How to Build a Retaining Wall
Come see how to build a retaining wall. Our beautifully curved retaining wall features a top cap to make it more comfortable for sitting, steps for access to the garden, and a buried drain pipe for water runoff, plus a tip on how to keep spiders from moving in.
Finish the space with a DIY fire pit, a DIY patio table with built-in drink coolers, and some outdoor patio lights.
How to Build a Retaining Wall
using RumbleStone Rustic Building Blocks by Pavestone
We worked in partnership with Pavestone on this project. All opinions are my own. This post contains affiliate links. Read our full disclosure policy here.
Designing our small backyard for certain purposes made the yard feel bigger and made it much more usable! We strongly suggest you draw out a final plan for your yard so that you will love it as much as we love ours!
Here’s our sketch of the entire back yard plan:
In the design, the retaining wall is right in the middle, wrapping around an existing pear tree with a fire pit nearby. These are two of the main architectural elements that we will see out our kitchen window. The fire pit is laid out to be centered to the existing pear tree and the window of the house.
As we worked on the patio project, I started to do some research on how to build a retaining wall we would love.
I wanted a stone wall and I found RumbleStone outdoor building blocks by Pavestone, and it was exactly the beautiful look I was after!
A major selling point was that I would be able to build the raised garden bed to the shape of my design and have a matching fire pit to go with it. Perfect!
How to Build a Retaining Wall: Materials
The dimensions of our retaining wall are
- 48 square face feet (meaning the front of the wall that is exposed)
- 32 feet long
- 19 inches high (including the cap)
- 14″ wide
The wall has three curves and has a small set of three steps that take you up to the bigger garden area. This required:
- (5) Pallets of RumbleStone Block – Sierra Blend Color – I used a total of five different block sizes and types: three different rectangle sizes, squares, and trapezoids.
- (15) Construction Adhesive (30 oz. bottles) – For bonding the blocks together to prevent movement.
Because I was building a 19″ high wall that will double as a bench for seating and because it will hold some soil pressure on the back side, I needed to keep the water from flowing through the wall. I installed a drain pipe as well, which required:
- (30′) of 3″ Drain Pipe – Drains water away from the wall at the base.
- (1) cubic yard of Gravel – For back filling over the top of the drain pipe.
How to build a Retaining Wall: Tools
- Paver Saw – Rented from The Home Depot – $65 a day – To cut 3 1/2″ thick block.
- Large Caulking Gun – For the bigger construction adhesive bottles.
- Hand Broom – Sweeping off gravel after filling gaps.
- Floor Broom – Cleaning up the gravel.
- Wheelbarrow – Hauling the blocks to the site.
- Shovel – Moving the gravel
- Metal Straight Edge – marking lines for cutting blocks
- Wax Pencil – marking lines for cutting blocks
- Tape Measure – measuring the cuts
How to Build a Retaining Wall: Step by Step Process
1. Prep the base
When I poured the patio, I made sure that I added rebar to the concrete on the edges, to give it extra strength to hold the additional weight of the wall. This gave me the perfect flat surface to glue the block wall to.
If you are installing the wall on a different surface, follow the installation instructions from Pavestone to prep the base.
2. Drain pipe and base layer of blocks
Before I started laying the block in place I connected the drain pipe and laid it next to the concrete patio where I had cut out the soil to fit the pipe.
This is where the drain pipe starts at the house and works its way to the lawn. (Picture taken after a few layers of the wall were down, sorry!)
Then I started off with the base layer of trapezoids, squares and large rectangles.
Once I laid out the first layer, I checked that the wall shape looked good and I made sure that the radius of the curves were as true as I could (using a central point and a string to curve it out perfectly).
I chose to use all larger blocks to give the retaining wall a very solid base. I then applied a good amount of construction adhesive to each block and flipped it over in place.
(Smiley faces are not required, but were appreciated by my little girls. Also, this picture was taken a few rows into the project!)
3. Let the base cure, then get to work!
After the base was glued down and cured for a couple of days. I worked on the next layer. The entire wall took me about three weeks to do by myself.
I worked on it when I could, about 2-4 hours at a time for the most part. I was okay with that. It gave me time to get it done just the way I wanted it.
With a few layers down, you can see how I used alternating block shapes to keep the joints from lining up between each layer of block. This makes it stronger and it looks a lot better.
I also tried not to create a repeated pattern, but randomly alternated how the little blocks were placed in each layer.
4. Back-fill with gravel
When the retaining wall gets tall enough, back-fill the gravel over the drain pipe.
The stairs were a little tricky. I decided to keep the drain pipe going under the first step. I had to make sure that the slope of the pipe would remain so it would still drain water. Luckily it did and I was able to hide the pipe under the second stair with no problem.
I cut back the soil where the stairs would go up, taking out a little extra for room to work. After that I poured in a 2″ layer of gravel for the base of the block to sit on. This way I was able to level it perfectly.
I decided to try and use our trusty little tile saw to cut the top of the stairs to the right shape.
They are 1 1/2″ thick, twice as thick as my little saw could handle. In order to cut it all the way through, I had to cut one side then flip it over and cut the other side.
I had to cut the block without the guard and this is what happened. It sprayed all over me. Cassity thought that it looked SO funny and had to take a picture of it.
It took me 4 hours to get the first step blocks cut to shape. That was way too long. I went out and rented a bigger saw!
Here are some progress shots of the steps going in.
Here they are all cut and in place.
6. Continue with the layers
Using the same process as before, build on layers. Stop when you’ve reached your desired height.
Near the end of the wall, I had to make sure the front AND back of the wall looked good. Due to the slope of the flower garden area, both sides of the wall will be seen here. I like how it turned out!
7. Keep out the spiders!
Because of the curved design, there were gaps left between the trapezoid pieces. Cassity had a great idea to fill the holes with the gravel to help prevent spiders from moving in. The last thing she wanted was to sit on the nice new wall and have a spider crawl out! I actually found three black widow spiders that had moved in just after a few days of building the wall. Thanks, honey, for the great idea to keep them out!
We used a cup to transport a bit of gravel and pour it into the spaces and a hand broom to sweep the gravel into all the spaces.
At this point with five layers, I was ready for the cap pieces.
8. The top cap
A cap will cover up all the gravel holes and make a nice finished place for sitting. We decided to add a small 1″ lip to the cap for dimension. It worked out perfectly to cut a long rectangle in half for the pattern to work. This saved us from having to buy more blocks. Awesome!
Because of the curved design, I had to cut each side of the block to make it a trapezoid. This took a lot of time, but it was well worth the final look. I also hammered the cut edge to make it rough so it matched the “rustic” tumbled edges of the Pavestone blocks.
I rented a paver saw for a day and it took me the WHOLE day to cut all the cap pieces: 8 am to 9 pm! I think I got my money’s worth.
9. Corner Platforms
We added two raised corner platforms on either side of the stairs.
They make the perfect place for a potted plant!
We are in LOVE with this space after all we have done, including the fire pit we built with matching blocks.
Our backyard was pretty basic but now it’s beautiful and we spend as much time there as we can!
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First published 19 Sept 2013 // Last updated 29 Jan 2021