Articles · buying & installing

How to install drainage for artificial grass.

Published 10 July 2026

In Singapore's downpours, drainage is what separates a lawn that's dry minutes after a storm from one that pools, smells and lifts. Here's how the base is built, on soil and on hard surfaces, so water runs straight through and away.

Good artificial grass has a perforated backing that lets water fall straight through, so the grass itself rarely floods. The question is what happens next. If the base beneath can't move that water away, it simply sits under the turf. Getting drainage right is almost entirely about the layers you never see.

Cross-section of an artificial grass drainage build-up: sub-base, membrane, drainage cells and turf

Does artificial grass even need drainage?

Yes. The turf drains, but the ground has to as well. On permeable soil the job is to build a free-draining base that lets water percolate down. On hard, non-porous surfaces, tiles, concrete, a waterproofed roof deck, the water has nowhere to soak away, so you create a void beneath the turf and channel it to a drain. Two situations, two builds.

Draining onto soil: the layer cake

Over open ground, drainage is built into a compacted base:

1. Excavate and set a fall. Dig out to depth and grade the sub-grade with a slight slope, about 1 in 100, towards where water should exit.

2. Sub-base. Add and compact a free-draining aggregate (crushed stone / granite). This is the load-bearing, water-moving layer, and the one most DIY jobs skimp on.

3. Blinding layer. A thin course of sharp sand levels the aggregate and gives a smooth bed for the turf.

4. Geo-textile membrane. Rolled over the base to block weeds and stop the layers mixing, while letting water pass.

5. The grass. Laid, tensioned and edge-secured on top. Rain drains through the backing, through the sand and aggregate, and away into the ground.

Draining on decks, balconies and roofs: drainage cells

On a sealed surface there's no soil to soak into, so a compacted aggregate base won't help, water would just sit on the slab. This is where drainage cells come in: interlocking plastic panels that create a continuous air gap under the turf. Water falls through the grass, into the void, and runs across the cells to the existing floor drains or roof outlets, keeping the turf clear of standing water and the waterproofing protected.

Base with sand, geo-textile membrane and drainage cells being laid — 1. Membrane & first cells down

Area fully covered with interlocking drainage cells — 2. Cells cover the whole area

Drainage cells topped with geo-textile and artificial grass — 3. Membrane & turf on top

The turf drains in seconds. Whether your lawn stays dry depends entirely on where that water goes next.

The details that make or break it

Fall. A gentle slope of about 1 in 100 toward the outlet is invisible underfoot but essential, flat ground lets water sit.

Compaction. On soil, an under-compacted sub-base settles unevenly and traps water in the dips.

Perforated backing. Only turf with a properly perforated backing drains freely, some cheap grass has a solid backing that holds water on top.

Clear outlets. On decks and roofs, the drainage cells must actually run to a working drain, and those outlets need to stay clear.

Building a base, or want it built for you?

We supply VersiCell drainage cells, membrane and premium perforated-backing grass, and we install the whole build-up so it drains for good. See the product, or get an exact quote.

Drainage cells How it's installed DIY or pro?

FAQ

Does artificial grass need drainage?

Yes. Quality artificial grass has a perforated backing that lets water through, but the water still needs somewhere to go. A free-draining base, or drainage cells over a hard surface, carries it away so the lawn never pools.

How do you install drainage under artificial grass?

On soil: excavate, set a slight fall, compact a free-draining aggregate sub-base, add a sand blinding, lay geo-textile membrane, then the grass. On tiles, decks or roofs, add interlocking drainage cells above the membrane so water flows beneath the turf to the outlets.

What are drainage cells and when do I need them?

Drainage cells are interlocking plastic panels that create a continuous void under the turf for water to run through. Use them on hard or non-porous surfaces, balconies, roof decks, concrete, where water can't soak into the ground and must be channelled to a drain.

How much fall does artificial grass drainage need?

A gentle fall of roughly 1 in 100 towards the outlet is enough to move surface water. It's invisible underfoot but ensures rain drains away instead of sitting under the lawn.