Best Sub-Base for Artificial Grass (how to install guide)

When it comes to installing artificial grass, the sub-base is often an afterthought. The sub base is the foundation of your artificial grass installation, but what is the best sub-base for artificial grass?

The best sub-base for artificial grass is crushed rock or gravel. This material provides excellent drainage, and stability, and allows for proper compaction. Additionally, it is a durable and long-lasting option that can withstand heavy foot traffic and weather conditions.

Simply put, the sub base is the layer of material that rests between your final layer and your artificial turf. It serves as a support system for your turf while also helping with drainage and preventing ground movement.

In other words, it’s what keeps your synthetic lawn looking good year after year. Without a solid foundation, your artificial grass will not perform optimally or have an extended lifespan compared to one with a well-built foundation.

A poorly installed or non-existent sub base can cause shifting and cracking of the surface layer which ultimately leads to an uneven lawn appearance.

It can also contribute to drainage issues during rain or snowfall. Installing an appropriate sub-base may seem like an unnecessary expense at first glance.

However, when correctly installed by professionals who understand how different materials react in various weather conditions and soil types then you ensure that you will have great-looking turf for years to come!

sub base artificial grass

Types of Sub Base Materials for Artificial Grass

When it comes to choosing the right type of sub base material for your fake grass installation, there are a few options to consider. Each material has its own set of pros and cons, so it’s important to understand what each one offers before making a decision.

Crushed Stone: Pros and Cons

One popular artificial grass base is crushed stone. Crushed stone is made from rocks broken down into small pieces, typically about 1/4 inch in size.

One of the biggest advantages of using crushed stone as your sub base material is its durability.

Crushed stone is extremely sturdy and can withstand heavy foot traffic without becoming damaged or compacted over time. Another benefit of using crushed stone as your sub base material is its ability to promote proper drainage.

Because the stones are small and porous, they allow water to seep through easily rather than pooling on top of the surface. However, one potential drawback of using crushed stone as your sub base material is that it can be slightly more expensive than other options.

Decomposed Granite: Pros and Cons

Another option for sub base material is decomposed granite dust (DG).

DG is made from granite rock that has been broken down into even smaller pieces than crushed stone – typically ranging from sand-sized particles to 1/4 inch pieces.

One advantage of using DG as your sub base material is its affordability – it’s often less expensive than other materials like crushed stone or road base.

In addition to being cost-effective, DG also offers good drainage properties and creates a stable foundation for artificial grass installation.

However, one potential drawback of using DG as your sub-base material is that it can be more prone to erosion over time if not properly compacted.

Road Base: Pros and Cons

Road Base (also known as Class II Base Rock or Caltrans specification rock) is another common sub-base material for fake turf. As the name suggests, it’s often used as a base layer for roads and highways.

One of the benefits of using road base as your sub-base material is its compactability.

Road base is typically made from a blend of gravel and fine particles, so it can be easily compacted to create a sturdy foundation. Another advantage of using road base is its affordability – it’s often priced lower than other materials like crushed stone.

However, one potential drawback of using road base as your sub-base material is that it doesn’t allow for much water drainage. If you live in an area with heavy rainfall or poor soil drainage, you may want to consider another option that allows for better drainage.

Can You Put Artificial Grass Directly On Soil?

While it is possible to install artificial grass directly on soil, it is generally not recommended.

One of the main reasons is that soil tends to retain moisture, which can lead to drainage problems and even mold growth.

Installing a base material, such as crushed stone or decomposed granite, can help to improve drainage and create a stable foundation for the turf. This can also help to prevent soil from shifting and causing unevenness or bumps in the artificial grass.

Another reason to avoid installing artificial grass directly on soil is that it can make it difficult to maintain the turf.

With no barrier between the grass and the ground, weeds, and other vegetation can grow up through the turf, making it difficult to keep the surface looking clean and well-manicured.

Additionally, without a base layer, the turf can be more susceptible to damage from foot traffic and other activity, which can lead to uneven wear and tear.

That being said, in certain situations where the soil is stable and well-draining, it may be possible to install artificial grass directly on the ground.

In these cases, it is important to ensure that the soil is well-compacted and level to prevent any shifting or unevenness. However, even in these situations, it may still be beneficial to install a base material to help improve drainage and ensure a more stable foundation for the turf.

Factors to Consider When Choosing a Sub Base Material

Climate and Weather Conditions

One important factor to consider when choosing a sub-base material for your artificial grass is the climate and weather conditions in your area.

If you live in a region with extreme temperatures, it’s important to choose a material that can withstand those conditions without cracking or shifting. For example, crushed stone may not be the best choice for areas with freezing temperatures as it may shift and create uneven spots in your lawn.

Soil Type

The soil type in your area is another important factor to consider when choosing a sub-base material for artificial grass installation.

If you have clay soil, you’ll want a sub-base material that provides good drainage as clay soil tends to hold onto water. Crushed stone or road base are good options for areas with clay soil as they provide better drainage than decomposed granite.

On the other hand, if you have sandy soil, you’ll want a sub-base material that can help compact the soil and prevent it from shifting over time. A road base is often a good option for areas with sandy soil as it provides stability.

Drainage System

Your drainage system is also important when choosing a sub-base material for artificial grass installation.

If you have poor drainage in your yard, it’s essential to choose a sub-base material that helps improve drainage and prevents water from pooling on top of your lawn.

Crushed stone and road base are both good options for improving drainage, but if you’re concerned about water buildup, you may also want to consider adding additional drainage solutions like perforated pipes or French drains.


Budget is an important consideration when selecting the right sub-base material for artificial grass installation.

While crushed stone may be more expensive upfront than decomposed granite, it may be a better long-term investment as it provides better drainage and stability. Consider your budget carefully and weigh the pros and cons of each sub-base material before making your final decision.

Preparing the Sub Base for Artificial Grass Installation

Excavation Process: Digging and Leveling

Before installing any sub-base, you must excavate the area to prepare it for your new artificial turf.

You will want to dig out the area where the grass will be installed, removing any rocks or debris that may be present in the soil.

You will also need to ensure that your digging is level by using a long level or laser level tool. Once you have dug out the area and leveled it properly, you are ready to move on to the next step.

Compaction Techniques: Getting It Right

The next step is compaction. This process involves compacting the soil underneath your newly excavated area so that it becomes solid and stable enough for your artificial grass installation.

For the best results, use a plate compactor, like this great one from Amazon. It’s important to push down on each section of soil with repeated passes until you reach a final compaction rate of 95-97%, which is crucial for overall stability.

Adding Weed Barrier: Keeping It Clean

The last step in preparing your sub-base is adding weed barrier cloth over the compacted soil before laying down any other layers of material like road base or decomposed granite.

A weed membrane prevents unwanted weeds from growing up through your artificial grass over time, making maintenance much easier as well as keeping an even surface underfoot while preventing weeds from ruining family fun days outside on your new lawn!

Be sure to overlap each piece by at least 6 inches so that there are no gaps for weeds to get through and ruin all of your hard work!

Do you put artificial grass directly on the sub-base?

It is not recommended to install artificial grass directly on the sub-base, which is typically made up of crushed stone or gravel.

Instead, it is best to install a layer of decomposed granite or similar aggregate material on top of the sub-base, and then compact it to create a stable base for the artificial grass.

The layer of decomposed granite or aggregate material should be about 2-3 inches thick and should be spread evenly across the sub-base.

Once it is in place, it should be compacted with a plate compactor to create a firm and stable surface. This will help to ensure that the artificial grass is installed on a level surface that will not shift or settle over time.

In addition to providing a stable base, the layer of decomposed granite or aggregate material will also help with drainage. This is important because artificial grass needs to be able to drain properly in order to prevent water from pooling on the surface, which can lead to mold and other problems.

Overall, while it may be tempting to install artificial grass directly on the sub-base, it is not recommended.

By taking the time to install a layer of decomposed granite or aggregate material, you can help ensure that your artificial grass is installed on a stable and level surface that will provide long-lasting performance and durability.

Can you use sharp sand as a laying course on top of the sub-base for artificial grass?

Yes, you can use sharp sand as a laying course for artificial grass, and many budget installers do.

However, it’s not the best option. Sharp sand is typically used as a bedding material for paving, and while it can provide good drainage, it doesn’t offer the same level of stability as other materials.

Using sharp sand as a laying course can also create uneven areas on your lawn, which can lead to issues with drainage and the overall appearance of your grass. It can also create a less-than-ideal environment for the grass roots to grow, as the sand may shift and compact over time.

The best practice for a laying course is to use a type of crushed stone, such as limestone or granite.

This provides a stable and level surface for the grass to rest on, and allows for good drainage. The crushed stone should be between 2 and 4 inches in depth, depending on the application and the condition of the sub-base.

Before laying the crushed stone, it’s important to ensure that the sub-base is properly compacted and level. This will provide the necessary foundation for the crushed stone and the artificial grass.

Common Artificial Grass Mistakes to Avoid

Overlooking Drainage Issues

One of the common mistakes people make when installing a sub-base for artificial grass is overlooking drainage issues. Proper drainage is crucial to prevent water buildup and seepage beneath the artificial grass surface.

If the sub-base isn’t properly sloped or compacted, it can lead to poor drainage and standing water, which can cause damage to your artificial grass over time. To avoid this mistake, you should ensure that your sub-base has an adequate slope and that it is compacted correctly.

You should also consider any existing drainage systems on your property and how they will affect the installation process. Make sure the drainage systems are incorporated into the design of your sub-base so that water flows away from the artificial grass surface.

Inadequate Compaction

Another common mistake when installing a sub-base for artificial grass is inadequate compaction. The purpose of a sub-base is to provide stability, support, and proper drainage for your artificial grass surface.

If it’s not properly compacted, it can lead to uneven surfaces and sinking areas that can compromise the overall integrity of your installation. To avoid this mistake, you need to use suitable equipment for compaction such as plate compactors or rollers with ample weight capacity based on soil type, etc.

Do not cut corners on this stage as even one un-compacted spot in a small area will create an imbalance in the support structure causing long-term ripples or bulges in turf.

Using the Wrong Type of Material

All materials used during installation directly affect the longevity and quality of the turf system installed thereafter.

For instance, using sand instead of crushed stone while setting up foundations leads to such materials settling over time reducing support structure and damaging the turf fibers. To avoid this mistake, you should consider soil type, climate, and weather conditions to choose a suitable sub-base material for your artificial grass installation.

Make sure you consult with a professional to determine the most appropriate material for your specific circumstances. Proper research saves from costly mistakes in the long run.


Choosing the right sub-base material for artificial grass installation is a critical factor that should not be overlooked.

The sub-base plays a vital role in ensuring the longevity and durability of your synthetic turf. By providing a stable foundation that can withstand environmental factors such as rainfall and snowfall, you can avoid costly repairs and replacements in the future.

And you can take full advantage of the benefits of your new artificial lawn compared to natural grass.

When selecting a sub-base material, it is essential to consider various factors such as climate and weather conditions, soil type, drainage system, and budget. Each of these elements will impact the type of sub-base material that will work best for your artificial grass installation.

The preparation process is also crucial to ensure optimal results.

Proper excavation and compaction techniques must be employed to create a stable ground surface that can support your synthetic turf’s weight without settling or shifting over time.

Adding a weed barrier further minimizes any potential weed growth beneath the turf. By avoiding common mistakes such as overlooking drainage issues or using the wrong type of material, you can maximize your sub-base’s effectiveness at providing long-lasting support for your artificial grass.

Overall, with proper research and planning, your artificial turf installation will go smoothly and stay within budget.

Remember: investing in quality now will save you money down the road by preventing costly replacements or repairs.

Image by PublicDomainPictures from Pixabay and Image by AADDLLSS Design and Art Direction from Pixabay and Image by Gerd Altmann from Pixabay

Middle Class Dad is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to As an Amazon Associate, I may earn a small commission from qualifying purchases if you click to Amazon from my site and choose to make a purchase. This is no way increases the cost to you.

Leave a Reply

Your email address will not be published. Required fields are marked *

Top Related Posts