*Last updated: October 2020
Frequently Asked Questions
- What is a roller?
- What are rollers used for?
- Why should I compact soil?
- How do rollers work?
- What are the types of rollers available?
- How can I hire a roller?
What is a roller?
A roller compactor is a piece of machinery that is used to densify (compact) materials like soil, sand, and clean fill, usually undertaken within a major project.
Roller compactors reduce the size of soil and other material by using static force with hydraulics. There are a number of rollers available for hire around the country, where these machines are one of the most common pieces of equipment used on sites across Australia.
Rollers are one of our most popular machines and are used for compaction and to evenly smooth surface materials. While these machines are usually used for road works jobs, they’re also used for agricultural and landfill purposes, and compact concrete, gravel, asphalt and soil into a perfectly flat foundation, allowing the final surface to be laid accurately and precisely. Generally, rollers have a few basic features regardless of the type, including a drum, which can be a smooth, static drum or a vibratory drum, a compaction metre, a water system, tyres, and protection for the driver.
It’s important to understand the distinction between a roller and a flat plate compactor, as they are both often referred to as compactors. Where the latter is a wheel-less, walk-behind piece of equipment around the size of a typical lawn mower that is often used on smaller construction projects.
Our directory offers a huge volume of qualified roller compactor hire suppliers throughout Australia, with both wet and dry hire options available. These suppliers offer a diverse catalogue of roller types and sizes to suit a variety of projects and operations across the nation.
What are rollers used for?
Rollers are primarily used to create compact foundations for a range of construction jobs and projects. While these machines are usually used for road works jobs, they’re also used for agricultural and landfill purposes, as well as to compact concrete, gravel, asphalt and soil into a perfectly flat foundation, allowing the final surface to be laid accurately and precisely.
Generally, rollers have a few basic features regardless of the type, including a drum, which can be a smooth, static drum or a vibratory drum, a compaction metre, a water system, tyres, and protection for the driver.
One of their most prominent benefits is the ability to increase the load-bearing capacity of a surface. As a result, these machines have become a vital element in projects like road works, construction and even mining, where they are used to compact soil before bitumen or concrete is poured or to vehicle risks on mine sites.
Vibration models are most popular for use in densifying granular soils, while static roller models are popular for use on cohesive and clay soils where a vibration method may in fact hinder compaction efforts.
Why should I compact soil?
By compacting soil, the ground becomes more stable, more resistant to penetration by tree roots, water and flooding, and can typically handle more surface weight without erosion occurring. If you’ve ever seen an old footpath square that’s sunken or buckled down it’s likely due to the soil underneath it eroding or shifting as a result of penetrating water or the emergence of new tree roots.
How do rollers work?
There are two ways a roller works depending on the main build, being either static or dynamic. Vibratory rollers (also called dynamic rollers) use a combination of weight and vibration, while static rollers use static weight without the use of vibrations or hydraulics.
Static rollers lack a hydraulic system and vibratory-inducing mechanisms, where they instead gain their compacting capability from raw weight and the practice of oscillation, with the use of hexpad, sheepsfoot or tamper-type drum wheels. Static rollers are ideal for use on cohesive and clay soils where a vibration method may in fact hinder compaction efforts. For granular soils, like gravel and sand, it’s suggested to use a static roller with hexpad or tamper-type wheels.
A vibratory dynamic roller (the more common variant) undertakes oscillation (moving back and forth) with the application of weight and vibration (static and dynamic forces) to increase soil density and strengthen the load-bearing capacity of a surface. To achieve this, rolling compactors use a drum (or drums) to transmit compaction forces, created by vibration-inducing mechanisms, to surfaces that it passes over.
Essentially, dynamic rollers use a combination of pressure, force via weight, and vibration-inducing mechanisms while oscillating (moving back and forth) over a surface. This process in turn enables the roller to effectively squash soil, landfill, and related surface materials down (compacting them), removing air voids and in turn enabling the original volume of mass to be reduced, increasing density and surface load-bearing capacity. In technical terms, the drum’s static weight delivers a compacting force which is augmented by induced vibrations. Vibration-inducing mechanisms produce high cyclic forces that enable the drum to power through any frictional or cohesive resistance presented by surface material.
What are the types of rollers available?
A three point roller is a static roller that uses its mass weight with oscillation to deliver surface compaction. These static compaction rollers are commonly used on granular, semi-cohesive, cohesive, asphalt and clay soil surfaces, as well as in situations where a vibration method may in fact hinder compaction efforts or may be inappropriate (like on bridges).
Multi tyre rollers, like the Caterpillar CW34 and CW12, are available as either static or dynamic (vibrating). The dynamic variants (that utilise dynamic kneading) are ideal for use on hot mix asphalt and aggregate base, as well as warm and cold mixes. Static multi tyred rollers utilise pneumatic tyres that make it ideal for use in surfacing and sealing efforts. Static variants are used for proof rolling, cement stabilised soils and asphalts, and for the final dressing on road works. The pneumatic tyres are specifically designed for the compaction of asphalt mixes, soil bases and subbases.
Padfoot rollers (or sheepsfoot rollers), like the Caterpillar CP533E and CP44B, are dynamic compaction machines that utilise a unique padded drum wheel and vibrating mechanisms. Their main feature is their padfoot front drum wheel, which has a unique padded tread design. These legends have become increasingly popular over the years due to their versatility in regard to project application. Padfoot rollers are used on a wide range of project types where they work on almost all types of semi cohesive and cohesive soils and clay.
Smooth drum rollers, like the Caterpillar CB16 and CB8, are primed for use on non-cohesive (granular) soils like gravel, sand, and mixed soils. Unlike the rugged bumpy drum of a padfoot roller, a smooth drum roller uses a smooth tread on its drum wheel. These compaction rollers are the most common type of roller to rent and have played an important role in the construction and upgrades of roadways across Australia.
Landfill Compactors are typically big guys, like the CAT 836K, that are primarily used for landfill and waste compaction on major project sites across Australia. You are unlikely to find one of these on an inner-city house project.
Pneumatic Rollers (generally static multi tyred rollers), like the Caterpillar CW34, are often used on cold mix, sub-grade soil, or granular material increase density and identify weak areas so that they can be repaired before paving takes place. Additionally, they are used on hot mix asphalt in the initial breakdown as well as the intermediate phases in order to increase density and seal the surface of the mat.
Tandem Vibratory Rollers (or Drum Utility Rollers) are ride-on open-air compactors, like the Caterpillar CB1-7, are popular machines often seen on roadwork projects across the nation. The standard compaction width on these compactors range from 900mm to 2130mm.
If you’re not quite sure which type of roller is right for your job, our projects team can listen to your project requirements and let you know where to find reliable equipment that offers excellent value and the piece of mind that it will get the job done - both safely and efficiently.
How can I hire a roller?
If you’re looking for expert advice about the best roller compactor to hire for your next project, get in touch with iSeekplant or check out supplier listings on our website. Through our listings, you can easily browse a variety of different roller hire suppliers to find the best machine and rates available. Be it a vibratory roller or dynamic roller, our suppliers will have you covered. Use the search bar at the top of this page to find machines and to get rates for rolling compactors in your area! If you'd like to do some more reading before making a decision read our price guide on roller hire rates.
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