Application guide
Pebbles for Drainage
Drainage stone works by holding open void space that water can travel through. Get the grade wrong and the voids fill with silt; get the separation wrong and soil washes in from the sides.
Every reliable drainage detail has the same two elements: appropriately graded clean stone, and a geotextile between the stone and the surrounding soil.
Suitable pebble types
- Drainage pebbles
- Stone chips
- Natural river pebbles
- Water filtration pebbles
Recommended sizes
20–40 mm for French drains; 10–20 mm for shallow planter drainage.
Recommended finish
Natural; washed material performs better and clogs later.
Colour selection
Not relevant — this stone is buried.
Quantity considerations
Trench volume (length × width × depth) or planter base area × layer depth.
Estimate your requirement
Installation tips
- 1Line the trench with geotextile before placing stone.
- 2Bed perforated pipe within the stone, not directly on soil.
- 3Wrap the geotextile over the top of the stone before backfilling.
Maintenance
- Inspect outlets and inspection chambers before the monsoon.
- Replace surface drainage stone if it becomes visibly silted.
Recommended products for drainage
- Drainage PebblesFree-draining stone for planters, French drains, soakaways and terrace build-ups.
- Stone ChipsGraded crushed stone in neutral tones for surfacing, borders and decorative work.
- Natural River PebblesWater-worn stones with a soft matte surface and mixed earthy tones — the everyday workhorse of garden landscaping.
- Water Filtration PebblesWashed, graded stone used as support and filter layers in water treatment systems.
Topic hub
Part of our water feature, aquarium and drainage pebbles guide
Stone selection where water is involved — features, tanks, drainage and filter beds.
Read the water feature, aquarium and drainage pebbles hub →Products in this topic
Where it is used
Drainage — frequently asked questions
Planning a drainage project?
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