Do you need to put anything under artificial turf?

Yes, in most cases, you do need to put something under artificial turf. The “something” is usually a compacted base made from crushed stone or decomposed granite, with optional layers like weed barrier, drainage material, or padding depending on the project. That hidden layer is what helps your lawn drain, stay level, feel stable underfoot, and avoid bumps or sinking over time.

A good artificial turf installation is not just about rolling out the grass. The surface you see matters, but the layers underneath do most of the quiet, practical work.

What do you need to put under artificial turf?

For most yards, the main thing under artificial turf is a firm, compacted aggregate base. This base is usually made from crushed rock, class II road base, decomposed granite, or a similar material that can be graded, compacted, and shaped for drainage. It replaces soft soil as the support layer for the turf.

You may also need a weed barrier, edging, drainage help, or a shock pad, but those are not always required. The right setup depends on where the turf is going, how much foot traffic it will get, whether pets will use it, and what kind of surface is already there.

A typical artificial lawn installation may include:

• Excavated soil: Existing grass, roots, and loose soil are removed so the base can sit at the right height.
• Compacted subgrade: The natural ground is firmed up before new material is added.
• Aggregate base: Crushed stone or decomposed granite creates a stable, drainable layer.
• Weed barrier: A fabric layer can help reduce weed growth from below, though it must be used carefully in pet areas.
• Artificial turf: The grass is laid, trimmed, joined, stretched, and secured.
• Infill: Sand, coated sand, or other infill helps blades stand up and adds weight and cushioning.

Think of the base like the foundation under flooring inside your home. You usually do not notice it when it is done right, but you notice very quickly when it is missing or poorly prepared.

The base is the most important layer

The base is the part many homeowners are tempted to skip, especially if the ground already looks flat. I understand the thought. If the soil seems smooth, why not just lay the fake grass over it and save time?

The problem is that soil moves. It gets soft after rain, shifts with freeze and thaw in colder areas, and settles unevenly when people walk across it. Even small dips can show through artificial turf because the turf follows the shape of what is underneath it.

A properly built base helps prevent those problems. It gives your artificial grass a firm, smooth platform and allows water to move through instead of sitting near the surface. In many fake grass installation projects, the base is the difference between a lawn that looks neat for years and one that starts to wrinkle, puddle, or feel lumpy after a season.

The base also helps with the final height. If the turf needs to meet a patio, walkway, driveway, or garden edge, the installer uses the depth of the base to bring the finished grass to the right level. That makes the project look cleaner and reduces trip edges.

How does the material underneath affect drainage?

The material under artificial turf affects drainage by giving water a path to move down and away from the surface. Artificial grass is usually made with small drainage holes in the backing, but those holes only help if the layers below can accept the water.

If turf is placed directly over compacted clay or uneven soil, water may have nowhere to go. That can lead to puddles, odors, muddy edges, or a soft feeling when you step on the lawn. A crushed stone base creates small gaps between particles, and those gaps help water pass through.

Drainage matters even more in these situations:

• Pet areas: Urine needs to rinse through instead of staying trapped near the backing.
• Low spots in the yard: Water naturally collects there, so grading and base work are important.
• Heavy rain areas: The base must handle more water at one time.
• Poor native soil: Clay-heavy soil drains slowly and may need extra preparation.
• Hardscapes nearby: Water should move away from the house, patio, and foundation, not toward them.

In some yards, a standard compacted base is enough. In others, especially where drainage is already a known issue, you may need extra stone, drain tile, a drainage mat, or grading changes. This is where it helps to be honest about your yard before the artificial turf installation begins. If water collects there now, turf alone will not magically solve it.

Weed barrier is useful but not always necessary

Weed barrier fabric can help reduce weeds from growing up through artificial turf, but it is not a cure-all. Most weeds that appear in artificial grass do not come from deep below. They often sprout from seeds that blow into the infill from above.

A weed barrier is most useful when the turf is going over soil and there is a real risk of roots or weeds pushing up from underneath. It can add a layer of separation between the ground and the base or between the base and turf, depending on the installation method.

There are also times when weed barrier may not be the best choice. In pet lawns, fabric can sometimes trap urine odor if liquid does not move through freely or if the fabric holds moisture. For those areas, many installers prefer a drain-friendly base and turf system instead of relying heavily on fabric.

Here is the simple way to think about it:

• Use weed barrier when: The area has active weeds, loose soil, or garden beds nearby.
• Be cautious with weed barrier when: The turf will be a main bathroom area for pets.
• Do not rely on it alone: Good excavation, edging, base compaction, and maintenance still matter.

Weed barrier can be part of a smart setup, but it should not be the only defense.

Padding and shock pads add comfort and safety

A shock pad is a soft layer placed under artificial turf to add cushion. It is common in playgrounds, putting greens, rooftop spaces, and areas where children play. It is not required for every lawn, but it can make the surface more comfortable.

For a simple front yard or decorative side yard, a compacted base and infill may provide enough support. For a play area, though, padding can reduce hardness underfoot and make the surface feel less like compacted gravel below the grass. If fall protection is a concern, you should choose padding made for that specific purpose rather than using random foam or carpet pad.

This is an important point: indoor carpet pad is not a proper substitute. It can hold water, break down outdoors, and create odor problems. Outdoor turf padding is designed to drain and handle weather.

Shock pads may be worth considering for:

• Backyard play zones
• Daycare or school lawns
• Rooftop patios
• Putting greens that need a specific feel
• Areas where comfort matters more than the lowest project cost

If your goal is a basic artificial lawn installation, padding may be optional. If your goal is comfort, play, or impact reduction, it becomes a much more serious part of the plan.

Can artificial turf go over concrete or decking?

Artificial turf can go over concrete, pavers, balconies, and some decking, but the layers underneath are different than they are for soil. You usually do not need a crushed stone base on top of concrete because the hard surface is already stable. Instead, the focus shifts to drainage, cushioning, and secure attachment.

Concrete needs special attention because water can get trapped between the slab and the turf. If the slab is sloped and drains well, installation is usually simpler. If it has low spots, cracks, or poor drainage, those issues should be addressed before the turf goes down.

On hard surfaces, the layer under turf may include:

• A drainage mat to lift the turf slightly and let water move underneath
• Outdoor adhesive or seaming materials approved for turf
• Perimeter fastening where mechanical fastening is possible
• Padding for comfort, especially on balconies or play areas
• Proper edge finishing so the turf does not curl or become a trip hazard

Decking is a little more sensitive. Wood needs airflow so it does not stay damp for long periods. Before putting turf over a deck, make sure the structure is sound, the boards are in good condition, and water can escape.

Common mistakes with what goes under turf

Most artificial turf problems start below the surface. The grass may get blamed, but the real issue is often the base, drainage, or prep work.

Common mistakes include:

• Laying turf directly on soil: This can lead to sinking, wrinkles, weeds, and poor drainage.
• Skipping compaction: Loose base material settles later, creating dips and uneven spots.
• Using the wrong base material: Round gravel can shift too much, while fine material may drain poorly if overused.
• Ignoring slope: Water should move away from buildings and out of the turf area.
• Forgetting edge restraints: Edges need support so the turf stays tight and clean.
• Using indoor materials outside: Carpet pad, indoor adhesive, or non-draining fabrics can cause trouble.
• Assuming infill replaces the base: Infill supports the grass blades from above; it does not stabilize the ground below.

If you are doing a DIY fake grass installation, spend more time planning the base than choosing the exact blade color. Both matter, of course, but the base is harder to fix after everything is installed.

Practical examples of different turf setups

Different projects need different layers. There is no single recipe that fits every yard, but these examples can help you understand what may apply to your home.

• Small decorative front lawn: Usually needs soil removal, compacted aggregate base, turf, edging, and infill. Weed barrier may help if weeds are active.
• Pet relief area: Needs excellent drainage, a stable base, pet-friendly turf, and infill that can be rinsed. Weed fabric should be chosen carefully.
• Children’s play area: May need a compacted base plus outdoor shock pad for comfort and impact support.
• Concrete patio cover: May need cleaning, drainage mat or padding, turf adhesive, and secure edge finishing.
• Putting green: Needs very careful base shaping because small bumps affect ball roll. The base must be smooth, firm, and well compacted.
• Side yard walkway: Needs a strong base and good edging because narrow strips can shift if not secured well.

These examples are not rigid rules. They are starting points. Your soil, climate, slope, and how you plan to use the space should guide the final setup.

A simple checklist before installation

Before you begin an artificial turf installation, walk the area and ask a few practical questions. This step can save you from expensive fixes later.

• Does water currently drain well, or does it puddle after rain?
• Is the soil firm, sandy, clay-heavy, or soft?
• Will pets use the turf often?
• Will children play or fall on this area?
• Does the finished turf need to meet a patio, door threshold, or walkway?
• Are there tree roots, sprinkler heads, or old landscape fabric in the way?
• Do the edges have something solid to hold against?
• Is this a soil installation or a hard-surface installation?

If you are unsure about any of these, slow down before buying materials. The best time to solve drainage, height, and base issues is before the turf is rolled out.

The bottom line

In most cases, artificial turf needs a properly prepared layer underneath it. For soil areas, that usually means excavation, a compacted crushed stone base, and careful grading. For concrete or decks, it may mean drainage matting, padding, adhesive, or other hard-surface details.

The visible grass is only one part of the system. The layers below decide how well the lawn drains, how smooth it feels, and how long it keeps its shape. If you remember one thing from The Flooring Guide, let it be this: do not treat the base as a shortcut. Treat it as the part of the project that protects everything you see on top.

USA Flooring provides professional installation to make sure your investment lasts. Find a location near you to get started!