The base for artificial turf is the part nobody sees and the part that decides how the lawn performs. A properly graded and compacted aggregate base keeps turf flat, drains water and resists settling for years. If you want turf installed on a professional base, it helps to know what the materials are and how they are put down.
What a base for artificial turf does
A sub base for artificial turf has three jobs: carry weight without deforming, move water away from the backing, and give a smooth plane so the turf lies without lumps. Native soil cannot do all three, which is why installers excavate and replace it with aggregate.
Angular crushed rock interlocks when compacted. Rounded gravel such as pea gravel rolls under load and never really locks, so it is a poor choice on its own.
Comparing the common base materials
When people ask what is the best base for artificial turf, the honest answer is that it depends on soil, drainage and use. These are the materials installers reach for most often:
| Material | Description | Strengths | Limitations |
|---|---|---|---|
| Class 2 road base | Crushed rock graded from about 3/4 inch down to fines | Compacts very firm and stable; widely available | Fines slow drainage; may need adjustment for pet areas or clay |
| Decomposed granite (DG) | Weathered granite in small particles | Smooth, easy to screed; excellent top layer | Too fine to serve as a full-depth base on its own in most cases |
| Crushed rock (3/8 or 1/4 inch minus, or clean chip) | Angular crushed stone, with or without fines | Clean versions drain fast; good for dog runs and wet sites | Clean rock needs a fine top layer and edge restraint to stay put |
| Paver base | Crushed aggregate sold for patio and paver projects | Similar to road base; convenient in smaller bagged quantities | Grading varies by supplier; check fines content |
Product names and gradings vary regionally. Our page on class 2 road base goes into that material in more detail.
Road base for artificial turf vs decomposed granite
Decomposed granite alone
- Smooth finish and easy to level
- Fine particles can migrate or wash out
- Softer under heavy or repeated loads
- Best as a finishing layer
Road base with a DG or fine top layer
- Firm structural layer that resists ruts
- Fine top layer gives a smooth plane for the turf
- Standard approach for most residential lawns
- Can be swapped for open crushed rock where drainage is the priority
Decomposed granite for turf installation shines as the final half inch to inch on top of a structural layer, where it fills small voids and lets installers screed a perfectly smooth surface.
Talk to an installer who builds it right
Experienced local crews. Every line item in writing.
How installers build the base
- ExcavateRemove sod and soil to roughly 3 to 4 inches below finished grade, deeper for clay soil, heavy traffic or drainage problems.
- Prepare the subgradeGrade for a gentle slope away from structures and compact the native soil. Add geotextile fabric where soil and aggregate need to stay separated.
- Place aggregate in liftsSpread the base an inch or two at a time, moisten lightly and compact each lift with a plate compactor or roller.
- Finish and checkAdd a fine top layer, screed it smooth, compact again and check the surface for low spots with a straightedge and a hose test.
Pro tip: seams are only as good as what is under them. A base with a small dip will show through as a seam that separates or a line that catches the light, which is why careful leveling matters before artificial grass seams are glued.
Choose a crew that takes base work seriously
Two installs with identical turf can perform very differently because of what is underneath. When you compare installers, ask what aggregate they use, how deep they excavate and how they compact. Experienced crews will have clear answers. Start your project with professional turf installation from a vetted local installer.
Base for artificial turf FAQ
How thick should the sub base for artificial turf be?
Most residential installs use about 3 to 4 inches of compacted aggregate. Poor-draining soil, heavy use or sports applications may call for more.
Can I use paver base for artificial turf?
Often yes. Many paver base products are crushed aggregate similar to road base. Check the grading and fines content, and compact it in lifts.
Is road base for artificial turf good for dogs?
It can be, but dense road base drains slowly. Many pet installs use a more open crushed rock so urine passes through quickly, combined with a perforated or fully permeable backing.
Do I need a weed barrier under the base?
It is often recommended over native soil to separate soil from aggregate and slow weed growth, though a well-compacted base and turf backing already block most weeds.
The complete turf installation guide
What a quality install looks like, the eight installation steps, spec sheets, and how to choose an installer.