Description
Scoria 20mm is a lightweight, porous red volcanic rock used for drainage layers and as decorative garden bed cover. The air pockets in the rock make it noticeably lighter than solid crushed rock of the same size.
As a drainage layer, the open spaces between the stones let water move through freely; give a drainage trench enough fall to an outlet. As bed cover it gives a strong red colour. The colour is the rock’s natural mineral colour, so there is no dye to fade, though it may dull with dirt and weathering.
It sits alongside the finer Scoria 7mm: choose 20mm for larger beds and drainage runs, and 7mm for pots and detail work.
Technical Specifications
| Material | Porous red volcanic scoria |
|---|---|
| Size | 20mm |
| Application | Drainage, decorative garden cover |
| Sold as | Loose, by the cubic metre in quarter-m3 steps |
| Collection | Pickup from Keilor East, Melbourne |
Where to Use
- Drainage layers and drainage applications
- Decorative garden bed cover
- Larger garden beds and drainage runs (20mm grade)
How to Apply
- Prepare the base – clear the area and lay a weed mat for garden bed use.
- Spread to an even depth – distribute evenly for decorative cover, or to the required depth for drainage.
- Grade for drainage – where used in a drainage application, ensure adequate fall.
- Define edges – edging keeps decorative scoria contained against lawn or garden beds.
- Top up as needed – replenish over time as material settles or is displaced.
Important Notes
- Naturally porous and lighter by volume than solid crushed rock of the same size.
- Natural mineral colour, so there is no dye to fade; it may dull with dirt and weathering.
- Pickup from Keilor East (Melbourne). Sold loose by the cubic metre in quarter-m3 steps; part loads of a quarter, half and three-quarter cubic metre are available.
- Roughly 0.8 to 1 tonne per cubic metre, about half the weight of solid crushed rock.
- Crushed stone dust can contain crystalline silica. Keep the material damp when spreading or sweeping, avoid breathing the dust, and wear a P2 mask if it is dry and dusty.
- Further reading: Scoria (Wikipedia).
