Excavation is a term used by construction companies that suggest the removal of the Earth. Excavation is used to create a cavity in the ground. Different types of excavation tools are required based on the size and space. Building and construction companies use a heavy plant for excavation. Hydrovac excavation is the use of high-pressure water to remove the soil. It is safer and more convenient than mechanical excavation tools.

Twelve types of excavation:

Excavation is an essential step in construction. Building and construction companies utilize various types of excavation to prepare a strong base for construction. The classification of excavation is based on:

  1. Material
  2. Purpose

Excavation by material:

The material removed or prepared by excavation suggest the classification of excavation by the material.

Topsoil excavation:

The exposed or topmost surface of the Earth is removed by using topsoil excavation. This excavation method is utilized to remove vegetation, soil and other decaying surfaces that can cause an issue in erecting buildings. These surfaces are not suitable to bear the structural loads.

Rock excavation:

Rocky surfaces cause hurdles in the construction process. Rock excavation can effectively remove the rocky surfaces, but this type of excavation is quite challenging. Special equipment and skills are required to remove rocky and rugged surfaces. High-pressure hydrovac excavation can effectively remove these surfaces. Blast and drilling are also utilized for this purpose.

Earth excavation:

The layer of soil that is present immediately beneath the topsoil is removed by Earth excavation. The material removed from the Earth excavation is called spoil. It is often stockpiled to be used for building foundations and embankments.

Muck excavation:

This excavation method removes the excessively wet material that is highly unsuitable for stockpiling the spoil. Muck, also referred to as a material that is formed by the combination of soil and water. The muck is then spread out for drying or moved to a different place.

Unclassified excavation:

When the excavation process involves removing multiple materials (as described above), the word “unclassified excavation” is used. Unclassified excavation is utilized when it is hard to distinguish between different soils removed during the building construction process.

Excavation by a purpose:

The purpose of the excavation process is also used to classify its different types.

Cut and fill excavation:

In this excavation process, the material is cut and stripped into smaller pieces. The topsoil, muck, or Earth is utilized to create embankment, elevated sections (critical in erecting the buildings), and other processes. The cut and fill excavation is used to create a level surface over which a building can be constructed. These elevated sections of the construction site are ‘cut’ then transferred to the pieces to fill the lower divisions.

Trench excavation:

Trench excavation is utilized where the length of the construction site is more than the depth. Shallow trenches are less than 6m deep, while the deep trenches are more than 6m deep. Trench excavation is especially useful in creating strip foundations and in buried services. The plant and technique of trench excavation depend upon the purpose of the trench, condition of the soil, location of the soil, and the number of obstructions.

Techniques of trench excavation are:

  • Full depth, full length
  • Full depth, successive stages
  • Stage depth, subsequent stages

Basement excavation:

The basement is referred to as a part of the building below the ground level, either partially or wholly. Basement excavation is used to create and build basements of the buildings.

Road excavation:

Road excavation is used to create stripping of the topsoil and cut-and-fill the construction site. Road construction companies often use it.

Bridge excavation:

Footing and abutment of bridges are done utilizing the bridge excavation. It is often a type of uncategorized excavation that is used to remove the rocks and muck. That is why it is divided into wet, dry, or rock excavation. Underwater excavation is a complicated process.


It is the process of removing sediments, slug, and debris that is present below water level. Dredging is utilized to clear the bottoms of lakes, rivers, and harbours.

Under-water sediments can cause hurdles in construction.

Over excavation:

Sometimes, unsuitable materials are required to be removed from the required depth. It involves the excavation beyond the necessary depth. That is why it is called over-excavation.

What is hydrovac excavation?

Hydrovac excavation utilizes high-pressure water rather than mechanical tools for excavation purposes. Hydrovac excavation results in “slurry,” which is the combination of mud and water. It consists of 60% and 40% solids. This slurry then is vacuumed to expose the deeper layers of the construction site. Daylighting is a process in which hydrovac excavation reveals the underground utilities. Two types of vacuum systems used in hydrovac excavation are:

  1. Fan system (for shallow excavations)
  2. Positive displacement blower (for heavy-duty excavations)

Benefits of hydrovac excavation:

Hydrovac excavation is the most popular alternative to mechanical excavation. The benefits of hydrovac excavation are:

  1. It causes minimal damage to the structures being excavated. It is instrumental in daylighting, which is used to expose underground utilities. The high-pressure water creates slurry, which is safely extracted with the help of a vacuum. Mechanical excavation uses backhoes and sharp metals to remove the soil.
  2. Hydrovac excavation is more accurate than mechanical excavation. The stream of high-pressure water is easily directable to create cuts in soil. The construction site is easily excavated with high-pressure water without causing damages to the surrounding environment. Moreover, the wands are easily transportable in more tricky localities.
  3. In cold months, hot water excavation is utilized to remove the frozen soil effectively. It is challenging to excavate the frozen soil with mechanical excavators.
  4. Mechanical excavation causes damages to the underground and surrounding structures that cause significant delays in completing work. On the other hand, hydrovac excavation is more timely, accurate, and safe. It is a delicate process that can efficiently excavate gravelly soils.

Building construction requires a lot of soil preparation. Excavating companies in Calgary provide services to prepare lands for erecting the buildings. The classification of excavation depends upon the material and purpose of excavation. Hydrovac excavation is the most modern type of excavation that is very safe, timely, and accurate. That is why construction companies in Calgary prefer hydrovac excavation over mechanical excava