Installing A Flagstone Patio: Ground Cover Guide

Flagstone patios can be a beautiful addition to your backyard, giving it a natural and high-end look. The installation process is relatively straightforward and can be done without the use of concrete or special tools. Here's a step-by-step guide on how to install a flagstone patio with ground cover:

Step 1: Planning

Before starting, consider the placement, size, and shape of your patio. It's important to build your patio with a slight angle to ensure proper drainage and avoid puddling issues. Choose the size and thickness of your flagstones, keeping in mind that bigger stones are heavier and more expensive, while thinner stones may crack under heavy weight.

Step 2: Excavation

Mark the area where you want to install the patio. Dig down about 6-8 inches, depending on the thickness of your flagstones, to create a base for your patio. Remember to call your local utilities to avoid disturbing any underground lines.

Step 3: Gravel Base

Create a gravel base by adding 3-4 inches of compacted gravel to the excavated area. This step is crucial for ensuring a flat and long-lasting patio. Add the gravel in layers of 2 inches, packing it down well before adding more.

Step 4: Leveling Layer

Install a 1-inch layer of leveling material. Avoid using sand as it moves when walked on. Instead, opt for crushed rock or decomposed granite (DG), which packs down better and discourages weed growth. Level this layer using a mason line and a level to ensure a flat patio.

Step 5: Laying Flagstones

Start laying the flagstones from one corner, working your way towards the center. Place the larger stones around the perimeter to lock the smaller stones in place. Try to minimise cutting by puzzling the stones together and leave gaps between them for the ground cover.

Step 6: Leveling Flagstones

Go stone by stone and level each one by adding or removing DG underneath. This step ensures that the flagstones don't shift or move as you walk on them.

Step 7: Filling Gaps

Fill in the gaps between the flagstones with your chosen ground cover, such as soil or more DG. Spray the patio with water to lock in the stones, and your flagstone patio with ground cover is complete!

Choosing the right flagstone

Type of Flagstone

The type of flagstone you choose will depend on the desired aesthetic for your patio. The most commonly used types of flagstone for patios include bluestone, limestone, redstone, sandstone, granite, and slate. Irregular-shaped flagstone is perfect for casual, free-form designs, while cut flagstone with straight edges and square corners is more suitable for formal, geometric patterns.

Thickness and Size

Flagstone pavers must be at least 2 inches thick to prevent cracking or breaking. Thinner flagstones may crack under heavy weight, while thicker options are heavier and more expensive. Consider the size of the stones as well; larger stones will require less work to fit together but will be heavier and pricier.

Durability and Maintenance

Flagstone is known for its durability and can withstand harsh weather conditions without chipping or cracking. A flagstone patio is also easy to maintain, requiring only regular sweeping and occasional refilling of gaps with sand.

Design and Customization

Flagstone offers endless design possibilities due to its irregular shapes and sizes. You can create intricate patterns, lay stones in various arrangements, and even incorporate other materials to achieve a unique look.

Cost

The cost of flagstone can vary depending on the type, quality, and quantity required for your project. Natural flagstone is typically priced by the ton or pallet, with prices ranging from $10 to $12 per square foot.

When choosing flagstones for your patio, it is essential to consider the overall design, functionality, and budget. By selecting the right type, size, and thickness of flagstone, you can create a durable, aesthetically pleasing, and cost-effective patio that enhances your outdoor living space.

Preparing the ground

Before you start, make sure you have the right tools. You will need a spade shovel, a hand tamper or plate compactor, stakes (wood or steel), and an angle grinder with a diamond blade. It is also important to wear safety equipment, such as gloves and eye protection.

First, plan your patio. Consider the placement, size, and shape, as well as the grading. You must build your patio so that it drains properly, so it should be at a slight angle with a drop of about 1/8" per foot of the patio. Consider the size of the stones, as bigger stones will be heavier and more expensive, but will require less work to put together. Thinner flagstones will crack under heavy weight, so if you are building a driveway, use stone that is at least 2" thick. If you plan on installing an irrigation system or a gas fire pit, run the lines before building the patio.

Next, outline the patio. Use mason lines and stakes to mark out the area. If you are making a square or rectangular patio, measure diagonally between the corners to ensure they are the same length.

Excavate the area. Dig your base for the patio to a depth of at least 6-8" plus the thickness of your flagstone. Start by digging around the edges of the patio and then move to the centre. Tamp the soil when you are done. The depth of your base may need to be adjusted depending on the natural drainage of your soil.

Now, lay the gravel and stonedust. Add a minimum 6" layer of compactible gravel to the whole area. Level the gravel with a rake and tamp it down. Do this in two steps, adding half the gravel first and tamping it down before adding the rest.

Once your gravel base is down, add a layer of levelled sand or stonedust and tamp it down. Level the surface with a screed or 2x4. Your entire base should now be compacted and levelled.

Laying the foundation

Planning and Preparation:

Before you begin, it's important to plan the size, shape, and location of your patio. Consider factors such as drainage, grading, and stone size and thickness. Call your local utilities to ensure you don't disturb any underground lines, and decide whether you'll be using the sand or mortar method for installation. Mark the area with stakes and string to outline the perimeter. Ensure that the corners are square by measuring diagonally between opposing corners and adjusting the stakes as needed.

Excavation:

Excavate the area within the marked perimeter. The depth of excavation depends on the thickness of your flagstone and the type of base you'll be using. A good rule of thumb is to excavate to a depth of at least 6-8 inches, including the thickness of your flagstone. For example, if your flagstone is 2 inches thick, excavate to a depth of 8-10 inches. Tamp the soil once you're done digging.

Base Layer:

Create a stable base layer to prevent your patio from shifting and becoming uneven over time. Start by adding a layer of compactible gravel, at least 2-3 inches thick, and preferably 6 inches or more. Rake the gravel smooth and level it, then tamp it thoroughly. Add the gravel in layers of 2 inches at a time, compacting each layer before adding more.

Sand or Stone Dust Layer:

On top of the gravel base, add a layer of sand or stone dust, also known as decomposed granite (DG). This layer should be about 1-2 inches thick. Level the surface of the sand or stone dust using a screed or a long, straight 2x4 board. Spray the layer with water to dampen it, then tamp it down thoroughly. Level it again if necessary.

Your foundation is now ready for the flagstone installation! Remember to wear proper safety gear, including gloves and eye protection, during the entire process.

Arranging the flagstones

Organising Your Flagstones:

Begin by sorting and arranging your flagstones in a broad, flat area nearby, such as your driveway. This step will help you visualise how the different sizes, colours, and shapes can come together. Try to create a pattern that varies in these elements, and don't be afraid to experiment. You can also take a picture of your design for future reference. If you're feeling confident, you can place the stones directly on the base and adjust them as you go.

Laying and Levelling the Flagstones:

Now, it's time to transfer your design to the actual patio. Start from a corner and work your way towards the centre, maintaining the same distance between the stones as in your pattern. Use a level to ensure each stone is even, and adjust them by adding or removing the underlying sand or stone dust. Remember, the goal is to create a stable and level surface where no stone sticks up and creates a tripping hazard.

Filling the Gaps:

Once your flagstones are laid and levelled, it's time to fill the gaps between them. You can use various materials for this step, such as sand, decomposed granite, gravel, or even soil if you plan to plant moss or other ground cover. Sweep the material across the patio, and then use a garden hose to settle it into the cracks. Repeat this process until all gaps are filled and level.

Final Adjustments:

After filling the gaps, inspect your patio for any uneven stones and make the necessary adjustments. Ensure that the entire patio is level by checking with a level and making any final tweaks.

Remember, when arranging your flagstones, it's essential to take your time and work carefully. This step is crucial in achieving a professional and aesthetically pleasing result. Don't be afraid to make changes to your original design as you go, as sometimes, adjustments are necessary to create a functional and stable patio.

Finishing touches

Now that you have laid the flagstones and filled the gaps, there are a few more steps to take to ensure your patio is safe, secure, and looks its best.

Inspect and Adjust

First, inspect the patio for any uneven stones and adjust as necessary. You can do this by checking each stone with a level and adding or removing the base material underneath to ensure they are sitting at the correct height. This is important to make sure your patio is safe and comfortable to walk on and that water will drain off effectively.

Sweep and Refill

Regularly sweep your flagstone patio to prevent a buildup of debris. Over time, you may find that the gaps between the stones need to be refilled. You can do this by brushing masonry sand into the cracks and misting the patio with water to settle it. Repeat this process until the gaps are filled and level. This will help to keep your patio looking neat and tidy and will also discourage weed growth.

Seal Your Patio

You may wish to seal your flagstone patio to protect it from stains and weather damage. This will help to enhance the natural colour and beauty of the stone and make it easier to clean and maintain.

Choose an Edging

Finally, you can add an edging around the perimeter of your patio to provide a finishing touch and help keep the stones in place. There are various options to choose from, including bricks, pavers, or metal edging. This will give your patio a neat and polished look and feel.

Frequently asked questions