photos here via the sharing site. Do not use the IMG link.. Use the HTML link

You can not upload directly from your computer or camera to this site.

You don't have to use photo bucket.. there are lots of other image sharing sites out there.

Here is a link that might be useful: photobucket


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RE: Over zealous Grading - I Should have known better

upload the photos first to a photo-hosting website (flickr, picasa, imageshack or the like.) Once uploaded, you'll be able to obtain the HTML CODE for each picture. Finding this code usually involves starting with the "share" link that is somewhere on the page with each picture. Explore to find this. There may be several codes available, so don't get the one for thumbnail size pictures, or other odd things. You'll copy the code and paste it directly into the message you compose here. It will show up when you preview. If it doesn't, go back and explore more, looking for the correct code.


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RE: Over zealous Grading - I Should have known better

OK, Let's try these photos:

The first two show the size of the bank for the retaining wall. The last one shows how close the wall is to one of the large trees.

Retaining wall area for firepit

View of Firepit from above

Close up of tree at retaining wall are


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RE: retaining wall blocks

I went to a stone yard yesterday and this is what they recommended: use segmental retaining wall blocks (Belgarde or Pavestone were the two they had), make the trench a foot deep and 18' wide, put gravel in the bottom, put the blocks on top and fill in most of the openings in the blocks with gravel and also put gravel three inches wide behind the blocks. They said if I have to go higher than 42 inches (I'm hoping not to) I should also use this webbing product that goes in between the blocks back into the dirt. They do not fill any blocks with concrete bc these blocks are designed to move a little. The least expensive blocks are 8" and about $5 each with my professional discount. I like the look of the 6 inch much better, may spring for the extra cost. I posted the pics here again to make it easier to see this proposed wall. I would love your opinions please.

View of Firepit from above

retaining wall area for firepit patio


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RE: Over zealous Grading - I Should have known better

WOW..That's a lot of work!
I'm so glad you figured out the picture posting.
Sorry to say I can't advise you on the retaining walls or how they might affect the trees.

I do think its going to be gorgeous when your done with it though.


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RE: Over zealous Grading - I Should have known better

Some of your photos are a little too close-up which makes it hard to grasp the context. What's certain is that the excavation needs to be somewhat larger than the finished product and then backfilled. I wouldn't label this overzealous grading. It requires a little extra room to perform the construction. So you see the maximum extent of space you have to build a patio. But there's nothing to stop you from shrinking it if you desire. However, thinking that putting dirt back around a tree is somehow equivalent to putting roots back is just not accurate. An amputation cannot be undone. Putting dirt back will make no difference. In spite of that, the tree will re-grow some roots as that's what they do. The ultimate patio size is a factor of desire and space available, but as patios go, it certainly doesn't look too large. Neither does it look like the ret. wall will be abnormally tall. Its curved shape will add strength. It will be stepping or sloped down in some way to generally follow the earth so it's highest section will not extend for great width. Its height is a balancing act between the patio elevation and the surrounding soil levels. Calculate these out and adjust them as you see fit. Raise the patio too much and you will be filling the bottom end or shrinking the patio size. Lower it and you'll be creating a taller retaining wall. Balance and moderation are the key. As I look at the pictures, I don't see anything that can't be worked out to a decent conclusion... if the right design decisions are made along the way.

If this were my yard, I'd prefer the appearance of a nicely detailed mortared stone wall, but that requires more skill and higher cost material than the kind of block you're proposing. Therefore, it would be more expensive. But it would look better, too. What you decide on is a factor of cost vs. benefits as you see it.

At the end of it all, it will be imperative that you establish groundcover capable of holding soil in place. This is a key to preventing erosion.


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RE: Over zealous Grading - I Should have known better

Those trees are done for.


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RE: Over zealous Grading - I Should have known better

I don't know where you live but since your property is beside a lake, is there a chance that, under the top layer of so-called dirt, the tree roots are actually anchored within the bedrock not too far below? That was my own experience but then, it was in the Canadian shield.

After clearing immediately around the cabin (for reasons of high wind and fire safety), we felled trees selected for poor health or bad sightlines. Fortuitously, we discovered that the tree roots were deeply embedded in limestone crevasses. And furthermore, by removing about a foot of soil, leaf litter and scrub, natural stone patios were unearthed. It was a heck of a lot of work to do without machinery but easy enough in the long run. I planted thyme and creeping phlox between the cracks to protect unguarded ankles or colourful flowers beds in larger pockets. For my "real" garden though, it was necessary to create a raised bed.

The photos in this album show the mostly intact remaining woodland ravine leading obliquely down to the lake and the natural ledges. Good luck to you.

Here is a link that might be useful: Natural patios in a woodland setting


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RE: Over zealous Grading - I Should have known better

Thanks for calming me down on the size of this patio. I think I was just shocked. One of the two affected trees didn't have any roots chopped so I think I'm ok there. It's difficult to tell with the other one since the grader removed two very large stumps right next to it that had tons of roots coming through the excavated area. I'll just hope it survives the chaos.


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RE: Over zealous Grading - I Should have known better

  • Posted by bahia SF Bay Area (My Page) on
    Tue, Mar 27, 12 at 19:47

As already stated by others, the size and height of any walls and patio layout are easily manipulated within your rough grade. The bigger issue is whether the trees so close to these grading cuts haven't been compromised by loss of structural roots or feeder roots that will cause them to fall or fail over time. I'd suggest you get an arborist to look at them carefully to determine if they are safe to retain, or have been too badly compromised to leave standing.


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RE: Over zealous Grading - I Should have known better

That's a good idea. Will post results when I find out.


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RE: Over zealous Grading - I Should have known better

Trees grow roots very fast. If you go through one growing season without high winds, I think your trees will be okay. When we did our drainage project we cut roots of one big tree from 3 sides. When heat arrived, it lost almost all leaves, but we kept watering it regularly and next year it came back fine and now looks very good. I still watch it closely and water if we have hot, no rain weather for too long.


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RE: Over zealous Grading - I Should have known better

  • Posted by bahia SF Bay Area (My Page) on
    Wed, Mar 28, 12 at 15:22

Major structural tree roots getting cut won't be able to regenerate quickly, if at all. If a tree has had major root loss on 3 sides, and is in a location where it could do major damage if it fell, it might happen decades later. It is always best to avoid cutting major roots and minimizing grade changes within the tree canopy if possible. The situation with your patio grading definitely gives reason for looking more closely with a professional's review.


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RE: Over zealous Grading - I Should have known better

How would an arborist know if this oak was damaged?

Fortunately, there is just one tree at risk since the other was closer to grade level and didn't have any roots showing. I do need to get the excess dirt away from it, which I'll do tomorrow. Regarding the other oak, there were lots of very thin roots showing through the bank, most of which were less than an inch around. There may have been some larger roots cut that I didn't see, but it was hard to tell which of these roots were from the live oak because we had felled two large pines right beside it and the grader was removing their stumps. In hindsight, we should have just stopped grading about four feet further in and there would have been no tree issues at all. That's what I get for not being there watching every minute, I guess. Paving tomorrow, sure hope that goes more smoothly....


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RE: Over zealous Grading - I Should have known better

  • Posted by bahia SF Bay Area (My Page) on
    Thu, Mar 29, 12 at 11:57

Removing the excess dirt and materials so that you can see the amoun and size of roots cut is a good first step. Any arborist called out to consult would need to be able tower the extent of roots cut to evaluate. You might also try following main structural roots out from the base of the trunk to help identify direction and size of main roots. You may be fortunate that your oaks don't have a lot of structural roots cut; but if it were my house, I'd want some professional opinions on the issue. Hope it turns out well.

Grading around trees and major pruning of trees are two types of work that are always best done with the owner or landscape architect/designer on-site to direct/review the work as it proceeds, too many things can go wrong or need the owner's input for best results, and the graders/tree pruners aren't mind readers.


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