Description
1/2 Inch Screening is a mid-size screened stone, about 13mm (half an inch is 12.7mm). The imperial name is still common in the trade.
It sits between the fine toppings, such as Topping 7mm, and the 20mm stones in the range, for drainage work that calls for something coarser than a topping but smaller than 20mm.
It is a clean, single-size stone: the fines have been screened out, so it drains freely and stays loose. For a compacted surface, use Crush Rock 20mm instead.
For drainage, the smaller stone packs more closely around a pipe than 20mm stone while still leaving open voids for water.
Technical Specifications
| Material | Screened rock |
|---|---|
| Size | 1/2 inch (about 13mm) |
| Application | Drainage, general construction |
| Sold as | Loose, by the cubic metre in quarter-m3 steps |
| Collection | Pickup from Keilor East, Melbourne |
Where to Use
- Drainage applications
- General construction work needing a mid-grade screening
- Backfill around agricultural pipe and soakage pits
How to Apply
- Prepare the base – clear and level the area before spreading.
- Spread to the required depth – distribute evenly across the drainage or construction area.
- Settle the layer – rake level; for a load-bearing compacted base use a crushed rock with fines instead.
- Grade for drainage – ensure adequate fall where used in a drainage application.
- Top up as needed – replenish over time as material settles or is displaced.
Important Notes
- Sized at about 13mm (half an inch is 12.7mm); a single-size screening without fines, so it stays free-draining rather than compacting hard.
- A mid-grade screening between fine toppings and coarser crush rock.
- 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.
- Crushed stone contains crystalline silica: keep it damp when spreading or sweeping, avoid breathing the dust, and wear a P2 mask if it is dry and dusty.
- Roughly 1.4 to 1.5 tonnes per cubic metre.
- Further reading: Construction aggregate (Wikipedia).
