Why this base works
A compacted, free-draining crushed stone base gives you stability, fast drainage, and a consistently smooth roll. Angular stone interlocks under compaction, resists settlement, and sheds water so the green plays true in wet and dry conditions.
Specs at a glance
- Base depth: 3 to 4 inches of compacted angular crushed stone. Increase to 4 to 6 inches in freeze zones or weak soils.
- Material: 3/8 inch minus or 1/4 inch minus crushed granite or similar hard stone. Avoid pea gravel or round rock.
- Slope: 1 to 2 percent, pitched away from structures.
- Compaction: Plate compact to a firm, uniform surface in 1 to 2 inch lifts.
- Optional separation: Nonwoven geotextile over clay or organic subgrades to keep fines from pumping into the base.
- Edging: Steel, composite bender board, or concrete curbing to retain the base.
Materials that perform
- Base aggregate: Angular crushed stone with fines, such as 3/8 inch minus decomposed granite or crushed granite screenings. Fines help lock the surface when compacted.
- Top layer option: In wet or soft sites, use 2 to 3 inches of 3/4 inch minus base rock topped with 1 inch of 1/4 inch minus screenings for final smoothing.
- Geotextile: A nonwoven separation fabric over native soil can improve stability on clays and prevent base contamination.
Build sequence
- Plan the layout: Choose cup locations and seam orientation. Aim to run seams with the main putt line.
- Excavate: Remove sod and organics to allow for base depth and turf thickness. Shape the subgrade with a 1 to 2 percent slope.
- Stabilize subgrade: Moisten and compact the native soil. Add geotextile if soils are clayey or saturated.
- Place base in lifts: Spread 1 to 2 inch lifts of crushed stone, moisten lightly, then compact with a vibratory plate. Repeat to reach 3 to 4 inches.
- Screed and smooth: Use screed rails and a straightedge to set final grade. Hand lute to remove minor highs and lows.
- Set cups: Core holes and set cups in concrete or stabilized base so the cup lip sits the turf thickness below finished grade.
- Compact final pass: Final plate compaction followed by a roller for a tight, even surface.
- Install turf and infill: Dry-fit, seam, and stretch. Brush, infill to spec, then brush again for a true roll.
Slope and drainage
Keep the finished base at 1 to 2 percent slope. On flat or wet sites, add subsurface drainage such as a French drain or perforated pipe set below the base and daylighted. Always pitch away from foundations, patios, and play areas.
Climate and soil adjustments
- Freeze-thaw regions: Increase base to 4 to 6 inches, prioritize hard, angular stone like granite, and maintain positive slope.
- Heavy clay: Use geotextile under the base and consider adding depth for stiffness.
- High rainfall: Use a cleaner, well-graded aggregate and integrate subdrains at low points.
- Soft or filled soils: Proof-roll and undercut soft spots, then backfill with compacted aggregate.
Common mistakes to avoid
- Using pea gravel or round rock that will not lock under compaction.
- Skipping slope or relying on the turf to handle drainage.
- Overlooking edge restraint, which leads to base raveling and turf creep.
- Compacting only the top instead of compacting each lift.
- Setting cups too high or too low relative to finished turf height.
Pro tips for a truer roll
- Screed with fixed rails to keep grade tight within 1/8 inch across the surface.
- Lightly mist the base before compaction to improve density without washing fines.
- Use a 10 foot straightedge to check for birdbaths or humps and correct before turf goes down.
- After infill, cross-brush fibers and make a final pass with a greens roller if desired.
Ready for a no-drama install
Want it built right the first time? Find a FusionTurf installer who lives this spec and delivers smooth, fast greens.
