A contractor emails us photos eight weeks after handover: a ripple across the middle of a lawn and water sitting at one corner. The roll performed exactly as specified. The layer under it moved, and the surface copied every dip.
Green yarn hides a weak layer for weeks, which is why base materials matter more than most specification sheets admit. We build rolls for contractors, distributors and landscape buyers, and the same three failures reach our bench again and again: wrong gradation, thin compaction, no verified fall.
What the Base Does Under a Turf Roll
A tidy artificial turf installation starts with a layer nobody photographs. That layer carries load, passes water downward, resists settlement and holds a plane for seams to sit flat against.
Stated another way, why base materials matter is not philosophy. A base that drains, locks and stays level buys years of service from the carpet above. One that fails any of those three sends its defect pattern upward within a season.
Buyers who write those three jobs into a subcontract document spend far less time arguing about blame later. Measurements replace adjectives, and the conversation moves from opinion to evidence.
Choosing Aggregate Base Materials That Hold Shape
Start from particle shape, not from the cheapest local ticket. Angular particles interlock under load; rounded ones roll. Most yards stock some version of 3/4 inch minus crushed stone or Class II road base, and those two names cover the majority of jobs.
| Material | What it gives | Where it fits | Watch out |
|---|---|---|---|
| Crushed stone with fines | Interlock plus high permeability | Default for lawns, commercial areas and fields | Needs thin lifts and moisture to reach density |
| Class II road base | Predictable gradation batch to batch | Municipal and contractor bids | Confirm the regional equivalent name |
| Decomposed granite | Smooth finish, tight surface | Dry regions and final fine grading | Holds moisture in wet climates |
| Coarse sand | A leveling pass only | Top screed under the carpet | Never used as the structural layer |
| Recycled concrete aggregate | Lower embodied impact | Large commercial areas | Must arrive clean and well graded |
In commercial artificial turf installations, traffic decides the material before drainage does. Rounded stone cannot lock, so pea gravel belongs inside French drains and decorative borders rather than under a wearing surface.