Rebuilding a retaining wall

[John Fitzgerald]

I have an old rock faced masonry retaining wall that holds back about four feet of dirt. It is leaning, and will soon have to be replaced. About 36 feet long. Does anyone on here have experience with the prefab dry stack blocks that lock together like Legos? Or something similar. I don't want to have to hire a contractor to do a concrete wall, if I can help it. This holds back dirt from the edge of my driveway for a small distance.

 

[marchanna]

Key thing is a good base. Secondly, the thickness of the wall should be appropriate to the amount and type of soil it’s holding back.

I’ve put a few in over the years.

 

[jfh28]

check the manufacturers instructions for installation and limitations of their product and then match it to your specific situation........an important thing for a retaining wall is drainage.....wet dirt weighs a lot and a high clay content can be problematic so follow their recommendations......in general once you have a solid level base the blocks themselves are not difficult to work with........Jack

 

[davrow]

Can you be more specific on the types of blocks you mean? Concrete lego blocks I'm familiar with weigh 2,000-5,000 lbs. Do you mean normal retaining wall blocks with a lip? Or some other kind of block.
I agree with John... proper foundation is key to stability and long life for the wall.
4 ft is about the max for a non-reinforced retaining block wall, lower if there will be pressure behind it (like driving tractor on the terrace it can form).

 

[flingwing1969]

You will want to ensure that the hillside the wall is holding back drains well. Often, a wall is fine for holding the dirt back but can't take the hydro-static pressure when the soil behind the wall gets saturated. Also, I like these blocks for a natural look, good drainage, and easy build. I got a great buy on a lot of them that were bought and never used before the buyer died. They are not inexpensive but they really do the job and become part of the landscape as opposed to hardscape - if you want that look.

Why Living Retaining Walls? - YouTube

 

[Streetcar]

Drainage is very important for long lasting wall. The precast blocks require a level compacted base

 

[RNeumann]

Proper footing/base as mentioned above. Some of the nicer and or higher rated walls have a fabric/grid mesh that ties back into the hill. Chevron has a station near us that has a dry stack type wall that has to be 20’ high and has a building on 100% fill.
The other two keys are to export 3-4’ behind the wall and bring in good crushed stone/engineered fill. The other key that goes along with that is to add landscape fabric and a 4” perf drain to prevent any hydraulic pressure on the wall.


Your local brick maker will have the options for you. Bricks don’t ship too far so trying to find a specific brand or look is a waste of time. Your local yard’s choices is the only practical options.

 

[Redlands Okie]

Good base and proper drainage with material to protect the drainage from clogging up.
The actual blocks and wall its self is almost a minor part of the job for a long term productive wall.

 

[John Fitzgerald]

The old wall has been there about 50 years, and I think it started failing when the former owner replaced the sewer line about 25 years ago and had a back hoe working only a few feet from the wall. The sewer line is deep and goes under the far end of the wall. I have had the place four years, and the wall has leaned about two inches more since then. It's along one side of the approach to my walkout garage-basement. The dirt level is from 8 to 12 inches below the top of the wall. The part within ten feet of the concrete garage wall is thicker and barely leaning at all. The new wall will need to be 48-50 inches tall. The old one is 58". Here's a picture.

 

[DrRod]

You need to get a copy of Stone Work by John Jerome. It is the month by month thoughts of a guy rebuilding a stone wall in New England. I'm sure you will find that it speaks to you as you undertake this project.