These instructions are intended as a general guide for walls less than 4 feet only. Please consult the technical specification sheet for the wall shape you choose for more specific installation instructions.
Technical information for CypressStone™, Roman Cypress™, and CornerStone® walls over 4 feet requiring engineering and reinforcement are available from a Mutual Materials Representative.
Before beginning a retaining wall installation project, you first need to make sure you have the right tools for the job and have selected your retaining wall blocks. See Detailed List Below.
With the tools and equipment, you are now ready to start building your retaining wall. First mark the area of the wall with chalk or spray paint.
Dig out a trench that is a minimum of 6″ (155 mm) deep plus 1″ for every foot of wall height. Allow 6″–8″ (150–200 mm) of space behind the wall for 3⁄4″ clean crushed rock (this means your trench is a minimum of 12″ or 305 mm wide). Roots and big rocks should be removed from the trench. When the trench is dug out, put 3″ of 5⁄8 minus crushed rock in the trench. Tamp (compact) the base and level it front to back and side to side.
Lay the base course of retaining wall blocks. Using a string line at the back of the blocks for alignment, place blocks side by side on the gravel, checking for level in both directions.
TIP: Begin laying block at the lowest point of the wall. It is also easier to start at a straight part of the wall.Complete the base course before proceeding to the second course.
Start placing the second course. Center each block on the seams of the first course.
If using ManorStone®, CottageStone® Advantage, or VineyardStoneTM the connecting lip should be pointed down to overhang the back edge of the base units.
If using RomanStack®, StackStone®, CypressStone™, or Roman Cypress™, the bottom groove should be fitted over the tongue on the base blocks.
If using Celtik Wall®, insert clips as shown on the Celtik Wall® Tech Sheet. This will provide a batter to the wall for better stability. If using CornerStone® the connecting lugs should be pointed down to lock into the cores of the block below them.
To cut blocks for the ends of the wall or in tight curved sections, use a hammer and chisel to score the unit on all sides. Pound the chisel on the score line until the unit splits. Always wear eye protection when splitting blocks. If many cuts are needed, a saw rental may be the way to go.
After each course is laid, backfill behind wall with washed 3⁄4″ gravel or drain rock and compact in 3″ to 4″ layers. This step is important to help drainage and to prevent soil from leaching through the wall face.
For an additional safeguard, landscape fabric can also be used between the backfill and the drain rock.
To help drainage behind taller walls, perforated flexible drainpipe should also be used. Slope gravel behind wall so that the pipe laid behind the wall slopes 1″ (25 mm) for every 4′ (1.2 m) toward the desired run-off area.
If using RomanStack®, StackStone®, Celtik Wall®, CypressStone™, RomanCypress™ or CornerStone®, place the final layer using cap units for a finished look.
An option for finishing the wall is to secure the top course with construction adhesive. Apply a bead of adhesive with a caulking gun. Lay the top course down on the bead and press firmly.
Finish back filling behind the wall.
Do you still need to figure out the square footage for your project? Estimate the amount of retaining wall blocks you’ll need for your project with our project estimator tool.
Kendall: Well, we’re ready to get started so it probably makes sense to talk a little bit about the tools we’re going to need for the job.
Marty: Right, most of the tools you’re gonna find around your house already, you’re gonna have a round point shovel, great for, you know, if you’ve got plants to move like we do. Digging and starting the footing, a square bladed shovel for grading and for putting in the aggs, the base rock that we’re going to do a rake obviously for raking out level, a tamper, a pick. Hopefully we don’t have to use a pick, but it’s always a good idea they have one.
Kendall: Now does that depend on the type of soil we’re looking at?
Marty: Yeah, you know the Seattle area- a lot of rock, a lot of river rock so we’re famous for that and clay and a pick is a great tool for that. A level, different hammers, you got a mallet and then a pound Maul again for driving stakes, and a caulking gun and adhesive if we have to glue our cap down and if we’re gonna do any steps, which on this project, we are going to do.
Kendall: Well, that’s very good and we’ll talk about all these tools kind of as we move through the process, one by one.
Kendall: So, next step is to talk about the type of wall we’re going to use for the project and we’ve chosen Romans stack stone for this one.
Marty: Right, Roman stack stone is a vertical stack wall stone that’s rated at two feet high. There are five different components within Roman stack, so you give it a kind of a random stone look it’s faced on both sides because so it can be used as a divider or a garden wall it can be a serpentine or straight.
Kendall: Okay, and if I rated at two feet tall that means that’s the highest you can go with it right?
Marty: Right, that’s the recommendation.
Kendall: All right very good and when you say it’s two feet high I know part of the wall is buried underground– is it two feet from the bottom block or from the ground?
Marty: From the ground, essentially is what you want to do.. and again, you know, the weight of the block is what determines the strength and you really don’t want to exceed that.
Kendall: All right, very good. And are there other types of block we could use in a project like this?
Marty: Right. There are several other types of block and size and colors to choose from. Most of the others have a lip on the back and they have a batter so they step back each course.
Kendall: Okay
Marty: And then they’re larger and size heavier which, again, means they’re going to hold in place and you can stack a little bit higher maybe rated up to four feet.
Kendall: All right, well, let’s talk about a couple of those different kinds of blocks.
Marty: What you got here’s the Roman stack stone again here’s the five different components there’s two caps a 12 and an 8 – the field stone, again, and with a Roman stack you have a slot in the middle and then this channel on top that receives that studies and they stack vertically and again split front and back you have an 8 by 8 jumbo a 12 inch and an 8 inch that can be used again randomly to make your wall more interesting and then we have a 90-degree corner. So, if we want to turn 90 degrees, which we’re going to use on this project, for steps, you have that available as well.
Kendall: It looks like they’re pretty easy. They just kind of all fit into each other?
Marty: Right, these are angled already so we can alternate them to do a straight wall or turn them around to do a radius.
Kendall: Ah, OK.
Marty: Oh, so very easy to use. Very simple and then again cutting we would be using our hammer and chisel or the saw and splitting those in half.
Kendall: Well, let’s talk about the other blocks that are available.
Marty: Right. We have a manor stone, which is 6 by 16 and weighs 60 pounds and then a cottage stone 4 by 12 which is 40 (lbs.) ok and these are a lip block.
Kendall: So, what’s the difference there, can you show us?
Marty: Sure, so you have a lip on the back of the block that just really helps you align the block. So, this would sit on top and the next course would sit on top and the lip would you have butt that out and that would align the block, the lips can be aligned for the base course.. but, again, it’s a just kind of a tool to help you line the block up.
Kendall: But.. with the lip you’re not able to do a vertical wall, correct?
Marty: Yeah, that’s the way that lip works; is it’s going to give you a 3/4 inch to 1 inch set back and you need to keep that in mind when you’re laying your wall out- that if you’re going to go four or five courses high, that the wall’s gonna be, you know, four or five inches back behind, you know, set back. So, keep that in mind when you’re digging your footing.
Kendall: Oh, great. Well, let’s go ahead and get started!
Summertime is backyard improvement season for homeowners and it seems that many people enjoy the cost savings and sense of satisfaction of completing a Do-It-Yourself (DIY) landscaping project. Building with retaining wall block is a popular choice for DIY landscaping projects ranging from raised garden beds to taming hillsides and creating terraces or stairways. Not sure what you want to build? Here are some retaining wall ideas and inspiration projects.
For the DIY enthusiast, the good news is that most of the tools you will need to build retaining wall projects are common.
Round point shovel
This is helpful for when you have plants to move, digging and starting a footing.
Square blade shovel
Good for putting in aggregates like gravel or sand and grading the area.
Rake
Helpful to level out the base rock.
Tamper
Tamping down areas.
Level
Determine if the work area and retaining wall rows are level.
Hammers
It may be helpful to have a mallet and a 5-pound maul to drive stakes into the ground.
Pick
You might not need this, depending on your type of soil. Picks are useful to loosen hard and rocky soil.
Caulking gun and adhesive
These optional items will be useful if you want to glue finishing caps or add steps
Here’s a quick video about the tools you’ll want for installing retaining walls. This short video is part of an entire series of retaining wall installation videos that you can find on our website.