Whether you plan to erect a commercial or residential site, excavation work is essential to guarantee a reliable foundation.
Every construction site has unique characteristics, but the site needs preparation for the foundation. Therefore, excavation is among the most critical construction processes, as it determines the suitability of a foundation in a project.
This article provides information on the various pre-construction excavation works, their importance, and how much they cost.
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What is Land Excavation?
Land excavation is more than digging holes in the ground. It is the process of removing soil from a workplace to form a trench, cavity, or tunnel. Land excavation involves heavy machinery like bulldozers, excavators, backhoes, and forward loaders.
Though excavation is typically used in construction to grade and lay foundations, it can be multi-purposed as it can involve tunneling, creating wall shafts, and earthworks.
Excavation is essential for all projects as it creates a strong foundation for a construction project. Only experienced engineers and contractors can determine the excavation work necessary for a project.
Why Excavate land?
Excavation is vital in determining the capability of a structure to withstand stress. It helps link the distinct features in a project. It helps prepare the land before actual construction works commence. Clearing the site of unwanted boulders and rocks and moving the earth makes it possible for further works to proceed on the structure.
Excavation also helps in trenching for building septic tanks and channels for drainage pipes, which is vital for any construction project.
How is Excavation Priced?
Excavation is priced as per the volume in cubic yards of dirt removed. Small projects cost less than big ones, and the cost is also higher for projects with difficult-to-reach areas than for easily accessible projects. A small job can cost $100 an hour, while big jobs cost over $500.
The equipment used in an excavation job affects pricing, as excavation machinery is expensive to maintain.
The time of the year also influences excavation costs. There are some periods when contractors are offseason, and they are likely to offer lower prices, especially during early Spring or late Fall. However, it would be best to confirm whether the outdoor temperatures affect your construction work before hiring.
The soil type in your area affects excavation costs. Soft ground is easier to excavate than hard and stony ground, which will cost more. The project's location also affects total costs. The farther away the project is from the excavation company, the higher the excavation costs.
As you can see, several factors affect the pricing of excavation works, and it is best to work with a licensed cost estimator to get a fair quote.
Average Excavator Hourly Rate
A typical excavation job costs anywhere between $40 to $150 an hour. However, it might not be easy to find contractors willing to work at an hourly rate, as most prefer quoting per cubic yard or an entire project.
A residential project costs anywhere between $50 to $200 per cubic yard, and the total cost of excavation in a residential project can run between $1445 and $5430.
The hourly rate majorly depends on the project's layout, geographical location, and challenges present in the job.
Land Excavation Costs
There are different cost factors included in land excavation costs. Below are the main expenses incurred during land excavation.
One of the high land excavation costs is grading. Grading helps adjust the slope and soil elevation in a construction site before beginning construction works. It is necessary before actual excavation, as it helps remove earthen materials to create an even surface and help create a solid foundation.
The average grading cost is $500 to $1000 for small yards but significantly varies with site conditions. It costs an average of $1000 to $5000 to grade a home lot or an average backyard.
Like excavation, grading uses heavy equipment, and certified civil engineers prepare a comprehensive grading plan. Most municipalities have by-laws that require homeowners to have licenses and a detailed grading plan before starting the work.
Areas with unique environmental considerations like seismic activities and wetlands also significantly affect grading and overall land excavation costs. Additional factors like neighboring properties, drainage requirements and underground utilities also affect grading costs.
Though engineers understand design standards, it is best to refer to municipal land development laws to determine how they interact with existing works.
Site cut and fill
A site's cut and fill targets minimizing waste reduction as much as possible. A project with more cut than fill forces the project managers to find somewhere to dump the excess wastes and a project with more fill than cut forces the project managers to bring dirt from another location.
Additional cut and fill increases material, labor, and equipment costs. This additionally influences overall excavation costs. It is necessary to plan how to keep the cut and fill at approximately equal volumes to minimize the need to cut or fill the excess mass.
Though it effectively conserves landmass, cut and fill is expensive, and the costs increase as more land moves. To help maximize the efficiency of the process, site planners utilize a cut and fill map.
Though cut and fill utilize the existing terrain, detailed planning is necessary to make the process smooth. Project planners need detailed survey information and software to help them process data in a meaningful manner.
Cut and fill maps illustrate areas where cut and fill is necessary. These maps have exact measurements of elevation and topography. These maps are generated from precise measurements of the existing elevation and topography.
After determining the cut and fill necessary in your project, you need to plan out your labor and construction costs. Various software is available for generating cut and fill maps and automatically optimizing excavation costs.
Land leveling is flattening and smoothening a site's surface before construction starts. Leveling is also used to correct drainage issues and prevent soil erosion. It requires special equipment and is costlier if the land is enormous.
Land leveling costs vary with the type of project. Concrete patios and driveways cost anywhere between $1000 and $2500. Leveling for foundations for new constructions can cost anywhere between $1500 to $6000.
If you are leveling a site with many rocks and trees, the labor costs go up. This is because the contractor has to bring in more equipment and work longer. Additional fees may apply for topsoil landscaping and grading.
Re-sloping to improve drainage and erosion control also makes the land leveling work take more time, increasing the final costs. Some projects, especially huge ones, need special permits for land leveling, which can drive up overall costs. Consult your contractor for more information.
Several processes are involved in excavation. These include trenching, digging, dredging, and site development. Steep terrain and rugged ground conditions limit the accessibility of the weight and equipment that can be used on site.
Terrain with hard rocks or in cold winter areas is also hard on machinery, slowing down any construction activity. They also increase wear on the machinery, thus driving up construction costs.
In areas with very loose soils, it is difficult to protect the strength of the slopes after excavation. Protecting the slopes needs specialized techniques and equipment and costs more.
Machinery and Equipment
So much is at stake in a construction project, and having the right tools determines your project's success rate. There are different kinds of excavation jobs, such as lifting and moving, compacting and grading, or loosening of rock.
All these excavation jobs require specialized equipment. Before deciding on excavation equipment, you need to consider the nature of your construction site. The terrain, obstacles, hazards present, and need for dredging affect the type of equipment you need.
The comfort and skill of machine operators also determine the quality of work, and you, therefore, need skilled operators to get better results in your project.
Backhoe loaders are used for shoveling and moving dirt in small and medium-sized jobs. For big jobs, you might need a bulldozer to push piles of dirt. The excavator is also used for big jobs, and it has a big arm attached and is used for demolition, digging trenches, and lifting heavy objects.
Other excavation equipment includes trenchers, skid-steer loaders, spider excavators, and zero swing excavators. Your excavation equipment should always have the essential features and attachments to get the job done.
Other Factors to Consider
Other factors affecting costs that you need to consider before excavation include training and education of workers, emergency and rescue procedures, planning for adverse weather conditions, and potential hazards affecting soil stability.
Identify all power and overhead lines and all legislative requirements affecting your jurisdiction and the protective measures to be taken as they impact overall costs. Temporary protective structures such as trench boxes also drive up overall costs. Areas with monolithic ground that may require some blasting need special considerations during excavation.
As you can see, there are numerous factors affecting excavation costs. Construction excavation needs skill, experience, and expertise, affecting the entire project's foundation.
It is best to work with engineers and licensed contractors to help you get the best out of your project. A contractor that values safety and is known for quality work enables you to achieve the best in your project.