Crusher dust, also known as scree, is fine rock particle, compacted, which has been excavated and refined.
It comes from the process of crushing rocks and stones to extract aggregates for use in construction, roadwork and quarries. It's also used in landscape gardening and farming. A prime example would be adding it to topsoil to create highly fertile soil that helps plants grow at a rapid rate. Often you will hear people refer to it as; crushed stone, broken stone or chipped rock (in some cases). It differs from gravel in the sense that gravel can be formed naturally without having been through an artificial processing system like crushing and breaking down large pieces of rock.
Due to its large particle sizes, it can be found in a multitude of applications such as; landscaping/hard landscaping (landscapers use it for borders and pathways) construction (it's used as an additive for concrete or asphalt), manufacturing (filler for water-proofing materials), sports astroturfing and athletics surfaces and much more. Typically trucked in bulk, it can be bought by the loader.
A full load weighing 13 tons is equivalent to about 1 cubic metre which could cover 30 square meters at 10cm deep. The truck will dump it on site using a dumper attachment mounted on the back of the vehicle. It can be applied by hand or via a spreader, such as a rotary dosing machine.
A popular alternative which is becoming more and more common, uses crushed dust instead of pea gravel, for roadwork projects where the road base consists of stone and sand. Due to the small particle sizes the sharp edges and corners of stones are taken out, helping to reduce rock fillers' exposure to hydroplaning as this will prevent water from pooling on an area and build up speed so it can move easily across a flat surface. Hydroplaning happens when rainwater fills in all available spaces on an asphalt surface leaving no room for tires to contact solid material resulting in loss of control as vehicles become unstable due to lack of friction.Crusher dust has a number of all-round applications for almost any civil project. It can be used in topsoil to improve its water retention properties, making it more effective at preventing run-off during heavy rainfall. Compacted rock crushed into pieces can be used to cover turf lawn to add some weight so that the lawn stays in place. This is an alternative to creating an artificial grass environment at your house. The low level of permeability makes crushed dust an ideal foundation for roads and driveways where the removal of surface water is needed without compromising access by vehicles - i.e car-parks, train stations, airports etc... One positive aspect worth noting is that crushed dust can be applied directly onto grassed areas with little or no effect on surrounding plants when trodden in thoroughly enough due to its porous nature. Although not common practice in all scenarios, it can also be used as a drainage medium when filling trenches in road-building projects.
The main product of crushed dust is composed of crushed stone or gravel. Depending on the density needs, extra components may be added to increase total weight and aid compaction (i.e limestone, clay, cement etc...). Often a small amount of water is added to make the crushed dust easier to transport. It can be purchased from any plant hire supplier, landscape garden centre or hardware store.
Crusher dust has many applications within the landscaping and other industries. It's used for all kinds of projects that require a top dressing material to add weight, volume and aesthetics to an area. In some cases, it will be used as a general form of filling instead of sand depending on your requirements. Sports astroturfing is popular with this type of application. You could also go down the route of opting for a more attractive, coloured product which serves the same purpose as crushed dust. Wood chippings provide a more decorative finish compared to traditional quarry products and come in a wider variety of colours, including bark. You can use it for soil, compaction, paving etc.
Customers can purchase or shop crushed dust from most plant hire suppliers, landscape garden centres or hardware stores. If you have a large enough vehicle to transport it yourself then this will save you money. Prices vary greatly depending on supply and demand as well as particle size. A small amount of crusher dust is usually much cheaper than buying sand by the bag. If you require a large quantity then it is usually much cheaper to buy the raw aggregate in bulk (especially if you have your own vehicle).
Crusher dust is cheaper than sand and other fill products such as bark mulch. It's available in various grades depending on your requirements, but tends to be more expensive than garden soil or topsoil. It's still very affordable and well worth the money if you want a smooth, even finish which provides good drainage and weight for your landscaping needs. You can purchase crushed dust for between $18-$40 per cubic metre (approx) from the market. For reference: 1 tonne of stone will produce around 1m3 of material when crushed down.
A simple broom should suffice to spread the crusher dust over the area evenly making sure to sweep out all hollows including low spots. Just remember to sweep in the direction of the topsoil if present. Crushed dust needs to be kept separate from soil or it can cause severe problems with clumping and compaction at a later date.
Crusher dust provides excellent drainage due to its light weight and porous structure. It can be used as a general filling material for low areas within landscaping projects: These low spots regularly collect water which leads to problems including root rot, wet soil and insects around the home.
No, you should avoid wetting crushed dust before compacting it down. If the material is too moist - this is when problems with compaction and clumping can occur. It's important that any moisture content be soaked up by the surrounding soil instead of the crushed dust itself to prevent mixing issues later on which could lead to a potentially hazardous situation.