Artificial Grass Underlay Explained: Types, Uses, and Expert Advice

Lumpy turf, soggy patches, or sore feet? The culprit might not be your grass—but what’s under it. Artificial grass underlay plays a bigger role than most people realize. In this guide, we’ll walk you through everything you need to know to choose the right base layer for a soft, safe, and long-lasting turf system.

We’ll begin by explaining what underlay is and whether you actually need it. Then, we’ll compare underlay options for different surfaces like concrete, soil, and decking, and break down the best materials—foam, rubber, polyurethane, and recycled blends. You’ll learn how to judge quality, install it properly, and avoid common mistakes. We also cover drainage solutions, safety choices for kids, and the difference between padding and underlay.

By the end, you won’t just know what to buy—you’ll understand why it matters.

What Is Artificial Grass Underlay and Why Does It Matter?

When installing artificial grass, the underlay—sometimes called turf underlayment or padding—is the layer placed between the ground and the synthetic turf. It’s often made from foam, rubber, or other resilient materials designed to support the surface above.

While it might look like an optional step, underlay plays a bigger role than many expect. It helps create a smoother, softer, and more durable surface. Without it, artificial grass may wear down faster, feel hard underfoot, or even drain poorly.

If you’re installing turf over concrete, decking, or any uneven surface, the underlay adds comfort and stability. For soil-based installations, it can help level the ground and improve drainage. Some types even include built-in shock absorption, which makes them perfect for families with kids or dogs.

In short, artificial grass underlay is not just a technical detail—it’s the foundation of a long-lasting, professional-quality installation. Skipping it might seem like a shortcut, but it often leads to a bumpy finish and costly repairs down the line.

Do You Really Need Underlay for Artificial Grass?

Whether you actually need artificial grass underlay depends on how and where you’re installing the turf. Some situations absolutely call for it, while others may allow you to skip it. In this section, we’ll walk through when underlayment is essential, when it’s not strictly necessary, and what common myths can lead to poor decisions.

When Underlay Is Essential

If you’re laying artificial grass over concrete, paving, decking, or compacted gravel, an underlay is a must. These hard surfaces offer no natural give, so the padding layer adds comfort, absorbs impact, and helps the turf last longer. It also levels out minor imperfections, preventing visible bumps or gaps.

You’ll also want underlay in areas where shock absorption or drainage is a priority—like playgrounds, pet areas, or yards that get heavy rain. In these cases, a quality shock pad or foam underlayment can make a big difference in performance and safety.

When You Might Not Need It

For turf laid directly over well-prepared soil or a full aggregate sub-base, underlay may not always be necessary. If the surface is already level, free-draining, and lightly cushioned by compacted sand or granite dust, your turf can go straight on top.

That said, even in these setups, adding a thin underlay can still improve comfort and extend turf life—so it becomes more of a “nice to have” than a must.

Common Misconceptions About Underlay

Some people assume underlay is only about softness. In reality, it also:

• Improves drainage
• Extends turf lifespan
• Reduces noise when walked on
• Helps turf look and feel more natural

Others believe it’s only for sports fields or playgrounds, but even residential gardens can benefit—especially in extreme climates or multi-use spaces.

Best Underlay Options for Different Surfaces

Choosing the right artificial grass underlay depends heavily on the surface you’re working with. Different base types call for different materials, thickness levels, and features. In this section, we’ll go through the best underlay choices for five common surfaces: concrete, soil, decking, hard ground, and pet areas.

Concrete

Concrete is one of the most unforgiving bases. It’s hard, unyielding, and can quickly wear down your turf if left unprotected. The best choice here is a foam underlay or shock pad, typically around 10–12mm thick. It cushions impact, evens out minor imperfections, and adds a soft feel underfoot. If water drainage is a concern, look for options with perforations or a drainage mat underneath.

Soil or Natural Ground

If you’re laying turf over well-compacted soil or a sub-base like crushed stone, you may not need a thick underlay—but a breathable foam layer can still help. It adds a touch of comfort, protects the turf backing, and smooths out minor dips. In areas with heavy rain, drainage-enhanced underlay is ideal to avoid pooling and muddy spots.

Decking

Wooden decking presents a unique challenge. It’s not level by default and often has gaps. A flexible roll-type underlay, like cross-linked foam, works well to bridge those gaps and create a flat base. The cushioning also reduces impact noise and prevents the turf from sagging into the deck grooves over time.

Hard Surfaces (Paving, Tiles, Gravel)

For surfaces like paving slabs or compacted gravel, go for a dense foam or rubber underlay. These help to level uneven joints and reduce the pressure that wears down turf over time. In high-traffic zones, durability is key—choose underlays rated for compression resistance.

Pet-Friendly Areas

In homes with dogs or other pets, hygiene and drainage become top concerns. Choose an underlay that’s non-absorbent, easy to clean, and odor-resistant. Many pet-specific turf systems pair antimicrobial foam layers with drainage channels to help keep the area dry and fresh.

Best Materials for Artificial Grass Underlay

The performance of artificial grass underlay depends largely on the materials used. Whether you’re looking for durability, drainage, softness, or eco-friendliness, choosing the right underlay material makes a big difference. In this section, we’ll look at the most common underlay materials: foam, rubber, polyurethane, and recycled blends—each with their strengths and use cases.

Foam Underlay

Foam is one of the most popular choices for turf installations. It’s lightweight, easy to cut, and offers a soft feel underfoot. Closed-cell foam types resist water absorption, making them suitable for both dry and moderately wet environments. Foam also comes in various thicknesses, giving you more control over comfort and fall protection.

That said, not all foams are equal. Lower-density options may compress over time in high-traffic areas. For lasting performance, go for cross-linked or high-density foam underlays with drainage holes if possible.

Rubber Shock Pads

Rubber underlay is prized for its shock absorption and long-term durability. Made from recycled rubber or vulcanized materials, these pads are excellent for areas where impact resistance matters—like playgrounds or sports zones.

Rubber is heavier and usually more expensive than foam, but it stays stable under heat and foot traffic. It also tends to hold its shape well, making it a solid choice for permanent installations on concrete or tile bases.

Polyurethane (PU) Underlay

Polyurethane underlays are engineered for both flexibility and performance. They’re often used in commercial or high-spec turf systems where comfort and resilience are top priorities.

PU pads are known for their uniform cell structure, which gives them a consistent feel across large areas. They also perform well in wet conditions, draining quickly without breaking down. However, they tend to be pricier than foam or rubber.

Recycled and Eco-Friendly Options

If sustainability is a priority, several manufacturers now offer underlay made from recycled foam, rubber, or mixed polymers. These products aim to reduce landfill waste while still offering solid shock absorption and drainage.

Quality can vary depending on the source material and process, so it’s worth checking performance specs carefully. But for many homeowners, recycled underlay strikes a balance between environmental responsibility and performance.

Key Features to Look for in Artificial Grass Underlay

Not all artificial grass underlay is made the same. The right turf padding should do more than just sit under your grass—it should actively support its look, feel, and performance. Below are four essential features to pay attention to when choosing an underlay: drainage capability, thickness, durability, and compatibility with your surface and turf type.

Drainage Capability

If water can’t escape efficiently, even the best turf will fail. A good underlay should allow rainwater to flow through quickly, especially in wet climates or yards without a slope. Look for underlay with built-in perforations or grooves that direct water away from the surface. For heavy rainfall areas, pairing the underlay with a permeable base layer is even more important.

Thickness and Cushioning

The thickness of your underlay directly affects turf comfort, drainage, and durability. Most products range from 10mm to 25mm. Use 10mm for patios or low-traffic areas, and 20–25mm for zones needing shock absorption, such as playgrounds or pet runs.

Avoid going too thick—excess padding can block drainage, raise edges, and trap moisture. Choose a thickness that offers comfort without compromising drainage or stability.

Durability and Compression Resistance

Artificial grass installations are meant to last years. A weak underlay can compress underfoot traffic, causing dips and wrinkles. Choose a product rated for outdoor use with proven resistance to wear, UV exposure, and temperature changes. High-density foam or rubber materials usually perform better in high-traffic zones like walkways or patios.

Compatibility with Turf and Surface

Some underlays work well on soil but slide on smooth decking. Others pair best with short-pile turf, while some support thick, heavy blades. Always match your underlay to both your base surface and turf type. If you’re unsure, consult the turf supplier for recommendations—many offer matched underlay solutions for best results.

How to Install Artificial Grass Underlay Properly?

Installing artificial grass underlay—or turf underlayment—is a crucial step to ensure a smooth, durable, and comfortable surface. If done right, it helps prevent sagging, enhances drainage, and extends the life of your turf. In this section, we’ll cover how to prepare the base, lay the underlay correctly, and avoid common mistakes.

Surface Preparation Matters First

Before you even unroll the underlay, make sure your base is clean, dry, and level. Remove rocks, debris, or weeds that could cause bumps. If you’re working with soil, compact it and add a layer of crushed stone or sharp sand for drainage. On concrete or decking, sweep the surface and check for cracks or loose boards. The flatter your base, the better your results.

Do I Need Landscape Fabric Under the Underlay?

No, in most cases you don’t need landscape fabric under artificial grass underlay. The underlay itself provides coverage and cushioning. However, for soil-based installs with weed concerns, a weed barrier can be added between the base and the underlay.

Step-by-Step Underlay Installation

Start by rolling out the underlay across the entire surface. Cut it to size using a utility knife, leaving no large gaps between pieces. If you’re using multiple rolls, stagger the seams and secure them with outdoor-rated tape or adhesive.

For added stability, especially on hard surfaces, you can use turf pins or glue around the edges. Make sure any drainage holes face downward and align with the slope if present. Once the underlay is in place, walk over it to press it flat before laying your turf.

Common Mistakes to Avoid

• Skipping base preparation. Uneven or soft ground will lead to bumps and sagging.
• Using the wrong underlay for your surface. Foam may slip on decking; rubber may retain heat on open concrete.
• Blocking drainage. Avoid sealing edges too tightly or flattening holes during turf installation.
• Not securing the underlay. Loose padding shifts over time and creates visible ridges.

Take your time with each step. A few extra minutes during installation can save years of frustration later.

Can You Glue Artificial Grass to the Underlay?

Yes, you can glue artificial grass to the underlay—but it’s not always necessary. Whether or not you should depend on the type of underlay, the base surface, and how permanent you want the installation to be.

On hard surfaces like concrete or paving, adhesive is often used to secure both the underlay to the base and the grass to the underlay. This helps prevent shifting, especially in areas with heavy foot traffic or extreme weather changes. Make sure to use outdoor-grade adhesive that works with foam, rubber, or whatever material your underlay is made from.

That said, gluing is not always the best solution. On soil or decking, full adhesion can block drainage or trap moisture. In these cases, securing the turf with U-pins, turf tape, or letting it float with weighted edges might be more practical.

If you’re doing a DIY install, gluing the perimeter only is a common compromise. It helps hold the edges down while still allowing flexibility in the middle. Just avoid sealing the drainage holes or applying glue too thick, which could seep through the turf backing.

In short, glue is an option—but not a rule. Always match your method to the surface and usage scenario.

Artificial Grass Underlay for Drainage: What Works Best?

When it comes to artificial grass underlay, drainage isn’t optional—it’s essential. If water can’t escape quickly, you’ll end up with soggy turf, mold buildup, and shortened product lifespan. Choosing an underlay with good drainage performance is just as important as picking the right turf.

Look for underlay products that include perforations, grooves, or a mesh-style design to let water pass through. Foam and rubber underlays with built-in drainage channels help direct rainwater down to the sub-base, preventing pooling on the surface. This is especially important in areas with heavy rainfall or poor natural drainage.

But it’s not just about the underlay. A drainage-friendly sub-base—such as crushed granite, limestone chippings, or compacted sand—is also critical. These materials allow water to keep moving down and away from your lawn. Even the best underlay won’t help if it sits on top of dense clay or an uneven concrete slab.

If your yard has no natural slope, consider grading the base slightly to one side or installing a French drain system. It’s a small extra effort that pays off in long-term performance.

Bottom line: always treat underlay and drainage as a system. The best results come from combining a permeable base, a breathable underlay, and turf with a porous backing.

Artificial Grass Underlay for Playgrounds and Kids

If you’re installing artificial grass for a playground, backyard play area, or any space where children will run and fall, the underlay becomes more than just a comfort layer—it becomes a safety feature. A kid-safe turf padding should offer shock absorption, stability, and meet playground safety standards.

The best underlay for these environments is usually a shock pad system made from high-density foam or rubber. These pads are designed to absorb impact and reduce injury risk from trips, tumbles, and falls. Look for products rated for Critical Fall Height (CFH) compliance—an industry standard used in schools and public play spaces.

In most cases, a 25mm to 50mm underlay is used depending on the height of play equipment. Thicker doesn’t always mean safer, though—it has to be properly matched with the turf and tested as a system. Some products come pre-tested and certified when installed with specific artificial grass types.

Besides impact protection, drainage still matters. Kids play in all weather, and standing water creates a slipping hazard. Choose an underlay with perforations or a breathable design that lets water pass through and dry out quickly.

If safety is your top priority, don’t cut corners. Ask the supplier for test reports, especially if the area is for toddlers or will include climbing frames. The right underlay can make a big difference in both peace of mind and actual protection.

Is There a Difference Between Turf Underlay and Padding?

You might hear the terms “turf underlay” and “padding” used interchangeably when discussing artificial grass installations. In most cases, they refer to similar materials—but not always the same function.

Turf underlay is a general term for any layer installed between the base and the artificial grass. It can be made of foam, rubber, or other materials, and serves multiple purposes: leveling the surface, supporting drainage, and adding cushioning.

Padding, on the other hand, usually refers more specifically to the shock-absorbing aspect of the underlay. It’s often used in contexts where impact protection is critical—like playgrounds, sports fields, or rooftops. In those cases, you may see products marketed as “shock pads” rather than just underlay.

In everyday usage, the terms often overlap, especially in residential landscaping. What matters more than the label is the performance—check the material thickness, drainage design, and density to decide if it meets your project’s needs.

So yes, there’s a difference in emphasis. Underlay focuses on the layering function, while padding highlights the cushioning function. In many installations, a single product does both—but not always equally well.

How to Choose the Right Underlay for Your Needs?

Choosing the right artificial grass underlay depends on three key factors: your budget, how the space will be used, and whether you’re installing it yourself or hiring help. Here’s how to decide quickly and confidently.

Balance Budget and Performance

If you’re on a tight budget, start with a basic foam underlay around 10mm thick. It offers decent comfort and is easy to work with. For high-performance needs, such as playgrounds or sports turf, invest in certified shock pads—even if they cost more.

Match the Use Case

Not every area needs the same support. Patios and balconies need drainage-focused underlay. Kids’ play areas need cushioning. Pet zones benefit from antimicrobial and odor-resistant options. Think about who’s using the space—and how.

DIY or Professional Installation

Doing it yourself? Choose underlay that’s lightweight, easy to cut, and doesn’t require adhesives. For professional installs, heavier rubber or multi-layer systems can give better results—but may need expert handling.

Sustainable and Eco-Friendly Underlay Solutions

Eco-friendly artificial grass underlay is typically made from recycled foam, rubber, or mixed polymer materials. These options reduce landfill waste and carbon footprint while still offering essential features like drainage and light cushioning.

While performance may vary slightly between batches, many recycled underlays now match standard foam in durability and softness. They’re a smart choice for residential lawns, especially when paired with permeable turf.

When choosing a green solution, ask suppliers about post-consumer content, recyclability, and safety certifications. You don’t have to trade performance for sustainability anymore—just pick carefully.

Can I Reuse Old Underlay When Replacing Turf?

You can reuse the old underlay if it’s in good condition—flat, undamaged, and still elastic. Check for mold, compression, or tears before reusing. If any part looks degraded, it’s best to replace it to avoid long-term issues.

Final Tips Before Buying Artificial Grass Underlay

Before you buy artificial grass underlay, take a moment to double-check a few essentials. A smart purchase avoids rework and ensures your turf performs as expected.

• Know your base surface. Concrete, soil, and decking need different support and drainage.
• Check product specs. Look for thickness, material type, drainage design, and usage rating.
• Ask for a sample. Feeling the material helps judge softness, density, and flexibility.
• Plan the full system. Consider how your base, underlay, turf, and edging will work together—not just as separate parts.

Spending five extra minutes checking details now can save five hours of regret later.