So the wall was installed about fifteen years ago replacing one poorly made of nasty railroad ties. As you can see it's bulging out in places (note the gaps to the post used for reference) and actually collapsed at the far end a month ago during the night. We live on sloped property. The wall sits about ten feet from the back of the house. Do I need to take this down a few levels stone by stone and reset it all? Not much room for equipment to get in here either. Not looking forward to this. We just opened a retail business before this whole pandemic thing began and are almost at our financial and mental limits. Thoughts?
Loose stacked stone doesn't work well as a retaining wall for soil/dirt. Two or three feet of dirt has a lot of side load, especially after a heavy rain.
For any chance of success they would need to be stacked so that they "lean" into the load.
You could hide mortar on the inside edges so that it isn't visible on the home side, to still have that dry stack look.
I usually put up a robust retaining wall, then hide it with the stacked stone.
Had something like that happening at my grandparents house. There isnt a low labor fix that I could determine.
Rebuild as it was an get another set of years out of it before another rebuild, or do heavy reinforcement behind it and get longer. You will have to tear down and redo though. It sucks.
Most of it looks to be in pretty good shape. Maybe focus on the problem areas, mitigate water or other issues that contributed to the collapse, and get another 15 years out of it?
Had a similar situation and went with interlocking blocks without a foundation. Still holding up solid after 15 years when we sold the house.
In reply to jfryjfry (Forum Supporter) :
Hey! I was just reading about you in a particular magazine... 
In reply to vwcorvette (Forum Supporter) :
That's exactly what I'm doing as we speak . Yes take it down all the way and reset the bottom stone tilted slightly in towards the wall leave about 2-4 inches open behind the stones for rock. Sized 3/4 plus. Do not use pea gravel. The rock relieves water pressure and moves around slightly like springs on a car during frost heaves. the Rock will add years to the wall.
Careful to brick stack the stone. That means the piece on top should span the gap between rocks. Try to keep the same thickness stone in a row. Set back each row of stones roughly 1/4 of an inch or so.
For the record mine lasted 15 years too before falling. Down about a month ago.
At my age it takes a long time to do. I originally built that wall in a day and a half but failed to use the stone behind. Except at the very end and top. Which is the part that didn't fall.
I called landscapers and masons. They all want to turn it into a $20,000+ project. It will take me a few more weeks but cost me only $200 for the rock.
Drainage rocks behind the wall and weep holes in the wall will relieve the hydraulic pressure which blows out the wall. You can see weep holes in well built walls they're the drainage pipes down near the base.
Things totally depend on what's behind the wall, and I'm not talking about drainage.
This was my retaining wall in my old house:
It wasn't very tall, and it didn't have that much of a slope behind it. It was backed with about 6" of 2B limestone gravel, and had crossed rebar achnoring it as far as 8' uphill. It lasted 3 years. That uphill behind it isn't steep, but it continues uphill for another half mile. My little retaining wall was more or less trying to hold a mountain that was full of little springs that were constantly and slowly moving the dirt downhill. No amount of drainage was going to save it.
A retaining wall should be called a "slowing" wall. It doesn't retain anything. If it is properly engineered, it will last a longer time than a poorly engineered one, but they are like trying to stop a bulldozer with a baloon. Build the right balloon, and it will slow down the dozer for a while, but it will inevitably give way to the pressures of the earth it is holding.
For the record, though, the retaining wall outlasted the Dakota by 2.75 years. GOD, I hated that thing.
To be clear, the wall was done by professionals 15 years ago. The top foot was added two years ago.
I was hoping someone would come up with a way of pushing it back, but that's a dream that ain't happening.
Curtis, I like your response and agree it's only a matter of time. We live in a heavily sloped yard with ledge and clay like dirt. Drainage has always been a concern. There's a French drain about 25 feet up the hill to direct water around the wall and the back of the house.
You can just about make out the swale that is the drain in the distance in front of the apple tree and steps to the upper patio.
Looks like this will be me soon.
Way to far to come and help but good luck and don't over do yourself.
In reply to vwcorvette (Forum Supporter) :
Here's a not cheap solution. During a period of a week or more you expect to be dry have someone with a mini excavator( back hoe) dig a trench behind the wall, go down 1.5 times the wall height. Gently, Use the blade on the mini excavator to push back any stone out of place.
Put a few pvc tubes going to daylight or gaps between stones at various heights. And every few feet. The goal is to drain water through the concrete.
Now split half of the width of trench with a plywood form the whole length of the trench. You can use cheap 1/4" plywood or luan ( (Drilling holes for the PVC to stick through). since as you'll pour concrete on one side as you'll dump river rock on the other side backing the plywood up. Using river rock as you pour concrete will save you the expense of heavy forms that have to be removed. Stop about 3-4 inches below the of the top of the wall.
Once the concert hardens (Or gets stiff ) you can put top soil on the remaining 3-4 inches and let grass grow.
The PVC will let water pressure seep through the stone bypass the concrete and weep onto the driveway. Keeping hydraulic pressure and freeze pressure off the wall.
Pouring concrete against plywood backed up by loose stones will take coordination and technique you might find a few stakes down at the bottom help. Both things have to happen at once. Concrete and stones. One pushing against the other.
There needs to be a French drain behind the wall. The pressure from wet soil is significant. Freeze thaw too if you are in a cold climate.
Dig a trench behind the wall, 8-12” wide. line with landscape fabric, install perforated pipe that drains to daylight on one end (or both) or a couple spots through the wall. Fill with clean 57 stone.
Get the water out and the wall will be stable.
My neighbor just completed a wall like Frenchyd's. As he went up, he laid some kind of rebar about 4 ft. long perpendicular to the wall into the bank behind it. Every 4 ft. on the wall and every third or fourth row, fill in dirt to bury the bar. I can see how that would keep it from getting pushed over.
Free standing wall? I have no idea, but something to think about.
Not exactly finished but close enough. It's the same height as original and remarkably the wall lasted 15 years. The part that washed out was at the 4 foot point not the highest point which was about 6 feet.
You can see the stone behind. That will be covered with ground cloth and then about 3-4 inches of dirt added on top.
The effect will be excess rain water will flow over the wall and down towards the lake . The real force of crumbling a retaining wall, freezing ground, will be dealt with the river rock acting like a spring and shock absorber.
