An excavation job for a garage involves a lot of work if you are doing it on your own.
In case the soil type is not loose sand or clay but composed mainly of solid rock chunks, there are different method to be used for excavation.
There are two types of excavation projects that are commonly performed: trench and rock. When excavating a trench, you can use a backhoe or digger and when excavating the earth out in large chunks, rock excavation is required. In both cases, however, it requires a lot of physical labour with strong muscles to do the excavation. This type of excavation is known as trench excavation and it is done to create a flat surface on which you can build your garage. A backhoe or digger is required for this kind of excavation, however, if they are not available then shovels and pickaxes must be used. The next step after creating a flat surface is to make a level area. Both these types are essential for home improvement projects such as swimming pool excavation, excavating basements, garage excavation and house foundation preparation. They are also important when building on a sloping block or a sloping surface and constructing a standard driveway that can access your garage.
Professional excavators with heavy equipment like electric jackhammers and large-scale hydraulic tools come in handy. These machines help break down the rocks into small pieces which can then be loaded into a dump truck and taken away to a recycling plant.
The time it takes to complete a garage excavation could vary depending on the type of excavation work required. If it is trench excavation, then you can finish this task in as little as two days. If rock excavation has to be done, which is often the case if the terrain is rocky and solid, then it may take up to three weeks. The time taken can also vary greatly depending on other factors like your experience and whether or not you have the right equipment needed for the job at hand. One thing that should be remembered though before embarking on a basement garage excavation, is to check with your local authorities first about obtaining a permit since most Australian states require them before one starts land clearing. This rule applies especially when digging trenches on a property that has power lines and gas lines.
In the Australian Capital Territory, you might pay an hourly rate of $90 and $75 in South Australia. Hourly rates for Western Australia and New South Wales are $90 and $100 respectively. A comprehensive budget should cater to any cost increases and unavoidable additional costs.
There is no set formula for calculating the costs of excavation, however, an excavation cost calculator can help. Everything depends on the type of excavation you must perform, the equipment required and the experience of workers who will be performing this task. The above-mentioned factors can make a difference between a total cost of $4000 to excavating your garage ground for as little as $800-$1000. If you lack proper equipment or have little or no experience, then hiring a professional excavation contractor to do it would be your best option. An average figure that one should expect for trench excavation will be somewhere around $100 per cubic metre, while rock excavation will range from $150-200 per cubic metre. This estimate is very general for most excavation companies.
Once the excavation has been completed, you will need to level land. To do this, you can use fill dirt which is used for several purposes such as levelling trenches and low areas or building up slopes.
Fill dirt generally comes in large tip trucks. You can get them from nearby earthmoving companies, excavation equipment suppliers or local landscaping suppliers who also sell fill dirt for levelling purposes. It can also be carried on track-mounted mini dumpers at the project site.
To make sure that the fill dirt does not sink over time, you will need to compact it correctly. The best way to do this is to use a plate compactor which is basically a large metal plate with an upholstered roller attached to its bottom surface. This device can be rented at construction supply stores or tool rental shops. A walk-behind roller can also be used as long as it has the same upholstery on its roller face as the machine-mounted versions. Multiple passes over the surface with these machines should be enough to compress the fill dirt and make it firm. Remember though, that if your garage ground is on top of hard rock, then compacting fill dirt will not get you anywhere since it cannot get below the rocks. In cases like this, you need to bring in gravel or crushed stone which can fill any gaps between the rocks. This material can be found at landscaping suppliers and is usually sold by weight.
There are several methods to compact soil including but not limited to manual tamping or using gas-powered plate compactors or using an electric vibrating plate compactor which you can rent from tool rental stores. An alternative to this type of equipment would be to use a walk-behind roller. Make sure that the weight of the machine used will be enough to adequately level out the soil without leaving any empty spaces under it. The face of the machine should also be large enough so as not to leave any indentations in the soil. Remember to also check for rocky areas before using the machine.
Trenchers can go on either tracks or wheels while power hammers generally come only on tracks.
Both types require operators who have extensive experience with this kind of heavy machinery. Rock removal costs an average of $150 for every cubic yard. If the equipment is rented, daily rental costs will be more. For more information on staying safe around excavation work, take a look at the Safe work Australia guidelines.