There are several processes and aspects to subgrade preparation for concrete slab placement and installation.
What Is Subgrade Material
First of all what is subgrade material? Subgrade material is the native and or man made placed material under construction projects. The construction projects can be roads, highways, pipelines and or building and structures.
Know What To Look For
Knowing what to look for in subgrade preparation is key to a successful and long lasting construction projects. Subgrade work is the proper placement and compaction of earthwork materials. These materials serve as a base for the building of a structure or road construction project.
The importance of testing with desired results will lead to the longevity and durability of your project.
Types Of Subgrade
- Bedrock; this is the solid rock buried underneath soil and unconsolidated materials.
- Compacted Subgrade; this is the process of compacting the existing soils.
- Selected Material; the selected material is placed and compacted and tested for desired results.
- Subbase Course Material; placement of this material, hardens the immediate area and improves heavy traffic use.
- Base Course Material; provides for support of the top surface layers of materials.
- Leveling Course; this thin layer of material is applied over existing subgrade material for leveling.
- Binder Course; coarse aggregate bound with bitumen between foundation and wearing course in asphalt pavement.
Questions:
What is subbase and subgrade?
These are the materials that exist below surface materials.
What is the subgrade layer?
How do you increase subgrade?
What is road subgrade?
What is subgrade preparation?
What are the desirable properties of subgrade soil?
Subgrade Placement
With your unique project, you may be tasked to apply different materials. These materials will vary from type and depth. The placement of the materials will require compaction. This compaction is often inspected with commercial projects. Make sure to have all proper testing performed and documented.
Subgrade Compaction
The placement of the materials will require compaction. Subgrade material compaction is often inspected with commercial projects. Make sure to have all proper testing performed and documented.
Residential Driveway Subgrade Preparation for Concrete Slab
- Grade to uniform depth.
- Compact existing material.
- Install 4 inches of 21a (Crushed Run)
- Dampen the newly placed 21a.
- Compact 21a
- Place stabilization sheet (geotextile fabric)
- Install 6′ x 6″ #10 wire mesh.
- Install 4 inch thick 4000 PSI strength concrete.
Finding Subgrade Soil
Finding an onsite soil for subgrade use can be a hard task. Soil quality is highly dependent on the location of the project. Because of this, dirt is often brought in from an outside source, such as having truckloads of fill dirt delivered.
Ensure Optimal Subgrade Preparation with Quality Fill Dirt and Grading Assistance
For more on residential construction, please visit our residential services page.
If you need reliable dirt delivery and professional residential dirt grading assistance, get in touch with Dirt Connections today by giving us a call or sending us a message online.

