Say Yes to Natural Grass

What Is a Sand-Capped Athletic Field System?

The Crocker Amazon baseball fields are built on native soil. After heavy rain it can take a day or two to be playable. Athletic fields constructed with a sand-capped system are practical and cost-effective and transform a native soil field into a stable, sand-based playing surface — without the price tag and the plastic.

How the System Works

The system has drain tiles and a sand-based root zone. The construction process involves two core elements:

Drain Tile Installation: Drains are cut lengthwise into the existing field on 6–20 foot centers depending on surface grade and slope. Drain tiles are placed in the lines, and the lines are backfilled with pea stone and then sand, or coarse sand alone.

Repeated Sand Topdressing: An aggressive sand-based topdressing program is then conducted during the summer using approximately 90% well-graded sand. The goal is to add at least 2 inches of topdressing as fast as possible without compromising fall playing quality, meaning the program runs from early June through early August. The topdressing is paired with routine field maintenance like inter-seeding, fertilization, and cultivation.

The sand material itself is important. It should be well-graded — with particles distributed across a range of sizes — containing approximately 90% sand and 10% silt and clay, to optimize stability and drainage.

Advantages of the Sand-Capped System

Dramatically Lower Cost
The Built-Up Sand-Capped System can be completed for approximately $58,200–$103,800 (including irrigation system installation, drain tile, and sand topdressing), compared to $600,000–$1,000,000 for a synthetic field. The land does not have to be excavated 8 feet deep, destroying roots of nearby trees.

Field Stays in Play
Unlike other renovation methods, this process does not remove existing turf but rather amends it, so the field is never totally taken out of play.

Improved Drainage and Surface Stability
As little as ½ inch of cumulative topdressing sand will substantially decrease surface soil moisture and improve surface stability. Greater sand depths further improve drainage and provide a deeper, non-restrictive rooting medium.

Standing Water Eliminated Even in Year One
During the first year, when the root zone may not yet be deep enough to prevent all saturated surface conditions — particularly in low-lying areas — the drain tiles will prevent standing water from developing, providing conditions better than the original field.

End Result Comparable to Artificial Turf
After drain tile installation and sequential top-dressing applications, the goal is to develop a 2-inch, sand-based profile over time — producing a well-drained, stable field at a fraction of the cost of other renovation approaches.

Proven Track Record
The feasibility of the system is not in question — the technique of building a sand-based profile through repeated topdressing has been used successfully on golf course putting greens for over 30 years, and sand-based athletic fields have long been proven to provide superior playing surfaces compared to native soil fields.

Tell the SF Rec & Park Commission and your Supervisor about the kind of park you want.