While retaining walls are a great way to keep your soil in place and prevent erosion, they can also be quite expensive to build. That’s why we’re showing you how to build a hollow block retaining wall on your own, using basic materials you can pick up at any local hardware store. The process is straightforward, and it won’t take long before you have a beautiful new retaining wall all by yourself.
Step 1: Plan your retaining wall.
Before you build a hollow block retaining wall, it’s important to plan the project. You can do this yourself or hire someone to help you out. You will need to know how high you want your wall and how far from your house or structure it should extend.
Step 2: Clear the area where the retaining wall is to be built.
Once the area where the retaining wall is to be built has been cleared, make sure it is free of debris and unwanted debris. This includes:
- Stones or roots
- Loose soil
- Grass or weeds
Step 3: Dig a foundation trench along the planned length of the wall.
Normally, you would dig the foundation trench along the planned length of your wall. To do this, use a shovel to dig out a trench that’s deep enough to fully support your hollow block retaining wall. This means that you will want to dig until you hit solid ground (assuming there is any at all), or at least until you reach a depth that’s deeper than what your hollow blocks are likely to be buried in. If possible, try not to make any turns along the way; aim for an even path with no sharp angles or sudden twists as this may cause cracking issues later on.
If possible, try not to make any turns along the way; aim for an even path with no sharp angles or sudden twists as this may cause cracking issues later on.
Step 4: Lay out the first course of blocks along the footing trench, placing them so they will not have to be cut to fit.
Lay out the first course of blocks along the footing trench, placing them so they will not have to be cut to fit. Use a level to ensure that each block is level with the top of the footing trench. Use a straightedge to ensure that each block is straight with the top of the footing trench.
In this step, you’ll lay out your first course of blocks and make sure they are properly placed in relation to each other and to their surroundings. You’ll also check for plumb (straight up and down) alignment with respect to your reference points at this time as well as making sure that every block has been properly set into place so there are no gaps between any two adjacent pieces in this row before moving onto laying out any additional courses above or below it.
Step 5: Fill empty cells in hollow blocks with crushed stone and compact it with a tamper.
Now that you’ve used the hollow block to create a wall, it’s time to fill in any empty cells and compact the stone so that your wall is solid. Fill each cell with crushed stone and compact it with a tamper. If you were to use your foot instead of a tamper, it would be much more difficult to get an even fill throughout all of the cells—and this would result in uneven load distribution on top of your retaining wall.
Step 6: Lay a plastic mesh sheet on top of the first course, overlapping the joints by at least 8 inches.
Lay a plastic mesh sheet on top of the first course, overlapping the joints by at least 8 inches.
The mesh sheet is used to keep the blocks in place during construction and should be laid down before laying more blocks.
Step 7: Lay down another course of blocks on top of the first one.
Lay down another course of blocks on top of the first one. Make sure that these blocks are level with each other, level with the ground, level with the top of your footing trench and also level with the top of your previous course. Once you have laid down this second course, move in on either side of it and fill in any gaps (with more mortar mix) until you have built up enough to reach the bottom edge of your footings.
Step 8: Add another plastic mesh sheet over the second layer before adding more courses of blocks.
The next step is to add another layer of blocks, this time using three hollow blocks for each course. The process for laying the second layer is the same as before, except that this time you’ll be placing the plastic mesh sheet over the second layer before adding more courses of blocks.
The purpose of burying a plastic mesh barrier in your retaining wall is so that it prevents soil from washing out from beneath it when it rains or snows. Ideally, you should bury this mesh near the base of your wall—between 1 foot and 1 ½ feet below ground level—and maybe even further down if necessary (depending on how much rain/snow falls in your area).
Step 9: Backfill behind the retaining wall with soil and compact it in layers with a tamper.
Now that the wall is built, it’s time to backfill behind it. This is where all of your hard work will go towards creating a solid foundation for your retaining wall.
- First, make sure you have enough soil available in order to fill in between the blocks. If not, then simply add more soil and compact it again until it’s level with the top of your retaining wall.
- You can use a tamper to compact down this new layer of dirt (or use a shovel if no tampers are available). To ensure that you do not compact either too much or too little dirt by hand-tamping alone, follow these guidelines:
- Don’t tamp down like crazy on one area; otherwise you’ll end up with an uneven surface after all layers have been added and leveled out between each row of blocks—you just want even layers around each block!
- Take care when leveling out layers so as not to remove any additional material from areas where no material should be removed at this point (like making sure there aren’t big gaps between adjacent rows).
Building a block retaining wall yourself can be quite a rewarding experience if you take small steps and follow the instructions above carefully.
Building a block retaining wall yourself can be quite a rewarding experience if you take small steps and follow the instructions above carefully. It is very important to plan your wall first, as this will help prevent any problems or issues which may arise during the build process.
You need to clear the area where you are going to build your block retaining wall and make sure it is level. You also need to dig a foundation trench around two feet deep in order for each course of blocks to sit on properly. After digging out enough space for laying blocks, it’s time to lay out the first course of blocks on top of the foundation trench; this will give them something solid underneath them so they don’t shift or move when stacked together later down below ground level (i.e., within their own supporting space).
A block retaining wall is fairly easy to build and does not require any special skills other than basic masonry. You can also hire professionals to do the job for you if you have a large area that needs work. It is important that you follow these instructions carefully and make sure to hire a professional as needed, so your wall will last for years.