A freestanding block or stone patio wall is a functional and eye catching landscaping feature. Here’s how to build one…

If you are thinking about including a patio in your new landscaping, consider adding a freestanding patio wall. A freestanding wall makes a striking accent to a patio. In addition, it provides a ledge to sit on and adds a touch of privacy. Although they may look complex, with a bit of knowledge, skill, and hard work you can do it yourself, or you can hire a landscaper to do the job.

This quick guide will show you one method for installing a block wall. There are multiple ways of doing it depending on materials, site specifications, and personal preference.

The following procedures apply to a wall we built in San Luis Obispo using MorroStone from AirVol Block. This wall was built at the same time as a patio. If you already have a patio, a wall can be still be added. Depending on the specific patio, the steps may or may not change.

Step 1: Layout

The first step is to mark out where the wall will be located. You can use stakes and string line, a garden hose, or marking paint for this. By marking it out, you will get a visual of where the wall will be located, the shape of the wall, and the dimensions. You can make adjustments as needed before moving on to the next step.

Step 2: Excavate

You will most likely need to do some excavation in order to make room for your wall base and setting bed. We recommend digging about 6-8 inches deep and 6 inches wider than the footprint of your wall on each side. This will enable you to lay down a nice and thick 4-6 inch base layer and have some extra stability on the edges of the wall. As you see in the photo, it usually makes sense to do the excavation at the same time as the excavation for your patio.

When you get to your 6-8 inch depth, make sure to get the level and grade stakes out to make sure the base for the wall is nice and level. Keep in mind that the level of the wall will often be slightly different than the level of the patio. Your patio will need to be sloped at a 2% grade for drainage, but that’s a different topic.

Step 3: Install the Base

After you have the excavation work done and you are sure the ground is level, it’s time to build the wall base. Think of this as the foundation. It needs to be stable and firm in order to keep the wall from shifting and sinking. Just like the excavation step, if you are building a patio with the wall, you’ll likely build the base for both structures at the same time, keeping in mind the grading differences.

To start out, you’ll need to make sure the ground is firmly compacted. Use a hand tamper or plate compactor for this. You can rent a plate compactor at Rental depot in SLO or at Oasis Rentals in Los Osos and Morro Bay.

After the soil is tamped down, spread your base layer out evenly throughout the excavated area. For a base layer you can use decomposed granite, or Class 2 gravel base. If you are in San Luis Obispo, you can get these materials at Central Coast Landscape Products off Prado Rd. or at AirVol Block off of Suburban.

You want to have at least a 4″ depth for your base after it is compacted, but sometimes a 6″ base is necessary. This means you’ll need to add a little more than 4-6 inches of base initially to make up for the depth that is lost with compaction. Spread your base out and then wet it down slightly before using your hand tamper or plate compactor to pack it down. To get the base fully compacted, we recommend tamping down only a few inches at a time. Start with 2 or 3 inches of base – tamp it down – then add the rest and tamp it down again.

Make sure to check the level of your base before moving on to the next step.

Step 4: Install the Setting Bed

The setting bed is simply a 1 inch layer of concrete sand that is spread out above the base layer. This is what you will place the blocks on.

Spread out the sand evenly over the compacted base, checking the thickness throughout. Be careful not to step on the sand or get it wet.

Step 5: Install the First Course

A course is simply a row of blocks. Depending on the height of your wall, you will have several courses. The first course is the most critical because it sets the stage for the rest of the blocks. Spend extra time making sure that this course is absolutely level.

Use a rubber mallet to tamp down each block into the sand, continuing to check for level as you go. In addition to checking the level of the blocks, ensure that they are flush with each other. Again, take the extra time at this stage to make sure it is perfect before moving on.

Step 5: Lay the Rest of the Courses

After the initial course is set, things get easier. From here, it is a matter of stacking on the rest of the blocks.

Depending on your wall, you may want to stack the blocks in a particular pattern. If so, we recommend sketching out your pattern ahead of time to make the construction go a little smoother.

Another variable is whether or not your wall will require mortar or adhesive. Some blocks, such as MorroStones, which is what we used in the pictured wall built in San Luis Obispo, do not require any mortar or adhesive. In this case, we opted to use concrete adhesive to provide extra stability for the wall. It is easy to apply – simply use a caulking gun to draw a line of the glue over the blocks before installing the next course.

As you lay the blocks, step back often to check and make sure everything looks right. There’s nothing worse than finishing a wall and then realizing you made a mistake that you’ll have to go back and fix.

A typical sitting wall height is 18″-24″, but yours can be more or less, depending on your preferences and the blocks you are using. Some walls will have blocks on top called capstones. In some cases this can add a nice touch and can be accomplished either by using a pre-made capstone or by turning the last course of blocks 90 degrees to lay perpendicular to the other blocks.

Step 6: Enjoy!

That’s about it! Now you have a quality built sitting wall for your patio. Besides the added functionality of having a block wall with your patio, you will enjoy the way it adds a vertical dimension to an otherwise flat hardscape. Keep in mind that your specific circumstances or materials may require an alternative installation method. If in doubt, contact a professional for assistance.

If you are in SLO County and need help building your patio or block wall, give us a call. In addition to our other sustainable landscaping services, we build environmentally friendly and permeable patios and hardscapes. These green alternatives to impermeable surfaces decrease stormwater runoff by allowing the water to absorb into the ground. The future health of our local environment depends on this type of smart, ecologically based design. Thank you for landscaping responsibly!