How does artificial turf drain without added pipes?

How water moves through artificial turf without pipes

Modern turf systems are built to shed water vertically. Rain passes through the turf backing, moves through the infill, then drains into an open-graded stone base that spreads and infiltrates water into the native soil.

1. Perforated turf backing

• Factory-punched holes across the backing allow rapid vertical drainage.
• Perforations are distributed to prevent pooling and to keep surface play consistent.

2. Infill that does not block flow

• Properly graded silica sand or specialty infills sit between fibers and allow water to pass.
• Right infill depth maintains permeability and surface stability.

3. Free-draining stone base

• Open-graded, angular stone creates void space so water can move freely.
• Typical residential depth is 3 to 4 inches. Heavier use areas may need more.
• A compacted, smooth surface supports the turf while preserving drainage paths.

Drainage performance by the numbers

• Turf backing drainage is commonly rated from 30 to 100+ inches per hour. Exact performance depends on product design.
• Base infiltration depends on stone gradation, compaction, and native soil permeability.
• With correct slope and base, surface water typically clears within minutes after normal rain.

Slope and grading that make it work

• Target surface slope: 1 to 2 percent away from structures.
• Minimum functional slope for small areas: 0.5 percent if soils and base drain well.
• Feather transitions at edges so water exits cleanly and does not trap along curbs or borders.

When you might add an underdrain

Most lawns do not need added piping. Consider a drain tile or connection to an approved outlet if:

• Native soil has very poor infiltration, such as heavy clay that stays saturated.
• The site is flat with no practical slope or is boxed in by hardscape.
• There is a high water table, spring activity, or code requirements for managed discharge.
• Roof decks or balconies rely on existing drains and require a drain mat to route water.

Base build best practices

• Excavate organic material and unstable soils until you reach firm subgrade.
• Correct grade at the subgrade first. Do not rely on turf to fix poor slope.
• Use clean, angular stone for the base. Avoid fines-heavy mixes that can clog.
• Compact in thin lifts for stability while preserving permeability.
• Use a nonwoven geotextile separator only where needed to keep fines from migrating up.

Edge details that keep water moving

• Set bender board, concrete mow curb, or paver restraints flush with the finished height so water can exit.
• Leave weep paths through borders adjacent to hardscape for overflow relief.

Pet areas and high-use zones

• Choose infill that stays free draining and supports regular rinsing.
• Rinse and groom routinely to maintain permeability and freshness.
• In tight dog runs on clay soils, a small underdrain can speed recovery after heavy use.

Maintenance that protects drainage

• Broom fibers upright to prevent matting that can slow surface flow.
• Remove leaves and debris so perforations remain clear.
• Top up infill if low spots appear after heavy traffic.

Cold weather and freeze-thaw

• Water drains normally until temperatures drop below freezing.
• A well graded base helps ice melt drain away quickly when temperatures rise.

Environmental note

Direct infiltration reduces runoff, eases storm drain load, and keeps water on site where soils can accept it.

Quick install checklist

• Verify slope plan.
• Excavate and stabilize subgrade.
• Place and compact open-graded stone in lifts.
• Fine grade and roll smooth.
• Install turf, seam, and secure edges.
• Add infill and groom. Confirm water flows off and through as designed.