Compactor compacting soil | featured image for filling & compacting materials.


Filling and Compacting Materials


If you are looking for some filling material to fill a hole, stabilize some boggy ground or prepare an area for a concrete slab or pavers, Centenary Landscaping Supplies has a complete range to choose from. These products are sourced from a wide variety of quarries and plants in South East Queensland and as with all bulk materials, they are available on site at Darra and can be purchased by the shovel to truck load. To confirm the quantity you need, give the Office a call on 3373 4990 and we will be able to help work out the filling & compacting materials volume required.

Filling and Compacting Products

And what are they used for?

Generally speaking, filling and compacting products refer to bulk material used for filling holes or underneath new concrete or paving. These product are usually not used as a finished surface, but in some cases modified compaction materials can be successfully used for driveways and pathways. Modification means the addition of cement powder to make the finished surface more durable. See below for stabilised materials.

Sourced from the same locations as Road Base, Crusher dust is made up of only the finer material or ‘fines’. Crusher dust, if wet sufficiently, will also compact down hard and give a smooth finished surface. 

One way that both Road Base and Crusher Dust can be made more “durable” is with the addition of cement. This is referred to as “stabalising” and is common practice in areas of high traffic or potential erosion. How much cement is added is up to the individual but generally around 4-8 bags per Tonne of product is the preferred mix ratio.

It is important to note that many paving manufacturers stipulate that crusher dust should NOT be used under their pavers otherwise the warranty will be null and void. Stick to using bedding sand and Roadbase in these situations.

Decomposed Granite is often referred to as “Deco” and in Queensland is usually an orange/brown colour. Deco Granite granules are quite fine (around 3mm or less) and if you imagine the finish on a clay tennis court, then you will have a good idea as to what it the finished product looks like.

Deco can be used as a compacting material but is not as efficient as Roadbase or Crusher dust. Due to this, it is sometimes used as a thin “finishing” layer over the top of a compacted Road Base pathway or driveway to give the preferred natural and more decorative look of Deco. Numerous bush walking tracks around Brisbane use Deco Granite as a finishing layer e.g. Mt Cootha bush trails.

Like both Road Base and Crusher Dust, Deco can also be stabalised with cement. It is recommended a white or off white coloured cement is used, but bear in mind this will alter the finished colour.

Recycled Road Base is a relatively recent invention. With high costs of waste disposal, old concrete products are now recycled through crushing and grading. Larger gravel is graded for drainage applications and finer material is used as fill and base materials. Although these products do not have the strength of their natural crushed rock counterparts, or the same compaction ability, they are definitely a more economical filling and compacting option. 

Typically, Recycled Road Base will have a CBR rating of 15 or more, but can not be guaranteed. It is perfect for general filling applications or under low-use domestic paving. For areas that will handle vehicle traffic, high use spaces or areas subject to high water flow, a CBR45 Road Base is recommended.

Road Base is one of the most versatile filling products we have. It is basically a crushed blue/grey rock around 20mm in size with smaller sized rock particles right down to “fines” mixed in. This blend of sizes enables the product to be compacted down hard. So for a boggy driveway that needs stabilizing or for preparing a hard surface to lay your pavers on, this is the ideal product.

As well as its compactibility, a measure of a Road Base quality is its CBR rating. This stands for the “California Bearing Ratio” and refers to the actual strength of the rock itself. For any area that requires a hard surface, it is important that the rock used does not disintegrate under load (e.g. a car) so we make sure that we supply a roadbase with a CBR of 45 or higher and one that is used extensively by road builders around Brisbane.

Two final notes about the use of roadbase: Firstly, when it is compacted it will reduce in volume, for example, if you compact a 100mm layer it will reduce to between 75-80mm; secondly, to get the best compaction possible, make sure that the material is wet, as this helps all the “fines” bind tightly with the larger stones.

Stabalising refers to the practice of adding cement powder to dry or damp compacting materials rush as Road Base, Crusher Dust or Deco Granite. With the addition of cement, the product can be moistened on-site during the compaction process and give a much firmer or more structural result.

We can pre-mix large volumes of stabalised product in advance for delivery direct to your job site although it is important that this is ordered for delivery to allow for immediate use. The moisture content in these products is often enough for the product to start ‘going off’ or setting hard.

The addition of grey cement is recommended for products such as Road Base and Crusher Dust, but a white or off-white cement will be more effective in Deco Granite. Unfortunately, the addition of cement will alter the original product colour.

Ready to buy? Head on over to our online store and get your next Landscaping Project underway.



Expert advice for a great home & garden!