Under artificial turf you want 3 to 4 inches of crushed rock base, compacted, over excavated soil, with a weed barrier and then infill brushed into the turf on top. In Central Texas that base is usually crushed limestone or decomposed granite. Laying turf straight onto soil is the single most common reason a turf yard fails.
The layers, bottom to top
- Excavated subgrade. The existing lawn and 3 to 4 inches of soil come out. On a pet area we go deeper.
- Weed barrier. Goes down over the subgrade to stop anything pushing up from below.
- Crushed rock base, 3 to 4 inches. Spread, graded to drain, then compacted in passes with a plate compactor. This layer is the whole job.
- Turf. Rolled, allowed to relax, cut to the yard, seamed and glued where pieces meet, then nailed around the perimeter and through the field.
- Infill. Brushed down into the pile so it sits at the base of the blades, not on top of them.
Nothing here is exotic. The difference between a yard that still looks right in year five and one that ripples in year two is almost entirely how well step three was done.
What is the best base to put under artificial turf?
A crushed aggregate with a range of particle sizes, including fines. The fines are what let it lock together under compaction. Uniform rounded gravel will not do this, which is where most DIY jobs go wrong.
| Material | Works? | Notes |
|---|---|---|
| Crushed limestone base (flex base, road base) | Yes | The Central Texas default. Locally quarried, compacts hard, drains well. |
| Decomposed granite | Yes | Compacts tightly and drains. Common alternative here. |
| Class II road base / CMB | Yes | Same idea, regional naming differs. |
| Pea gravel or river rock | No | Rounded and uniform, so it never locks. Turf will shift and dish. |
| Sand as a base layer | No | Migrates and ruts. Sand belongs in the turf as infill, not under it. |
| Native soil, un-excavated | No | Holds water, moves with moisture, grows things. |
Can I lay artificial grass straight on soil?
No, not if you want it to last. Turf laid on soil will settle unevenly, hold water, and let weeds through. It is the fastest way to install turf and the fastest way to have to redo it.
Central Texas soil makes this worse than it is in most places:
- Clay moves. Expansive clay swells when wet and shrinks when dry. A yard laid on bare clay will be visibly lumpy after one wet winter and one dry summer.
- Soil is shallow over limestone. In much of Cedar Park, Round Rock, Leander and Georgetown there are only a few inches of soil over rock. Drainage has nowhere obvious to go, so grade has to be built deliberately. Base depth on those lots is a judgement made in the yard, not from a spec sheet.
- Organic material decomposes. Any turf, roots or thatch left under the turf breaks down and leaves voids. That is what causes soft spots.
The base course solves all three. It is inert, it does not swell, and once compacted it holds a shape.
Can you lay fake grass directly on gravel?
It depends entirely on what kind of gravel and whether it was compacted.
Crushed, angular gravel with fines, properly compacted: that is a base. Yes.
Loose decorative gravel, pea gravel or river rock: no. Rounded stones roll past each other under load. You will feel every footstep and the surface will dish out where people walk.
If you have an existing gravel area you want to turf over, the usual answer is that it needs to be graded, topped with proper base material and compacted first. Occasionally an old compacted driveway base is already suitable. That is a look-at-it-in-person call.
Do you put sand on top of artificial grass?
Yes, but the word “on top” is misleading. Infill goes into the turf, brushed down between the blades so it sits at the backing. It should not be visible as a layer on the surface.
Infill does real work:
- Holds the blades upright so the turf does not lie flat
- Weighs the turf down against expansion and wrinkling
- Protects the backing from UV
- Gives the surface a bit of give underfoot
Common options are rounded silica sand for general landscape use, and a zeolite-based antimicrobial infill for pet areas, which captures ammonia rather than letting it sit. We do not use crumb rubber in residential yards. It is the hottest option in the sun and not what people want their kids on.
Denser turf needs less infill per square foot, because the fibers hold each other up rather than relying on sand to do it. That is part of why a higher face weight partially pays for itself.
Is there artificial grass that doesn’t need infill?
Non-infill products exist, usually very short pile or heavily textured thatch. They are used mostly in small commercial and rooftop settings. For a residential lawn in Texas sun we do not recommend going without infill. It is what stops the blades matting and what keeps the turf lying flat and stable through summer heat.
What should you put down before laying artificial grass?
In order, before the turf goes down:
- Kill and remove the existing lawn. Not just scalp it. Root mass has to come out or it will decompose into voids.
- Deal with irrigation. Cap heads in the turf area. Keep zones that still feed beds and trees. Do not just bury live heads.
- Set the grade. Fall away from the house. If there is a low spot that already ponds, it gets fixed now, not hidden under turf.
- Weed barrier.
- Base, spread and compacted in lifts, then screeded smooth. Compact in passes, not all at once.
- Edging where the turf meets beds or decomposed granite, so the perimeter holds a line.
Turf drains at 30 or more inches of water per hour through the punched backing. Central Texas has never produced rain at that rate, including flash floods. So when a turf yard holds water, the turf is essentially never the cause. It is grade or base. There is more on this in the drainage guide.
Can I install artificial grass myself?
Yes, and people do it successfully, particularly on small flat areas. Be realistic about what it involves: hauling out sod and soil, bringing in base rock by the ton, renting a plate compactor, and cutting and seaming turf that comes on a 15 foot roll and is heavy and awkward.
The failure modes in DIY turf jobs are consistent:
- Not enough excavation, so the turf sits proud of the patio and looks like a rug
- Base compacted in one pass instead of lifts, so it settles unevenly later
- Seams that were not glued and pinned, which separate and become visible
- Not enough infill, so blades lie flat within a season
- No perimeter fixing, so edges lift
None of these show on install day. They show up in year one or two, and by then fixing them means pulling the turf back up, which costs more than doing it once.
Common questions about turf base prep
What is the best base to put under artificial turf?
Three to four inches of crushed angular aggregate with fines, compacted in lifts. In Central Texas that is usually crushed limestone base or decomposed granite. Rounded gravel such as pea gravel does not work because it never locks together.
Can I lay artificial grass straight on soil?
No. Turf laid directly on soil settles unevenly, holds water and lets weeds through. Central Texas clay swells and shrinks with moisture, so a yard laid on bare soil goes lumpy within a year.
Can you lay fake grass directly on gravel?
Only if the gravel is crushed, angular, contains fines and has been compacted. Loose pea gravel or river rock will not hold a shape under foot traffic.
Do you put sand on top of artificial grass?
Infill sand is brushed down into the turf rather than left on top. It holds the blades upright, weighs the turf down and protects the backing. It should not be visible on the surface once it is worked in.
What should you put down before laying artificial grass?
Remove the old lawn and its root mass, cap irrigation in the area, set the grade to drain, lay a weed barrier, then spread and compact three to four inches of crushed base and screed it smooth.
Owner on Site, Foreman on Every Install
We do not subcontract. The people who quote your yard are the people who build the base under it.