Artificial Grass

What is Under Artificial Turf – Complete Guide on Sub Base Materials

Artificial turf is a surface made out of synthetic fibers that resemble natural grass blades.

These surfaces were initially introduced in sports that have historically been played on grass like Hockey, Futsal, and Golf.

However, synthetic turf has now become a very popular option for residential lawns and even some commercial settings.

If you’re planning to get your own artificial turf for any of the above reasons, you may be thinking, what exactly goes under artificial turf? Well, you’re at the right place.

In this guide, we’ll deconstruct the entire structural composition of synthetic turf just for you.

What Is Under Artificial Turf

A lot of people are unaware of the structural components of artificial turf.

Starting from the sub-base and going right to the synthetic fibers at the top, there are several layers of natural and man-made materials that constitute the entire functional unit of the turf.

Base of Artificial Turf

The base of the artificial turf also referred to as the “sub-base” is the foundational surface of any synthetic turf.

If the base is not installed properly, the turf structure might fall apart.

Contrary to popular belief, artificial turf doesn’t necessarily need to be installed over soil or dirt. You can lay the turf on

  • Concrete
  • Patios
  • Decks
  • Pool areas

Heck, you can even use it as an indoor carpet.

However, if you do plan to place the turf on top of soil or dirt, you will need to install a sub-base before anything else.

Purpose of Base for Turf

The base of artificial turf serves several important purposes:

  • Increases the life of your artificial turf
  • It strengthens the turf
  • Allows it to bear the load of foot traffic and any other items that are placed on top of it

Intrinsic properties of soil cause it to contract and expand in response to varying temperatures and climates.

The surface of synthetic grass is designed to be porous so that water doesn’t accumulate on top. If the sub-base is not installed properly, it could lead to wrinkles and gaps in your turf.

In the case of a poorly fitted sub-base, the turf surface can become uneven with dips that might even cause accidents. Essentially, the base provides structural stability to your synthetic turf.

Weed Fabric / Barrier

As a common protocol, it is recommended that you carry out the proper excavation of the site where you plan to install the artificial turf.

Once this is done, the sub-base can be added and you are good to go.

Excavation is usually performed to ensure that there is no undergrowth in the area that has been selected for installation of the turf.

However, if you didn’t do enough excavation, or there is contamination in your sub-base, it may result in an outgrowth of weeds from between the drainage pores on the turf surface.

To prevent this from happening, a weed barrier is generally used as added protection.

Why Use Weed Barrier Under Artificial Turf?

A weed barrier, also called a weed membrane can help prevent the growth of weeds and maintain the aesthetic of your artificial lawn.

This membrane is usually installed underneath the sub-base but setting it on top of the material you’re using for the drainage layer, for example, granite dust will also suffice.

Structural Stability

The membrane also adds structural stability to your turf. Furthermore, modern weed barriers are well-perforated so they do not hamper the passage of water or other fluids.

Helps Drainage

This feature is also beneficial for pet owners who may be worried about the drainage of waste fluids from their artificial turf.

Stones or Crushed Rocks

Large stones and crushed rocks form an important component of the sub-base of any artificial turf.

Different types of crushed stones and sediments are mixed to form what is known as gravel.

Typically, the gravel materials used in the preparation of the sub-base include:

  • Crushed granite
  • Sandstone
  • Other aggregates

The ideal size of stones for the compaction process ranges from anywhere between three-eights to three-fourths of an inch.

The reason behind maintaining the stone size under 1 inch is because it allows the grass to retain a relatively flat surface.

Why Use Stones Under Artificial Turf?

The primary reason for using stones and crushed rocks, especially gravel is to create a sub-base that is permeable but compact at the same time.

This ensures that the turf’s drainage field is intact and does not hinder the flow of water or other fluids trickling down from the surface while also maintaining the structural integrity of the turf.

Filler Material Like Limestone and Granite

Before we specifically talk about limestones and granite, let’s first understand what filler material is.

What is Filler for Artificial Turf?

After initially setting the sub-base with larger rocks and stones, filler material, more commonly referred to as “fines”, is used to surround the rock base in order to provide greater stability to the overall structure.

The size of the filler material generally varies between a maximum of one-fourth of an inch to as small as minute dust particles.

The most commonly used filler options are limestone and granite.

In some turf installations, even silica or sand may be used as alternative fines to ensure turf stability and smoothness.

Why Use Filler Material Under Artificial Turf?

Filler material or infill is a major component of any type of artificial turf installation.

Support Turf Fibers

Its purpose is to support the artificial grass blades, keeping them upright. Basically, it performs the same function as the nutrients present in soil under natural grass.

Thus, the infill helps to increase the turf’s resemblance to natural grass, making it feel softer to the touch.

Help Drainage

Furthermore, filler materials like limestone and granite maintain the integrity of the sub-base while also playing a role in setting up an effective drainage field for fluids to pass through.

Rubber or Foam Padding for Hard Surfaces

If you are planning to install artificial turf on top of a hard surface like patio or concrete, it’s a good idea to install a cushioning surface first.

In most cases, rubber or foam padding is the most suitable and cost-effective option to be inserted under artificial grass.

It has excellent shock absorbing properties, making it a perfect fit for use in sports fields and in residential settings where you can rest assured that your children will be safe from impact injuries.

Why Use Rubber Padding Under Artificial Turf?

There are many reasons for installing a rubber pad underneath your artificial turf.

Generally, artificial turf is installed over a hard compacted sub-base to keep the surface as flat and smooth as possible.

While there is some extent of cushioning added to the synthetic grass fibers along with the padding effect of the filler materials, the turf surface may still be quite stiff and hard on impact.

To Prevent Injuries

If you’re installing playground turf for kids, it is imperative to add a layer of rubber padding underneath the turf so that injuries from falls on the playground can be minimized.

To Add Shock Absorption

Similarly, artificial sports turf can also benefit from the impact absorbing properties of rubber padding, as it adds safety and resilience to the overall structure.

To Add Comfort

Rubber padding is also a great option for residential lawns as it provides increased safety and softness. It makes the turf more delicate and comfortable to walk on.

In addition, rubber pads can help to prevent excessive splashing of infill onto the turf surface. It does this by lowering the height of the fiber pile and increasing its density instead.

Nowadays, shock pads are regarded as an extra layer of protection, both for the turf and the people using it.

Drainage Tiles

Drainage tiles are specially designed to provide a flow-through base for artificial turf.

The perforations within the tiles allow moisture to trickle down from the surface, preventing it from pooling between the synthetic grass blades.

Besides, drainage tiles installed under artificial turf provide a passage for airflow so that the moisture that has accumulated at the level of the subfloor can be evaporated.

This helps to prevent the undergrowth of mold, mildew, and weeds.

When to Use Drainage Tiles

You will need to install drainage tiles underneath your turf if you expect to have an excessive discharge of fluids on the synthetic grass.

For Pet Turf Projects

For example, if you’re a pet owner, the drainage tiles will help ensure that the waste fluids are drained properly so that the turf is kept clean and sanitary.

For Niche Projects Like Roof Turf Installation

Also, if you are planning to install artificial turf on your roof, adding the tiles will be imperative to prevent moisture from accumulating on its surface and ruining the aesthetic.