Commercial grading is a very specialized phase of the construction process. Without proper ground preparation, construction results could vary widely from the architectural concept, groundwater may create structural problems, and improper drainage could have negative environmental impacts.
It is critical to create and execute the site grading plan professionally and to exact specifications for everything from a parking lot or small restaurant to high-rise office buildings.
What is Site Grading?
Any construction site requires some preparation before building begins, including land leveling and grading activity. Grading consists of sculpting an area of land for the needs of a specific project. The goal of grading is to:
- Provide the desired aesthetics of the property
- Ensure proper drainage
- Comply with zoning and other regulatory restrictions and requirements
- Establish allowable height and depth of cuts, fills, and swales
- Protect the environment with consideration for stormwater runoff, potential pollutants, and erosion
Benefits of Construction Grading
Grading and site preparation for construction projects is important not only for the structure being built but for neighboring homes or other buildings.
Improper grading can mean water runoff will move toward the building rather than being directed safely away. This can cause structural damage from hydrostatic pressure where water accumulates around or under the foundation.
Poor grading can also result in water or pollutants being directed toward other properties, creating liability for the builder or owner of the new facility. Property damage from erosion can also occur.
Many planning and zoning jurisdictions require approved grading plans before beginning construction to guard against problems caused by improper grading or lack of compliance with land grading standards.
Types of Grading in Construction
What does grading a lot mean? There are multiple types of grading in construction projects:
- Landscape grading – undergoing a landscaping project – municipal or commercial – may call for topsoil removal for installing irrigation systems, smoothing areas for planting, and modifying slopes or elevations to improve drainage or create a change in appearance. Landscape grading is often referred to as the process of reshaping a land area to modify water runoff patterns or otherwise alter property elevations. Getting the job done right is important to ensure proper drainage and to achieve the best results.
- Architectural Grading – changing the contours of a land area for a new home, housing development, or commercial property typically relates to changing the contours of the landscape to accommodate proper drainage, remove undesirable elevations, and prepare foundation areas.
- Regrading – regrading involves lowering or raising the levels of a land area. This can involve large areas or a small project.
- Finished Grade – for specific purposes such as gravel roads and earthworks projects, grading extends to include the surface and cover of the finished construction, not just the base. In landscaping projects, finish grading refers to finishing the final contour of the project, shaping the desired area to prepare for planting, seeding, or sodding. Finish grading includes putting the final touches on the grading project. This step provides a smooth surface with the removal of such items as large chunks of soil, rocks, and other undesirable debris.
- Rough Grading – setting the slope or leveling an area for such projects as landscaping, providing a base for turf development, or resolving drainage issues is termed rough grading. This may include adding, removing, or relocation of topsoil. This stage shapes the ground to the desired basic shape and elevations, creates the desired soil composition, and establishes the drainage flow.
- Final Grade – to complete the grading process and prepare for the final landscaping or seeding, there is often a need to finish the surface with a material that promotes growth. Final grading construction involves covering the area with a coating of screened topsoil or similar matter to complete the grading project.
Getting Approvals for Grading Projects
In many municipalities or regions, grading plans are required before work can begin, and inspections are required to achieve a passing grade after grading construction.
Grading projects are inspected, receiving a certificate of approval so that landscaping or construction can proceed. This approval indicates that the resulting elevations and proper drainage match the original grading plan.
Site grading plans contain several critical components for evaluation by planning officials:
- Lot size and structure coverage percentage – many jurisdictions have requirements for maximum allowable coverage of buildings or other structures. This value gives reviewers an immediate reference to determine if that requirement is being met.
- Earthwork estimates for cut and fill work – these statistics offer valuable information for how much material will be removed or brought in to accomplish the work.
- Property lines and any easements present, as well as utility lines.
Grading Techniques and Purposes
Grading is most often accomplished using modern heavy equipment such as excavators and bulldozers for a rough finish. For a smoother finished result, graders may be utilized to produce a finer finish.
Experienced engineers understand how land grading techniques will impact the final results. This includes:
- Meeting the needs and expectations of the client
- Provide the necessary drainage requirements
- Comply with all local, state, and federal requirements
- Consider all environmental concerns
What is the difference between grading and excavation?
These terms are sometimes used interchangeably, but there is a distinction. Excavation is usually done in the beginning stages of construction for such tasks as removing soil for swimming pools, creating walkway and sidewalk foundations, and digging trenches or channels for utilities.
Grading or leveling typically comes later in the construction process, smoothing surface areas and creating an aesthetic appearance for the property. Excavation is not always necessary for a commercial construction project, with site grading producing the desired preparation.
Why Site Grading is Important for Construction Projects
Site grading for construction projects has several objectives:
Prepare Soil for Structure Foundation
Whether the construction effort is a residential, light commercial, or heavy industrial project, preparing the foundation to support the building properly will prevent structural damage from settling caused by inadequate load-bearing properties.
Experienced grading engineers will have comprehensive knowledge of where compacting is necessary to support higher demands for the intended structure, and how runoff water must be controlled with grading.
Assure Proper Drainage
Controlling water flow from rain or other sources is a primary concern when creating a grading plan. Water must be directed such that buildings, other properties, and the environment are all considered in a responsible manner that meets all zoning and ethical requirements.
Create the Landscape Aesthetics Desired
Land leveling and grading will be essential to create the desired architectural image of the finished property. This takes into account elevations and leveling needed for walkways, parking areas, driveways, patios, gardens, and other elements of the site plan.
Site Grading Basics
Before grading can begin, civil engineers will create a comprehensive grading plan, describing in detail the proposed work to be done.
What Does a Grading Plan Show?
Grading plans are complex documents that include a wealth of information for engineers, construction planning, and authorities such as zoning or building commissioners.
Anyone taking a look at a grading plan for the first time can be totally baffled by the complexity and the various types of lines, numbers, and arrows. Site grading plans contain a wealth of information related to the site’s current condition and the proposed grading results. This allows examiners to evaluate the plan and either approve, make changes, or deny permits for the work.
How Do You Read Construction Grading Plans and Elevations?
Following professional standards simplifies the interpretation and reading of grading elevations.
Grading plans provide a 3-dimensional depiction of a site, indicated by contour lines that follow the site’s elevations, typically set in 2-foot changes in elevation. Therefore, a grading plan with contour lines farther apart will indicate a gentle slope, while more compacted contour lines reveal a steeper slope.
Contour lines presented in dashes indicate the site’s current contours, while solid or bold lines are used to indicate the proposed contours.
Other information presented on a grading plan includes “spot elevations” that indicate the relationship to mean sea level – critical in some areas. Here again, existing and proposed values are typically represented with “x,” indicating existing values, and “+” for the proposed position.
Grading plans also provide valuable information that about trees, property lines, proposed and existing drainage lines, or other mechanisms. Additional information critical to the grading process is included, such as current underground utilities that need to be considered in grading activity.
Illustrations of Site Grading Plan Examples
Site grading plans will vary somewhat in content, depending on the existing and planned topology, but these examples provide a high-level look at their appearance.
Images source: Tranquility Computers
A quick look at these examples will demonstrate why an untrained eye can be confused rather than informed by the information contained in such grading plans. Creating and interpreting commercial site grading plans is a skill developed from education and experience.
What Does a Grading Plan Cost?
Both excavation and grading involve the use of heavy equipment and specialized skills in its operation. Creating a comprehensive grading plan is typically done by experienced, certified civil engineers or licensed architects.
Most municipalities and many homeowner bylaws require detailed grading plans for approval before work commences, especially for significant projects or those with potential ecological impact.
Special considerations will be necessary for areas with unique environmental considerations such as seismic activity, nearby wetlands, water tables, or wildlife habitats.
Grading plan costs will vary depending on the scope and lot size addressed in the grading plan. There are additional factors that could also come into play – drainage requirements, neighboring properties, earth composition, underground utilities, and others.
How to Get Started with a Site Grading Plan
Providing an accurate grading plan that optimizes the efficient use of existing materials will save money during the actual grading construction process. Cost-saving methods include utilizing existing soil that is being extracted from one area to fill in others, rather than simply removing materials. This results in less material movement, saving time and expense.
Stovall Construction has 50 years of experience in commercial construction and general contracting services. We can help you prepare an efficient site grading plan that saves time and money on your projects.
Contact Stovall Construction for more information about your grading projects and commercial construction needs.