What is the Best Base for Artificial Turf? Materials, Depth & Tips

The best base for artificial turf is Class II road base, also called crushed miscellaneous base or CMB, compacted 3 to 4 inches deep. It drains well, compacts into a stable surface, and costs less than most alternatives. Decomposed granite is the next best option, especially in drier climates or pet areas where drainage matters most.

Even the best synthetic grass on the market will shift, sink, or drain poorly if the ground underneath isn’t right. Here’s what actually goes into a proper base, how deep to dig, and how to avoid the mistakes that ruin most DIY installs.

Why the Base Matters More Than the Turf Itself

You can buy the best artificial grass available and still end up with a bad lawn if the foundation underneath is wrong. The base is doing four jobs at once.

Drainage: Water needs somewhere to go. A compacted base lets it pass through instead of pooling on top.

Stability: A solid base keeps the turf from shifting, sinking, or developing low spots where people walk most.

Leveling: This is what gives you a flat, even surface instead of a lumpy one.

Weed control: A properly built base, paired with a weed barrier, cuts down on growth pushing up from the soil below. Keep in mind a weed barrier only blocks growth from underneath. Weeds can still take root from seeds or debris that land on top of the turf, so occasional surface cleaning still matters.

Best Base Materials for Artificial Turf

Class II Road Base (CMB)

This is a mix of crushed rock, gravel, and fine particles that compacts into a dense, stable surface. It’s the same material used under actual roads, which tells you something about how well it holds up. It drains well, it’s budget-friendly, and it’s the standard choice for most residential artificial grass installs.

Decomposed Granite (DG)

DG compacts into a smooth, permeable surface with excellent drainage. It costs more than CMB, but it’s worth the upgrade for pet areas since it drains liquid fast and resists holding odor. It’s also a strong choice in dry, arid climates where soil is already sandy or loose.

CMB or DG: Which One to Pick

Go with CMB for most yards, walkways, and general backyard use. It’s the better all-purpose option for stability, drainage, and value.

Choose DG if you have dogs, live somewhere hot and dry, or want the cleanest possible drainage performance. For sports areas or anywhere with heavy foot traffic, use CMB and add a shock pad underneath for cushioning.

Your existing soil matters too. Heavy clay, poor natural drainage, or major grade changes on the property may call for extra prep before either material goes down.

How Deep Should the Base Be?

Depth depends on how the area gets used.

Residential lawns and walkways need 3 to 4 inches of compacted base.
Pet areas need 3 to 4 inches, with DG preferred for drainage and odor control.
Putting greens need 4 to 6 inches minimum, sometimes more with a specialized base system.
High-traffic or sports areas need 4 to 6 inches, compacted in layers, sometimes with a shock pad added.

One thing that trips people up: these numbers are the finished, compacted depth, not the raw excavation depth. Base material settles as it compacts, so you need to account for that settling when you dig, not just measure the hole and fill it once. If your soil is heavy clay or drains poorly to begin with, go a little deeper than these minimums. It’s cheaper to add an extra inch of base now than to fix a soggy lawn later.

What Goes Under Artificial Turf

A correctly built base has four parts.

Subgrade. This is your native soil, excavated, cleared of debris, and graded properly before anything else goes down. It should be firm and free of soft spots.

Weed barrier fabric. A permeable landscape fabric goes down next, like 3×50 weed barrier for smaller yards or the 6×300 roll for bigger jobs. It blocks weed growth from below while still letting water pass through. This step gets skipped constantly on DIY jobs and it’s a common reason weeds show up through turf a year later.

Aggregate base. This is your CMB or DG, spread and compacted in the depth ranges above. Aim for roughly 70 percent solid material to 30 percent fine particles for the best compaction.

Leveling layer and infill. A fine leveling material may be used for final adjustments before the turf goes down. Once the turf is rolled out and secured, infill gets brushed into the fibers. Silica sand is standard for residential lawns. CamoFill is a step up for added cushioning, and Zeodorizer is worth adding in pet areas since it’s built specifically for odor control.

Step-by-Step: Preparing the Base

Clear the area: Remove existing grass, roots, rocks, and debris down to bare soil.

Excavate to depth: Dig out enough to account for compacted settling, generally 3 to 4 inches for standard use, deeper for pet areas, putting greens, or sports fields.

Prepare the subgrade: Compact the exposed soil and fix any soft or unstable spots. Build in a slight grade for drainage rather than leaving it perfectly flat.

Lay the weed barrier: Roll out landscape fabric across the area, overlapping seams by a few inches.

Add and compact the base material: Spread your CMB or DG in layers, running a plate compactor over each one before adding the next. For deeper installs, build it up in stages rather than dumping the full depth at once.

Check the grade. Use a level, string line, or screed board to catch high and low spots before moving on.

Roll out the turf. Once the base is compacted and level, your synthetic grass is ready to go down, whether that’s installing turf on dirt or over an existing hardscape.

This is step 2 of Festival Turf’s full install sequence. See the complete DIY installation guide for what comes before and after base prep.

If you want to see how a properly finished install looks and feels before committing to a full order, request free samples shipped straight to your door.

Tools You’ll Need

Base prep doesn’t take specialized equipment, just the right basics and a willingness to do some digging.

Shovel and rake
Wheelbarrow
Plate compactor, for compacting each layer
Level, string line, and screed board
Landscape fabric
Hand tamper, for small areas
Nails, for securing edges, like 40d5 nails or 5.5″ EG nails
Work gloves and sturdy footwear

Of everything on this list, the plate compactor matters most. Skimping here or renting a weak one is the fastest way to end up with a base that looks fine on install day and sinks within a season.

Common Base Mistakes That Ruin Artificial Turf

Skipping proper excavation. Installing turf directly over existing grass or an uneven surface leads to settling and an uneven finished lawn.

Using too little base material. A shallow base won’t hold up, especially in high-traffic spots.

Failing to compact each layer. Spreading aggregate and calling it done isn’t enough. Every layer needs its own pass with the compactor.

Ignoring drainage. Your base should have a slight grade, roughly 1 to 2 percent, so water has somewhere to go instead of pooling in the middle of the yard.

Leaving high and low spots unchecked. Small imperfections in the base get much more noticeable once the turf goes down.

Treating the base as an afterthought. The turf is the part everyone sees, but the base is what determines how long the whole system holds up. Time spent here saves money later.

DIY or Hire a Pro?

Small, flat, easy-access areas are reasonable DIY projects if you have a plate compactor and are comfortable with excavation and compaction work.

Professional installation is usually the better call for larger or more complicated jobs, especially with poor drainage, heavy clay soil, significant slopes, or difficult equipment access. A professional can evaluate the site, determine the right depth, and make sure everything is properly graded and compacted.

Festival Turf supplies the artificial grass and base materials. We don’t handle installation directly, but we can help you pick the right product for your project and point you toward trusted local installers.

FAQ

What is the best base for artificial turf?

Class II road base, also called CMB, is the best all-around base for artificial turf. It compacts well, drains properly, and costs less than most alternatives. Decomposed granite is a strong second choice, especially for pet areas or dry climates.

How deep should the base be for artificial turf?

Most residential installs need 3 to 4 inches of compacted base. Putting greens and high-traffic or sports areas need 4 to 6 inches for a firmer, more durable surface. These numbers refer to the finished, compacted depth, not the raw excavation depth.

Is CMB or DG better for artificial turf?

CMB is the better all-purpose option for most residential projects. DG is worth the extra cost when drainage is the top priority, particularly for pet areas or dry climates with loose, sandy soil.

Do I need a weed barrier under artificial turf?

Yes, a permeable landscape fabric between your soil and base material blocks weed growth from below while still letting water drain through. It won’t stop weeds from seeds or debris that land on top of the turf, so occasional surface cleaning still helps.

Can I install artificial turf without a base?

No turf installed directly on soil or existing grass will develop uneven spots, drain poorly, and wear out much faster. The base is what keeps your turf flat, stable, and properly drained for years.

What is infill and do I need it?

Infill is the material brushed into the turf fibers after installation. It helps blades stand upright, adds cushioning, and keeps the turf weighted down. Silica sand works for most residential lawns, while CamoFill or Zeodorizer add extra cushioning or odor control for pet areas.

The Foundation Decides Everything Else

A good base is what separates artificial turf that looks great for fifteen years from turf that needs to be redone in two. Use Class II road base or decomposed granite, dig to the right depth for your use case, don’t skip the weed barrier, and compact every layer separately.

Every Festival Turf product comes backed by a 15-year warranty, so once your base is done right, your turf is built to last. Not sure which product fits your project? Order free samples and feel the difference before you buy.