Shoring up a retaining wall between upper/lower lots

Manch, can we get a “Home improvement” category?

Talked to one of our neighbors, and they have concerns that parking along their property is damaging their retaining wall. I’m guessing it’s a 5-6’ retaining wall, and the edge of the car is about 4-7’ from the retaining wall depending on where on the pavement you park. They apparently replaced the wall a couple of years ago and think it’s already budged a bit since then.

What can be done to shore up the parking spot and rectify the problem permanently? Can you drill down to rock and put in supports?

Also, does planting trees along that wall help or hurt the stability? I’m assuming that the row of trees was planted to try to stabilize the wall, but concerned that in 20 years after they’ve grown a bit, they could start leaning towards the neighbors property and become a problem. Trees are currently 5-6’-small enough to remove.

I have a feeling that once a retaining wall is compromised (leaning or worse) at the footing you essentially want to just redo it fresh as opposed to trying to fix it. Maybe it was made without rebar reinforcement or drainage rocks, which may be why it is in the state it is today.

Sure. I don’t think it’s that bad right now. Just they replaced it, and top corner is moving again? I don’t know, but I’ll get to see it in person in a week or two.

But they already redid the whole thing once probably in the last 10 years. I think the issue is that the dirt under the parking spot needs to be shored up which would take the pressure off the retaining wall so it’s just holding up a bit of dirt, not a bit of dirt plus a car…

What may be needed is a good drainage system underneath. I just did a major walkway project at the SB house where underground drainage from the backyard and then downspouts from the fairly large roof would get all the way out to the front sidewalk gutter. The old adage about keeping water away from your foundation and home is really true.

Water is the big(est) problem if retaining walls. Drainage done? Is it functional?
Elt with engineering expierence may give you bettere idea what and where and who

Drainage was done recently and more might need to be done, but I think there’s still a reasonable concern over the weight of a car packing down the soil…especially if it recently rained.

@elt1 @ptiemann Thoughts?

how was drainage done recently? It’s installed when the wall is built.

Most retaining walls fail due to inadequate piles. Rule of thumb. The soldier beams should be drilled twice as deep as the wall. 3’ Wall should have piles 6’ deep 6’ on center. 6x6 post
5’ Wall should be 6x10 posts 10’ deep 16” diameter holes filled with concrete
6’ and above use concrete or steel and maybe a double row of staggered piers.

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The wall is on a different property. Drainage on the property above the wall was in 2013.

Can i shore up the parking spot and driveway near their property/retaining wall with posts and piles and call it a day? I figure that’s the best I can do on my end. (And is there a guess as to the price tag on that?)

I’m back.

The neighbor is complaining about us parking over his retaining wall again. He says that there is a stress fracture in the middle of the wall, though I wasn’t able to go to his property to see it. He claims that the wall was built correctly and “passed building inspections.”

It sounds like there is a lot of run off through my property from a “creek” which no one can really see, but runs underground. This has been told to me by 2-3 people, not just this neighbor.

I do not know what drainage the lower neighbor put in, if any. Our previous owners put in a system that captures the water that runs from left to right of the house, and funnels it past the front neighbor’s house. But that only captures ground level run off, not anything underneath.

What are my options at this point? I don’t see how I can divert an underground creek that could run 5 feet under my house straight into their backyard at ground level. Would putting in piers under the parking spot take all responsibility off of us? I don’t think I can fix their issue, but I feel like I could do due diligence to take pressure off the wall. I’m not convinced that they will believe that it works, but if this goes to court later, I feel like proactively covering my butt is probably a good thing.

Hi Terri,

Can you take a few pics so that we can visually see what the situation is over there?

The top is our parking spot, bottom is their property. They said that the retaining wall is 2-3 feet from the fence, but I have to assume that it’s under the fence. Either that, or that’s not a retaining wall is it?

They also said that the fence had issues leaning, but seller fixed before he sold.

Neighbor is also concerned about the trees causing further stress as the grow heavier.

Is the retaining wall really retaining anything (by definition) since on the other side is essentially your parking space? I take it you confirmed that the fence is directly on the property line?

Parking space is about 5-6 feet higher than their patio, so yes, stuff needs to be retained. The neighbor is claiming that parking the car is breaking the wall that they installed.

I haven’t verified where the property line is.

To be clear, the question isn’t who should pay for the wall. These guys are simply stressd out that they paid for a wall to be replaced, that our sellers kept parking above it, ignored their pleas, and put a bunch of soon-to-be-heavy trees in and that the wall may break again. They are high worry people. They also moved in probably 30 years ago and aren’t making current salaries.

Now that you’ve asked for this picture, I’m wondering if this whole thing is wood. I’d assumed it would be cement. If it’s wood, then yeah, no kidding the wall is going to fall apart. :frowning:

I guess I am confused or the picture is not really showing it. I guess a side picture would help to show that upper parking lot is being retained by the wall? I guess I am used to retaining walls literally holding back say dirt from a hillside or something…


The picture looks shallower than it is. There are two parts retained–the part below the fence (looks like 2 feet), and then the 3 feet that looks like a place you’d plant your veggie garden.

Tagging @manch