What is Artificial Turf Infill? How To Choose The Best Infill Material For Your Artificial Grass

Artificial grass, also known as synthetic turf, has gained significant popularity as a low-maintenance alternative to natural grass. It’s rapidly increased in popularity for various applications such as residential lawns, dog runs/pet areas, sports fields, playgrounds, and more. 

However, what often goes unnoticed beneath the lush surface is the crucial role of infill material. Infill, the material tucked between the synthetic grass blades, is more than just a filler—it’s the unsung hero that ensures stability, durability, and safety in artificial turf installations. 

From enhancing drainage to reducing odors and providing cushioning, infill serves as the backbone of artificial grass systems. It makes turf installations more resilient to the demands of various applications. 

In this comprehensive guide, we delve into the world of infill, exploring its significance, different types, and why artificial grass needs it. Whether you’re a homeowner considering synthetic turf for your backyard or a sports field manager looking to optimize playability, understanding the importance of infill is key to achieving the best results.

What is Artificial Turf Infill? 

Infill: noun | in·fill – “Material that fills or is used to fill a space or hole.” – Merriam Webster

Infill refers to the granular material used to fill the space between the blades of artificial grass. The infill material is spread over the top of artificial grass, typically using a dropspreader. The turf fibers are then agitated, which causes the infill material to settle and fill the spaces between turf fibers.

Traditionally,  artificial turf infill options were limited to sand, crumb rubber, EDPM, and TPE. That’s no longer the case, as recent years have seen the introduction of a range of new infill materials. From acrylic coated sand to synthetic rubber to organic options like cork, coconut, walnut shells, and more. No two infill options are exactly the same. Each infill material has unnique qualities and characteristics that make it suited (or not) to the needs of different residential and commercial turf applications.

Why Does Artificial Grass Need Infill?

Infill serves multiple purposes in artificial grass installations. Not all artificial grass requires infill material, but it is generally recommended for outdoor installations. One of its primary functions is to act as ballast, weighing down the turf and preventing it from shifting. It also surrounds the base of each individual turf fiber, helping to keep it upright and prevent matting. 

To help visuaize the role infill plays, let’s say you took a drinking glass and stuck a few straws in it. With nothing in the glass to support the straws, they would just lean against the upper rim of the glass. Fill the glass about ⅔ with sand and the straws will remain standing. That’s what infill does for turf fibers, just on a bigger scale.

Infill also creates a more realistic feel to the turf when you walk on it, mimicking the cushion of a natural grass lawn. It helps to protect the backing of artificial grass from the sun’s damaging UV rays, preventing premature product degradation. 

In a properly installed artificial turf system, infill constitutes 90% of the weight, impacting the turf’s performance more than any other component. In addition to keeping the turf in place, infill plays a crucial role in turf systems providing the following benefits:

• Stability: Supports the synthetic turf fibers
• Aesthetics: Prevents fibers from matting down
• Safety: Cushions falls & minimizes injuries 
• Drainage: Improves drainage & prevents water from accumulating
• Comfort: Mimics feeling of natural grass and regulates surface temperatures
• Durability: Enhances resilience & prolongs its lifespan by protecting against UV rays

Those are the primary functions of basically all infill materials. The turf market has seen the introduction of more advanced infill materials in recent years. Innovative infill products like T°Cool Infill and Envirofill have introduced some added benefits:

• Antimicrobial Protection: Prevents buildup of odors & bacteria
• Temperature Reduction: Lowers surface temperature through evaporative cooling 

Overall, infill is an integral component of artificial grass systems, playing a crucial role in their functionality and longevity.

Does All Artificial Grass Need Infill?

Technically, no, not all artificial grass requires infill material. While infill is highly recommended for most artificial grass installations, there are certain circumstances where it may not be necessary. For instance, in applications where the artificial turf is primarily ornamental and receives minimal foot traffic, such as decorative landscaping in indoor settings or on balconies, infill may be optional. However, even in these cases, the inclusion of infill can provide benefits such as improved stability and aesthetics.

Infill becomes particularly essential in high-traffic areas or applications where the artificial grass is subjected to intense use, such as sports fields, playgrounds, and dog runs/pet areas. Without infill, artificial grass fibers may flatten over time, leading to a less attractive appearance and diminished performance. Therefore, while not all artificial grass installations require infill, its use is generally recommended for optimal results and longevity.

How Much Infill Do I Need for Artificial Turf?

The amount of infill material your artificial turf needs depends on a few factors:

• Turf Application
• Type of infill
• Expected foot traffic
• Type of grass

A general rule of thumb is to use enough infill such that only the top ½” to ¾” of your grass is exposed. Use the following formula to calculate the amount of infill needed for your turf installation. First, you’ll need to know the pile height of the turf being installed and the total square footage of the project. 

To begin, divide the pile height of your turf by 2, multiply it by the square footage of your project, and then multiply that by 0.0833333 to get the number of cubic feet. This number is then multiplied by the infill weight per cubic foot to determine the total weight of infill needed in pounds.

According to the Motz Group, manufacturers of Envirofill and Safeshell infills, for residential applications, between 1.5 and 3.5 lbs. per square foot is a safe bet.

If you are ever unsure about the proper amount of infill required for your artificial grass installation, check with the manufacturer. You can usually find this documentation on the manufacturer’s website.

What Types of Infill Options Are Available?

One of the most important components of most artificial turf installations is the infill material. As the turf industry has grown, the number of infill options has increased significantly. Some brands offer infill products tailored to specific applications like pets, golf, sports, playgrounds, etc. 

New features, enhancements, and characteristics will continue to be added to create new infill products. However many infill options are introduced to the turf market, there are essentially four types of infill materials: sand, rubber, organic, and zeolite.

Silica Sand Infills

Silica sand is the second most widely used infill material and is the least expensive. It also serves as the building block of acrylic-coated infills. Manufacturers and turf companies have created their own brand names for the same product. Some of the more popular acrylic-coated silica sand infill options are Envirofill, T°Cool, DuraFill, WonderFill, Hydrochill, HeroFill, MellowFill, and Putting Green Infill to name a few.

Whatever you want to call it, acrylic-coated infills are essentially manufactured sand with rounder edges. The “rounder” edges of are less prone to compacting and provide better impact absorption.

Rubber Infills

There are a few types of rubber infills that can be used for artificial turf. The two main options are crumb rubber and EPDM rubber. Crumb rubber is made from recycled tires and is a popular and cost-effective choice for infill. However, crumb rubber has a tendency to become very hot in direct sunlight. Because it’s made from recycled tires, it tends to be the infill option most often associated with potential health concerns.

EPDM (Ethylene Propylene Diene Monomer) rubber is man-made and comes in just about any color. It’s generally thought to be safer than crumb rubber. Similar to crumb rubber, EPDM rubber is highly durable and provides excellent shock absorption, making it popular for athletic fields.

Organic Infills

Made from natural materials that are odor-free and non-toxic, organic infill has been steadily increasing in popularity. Most organic infill products today are made from things like walnut shells, wood fiber, coconut fiber, olive pits, and rice husks. All-natural, (usually) chemical-free, and compostable, they’re an increasingly popular choice for people who want to reduce their environmental impact — an interest that artificial turf systems already help serve. 

The organic materials boast a natural resistance to mold, mildew, and decay and allow for clean water runoff. Superior foot stability and pressure distribution is safer and less abrasive for athletes. And, with 100% recyclable materials, organic infill can be repurposed in an environmentally friendly way.

Zeolite Infills

ZeoFill is an organic infill made from volcanic ash minerals, considered the best for eliminating pet waste smells. It is generally considered the best infill to use to help eliminate pet waste smells. Zeolite is also very porous which helps to keep your turf cooler in direct sunlight compared to most rubber or sand infill options. For this material, you should use a heavier infill, such as sand, as your base infill and then add a secondary layer of Zeolite on top.