Getting the ground right
Excavation removes soil, rock or old pavement to reach the depth the design calls for. Grading then shapes and levels the surface to set slope and drainage.
Oahu soils vary a lot, from red clay on the central plateau to sand and coral fill near the coast. Soft or unsuitable material is dug out and replaced with compacted base course so the pavement does not settle later.
Why Oahu Asphalt
- Drainage planned up front
- Slopes are set so water runs off instead of pooling or heading for your garage.
- Experienced operators
- Site prep by people who also pave, so the grade is right for what goes on top.
- Plans matched to the soil
- Excavation depth and base are adjusted to what is actually in the ground.
- Clearing through final grade
- One crew from demolition to a surface ready for asphalt or concrete.
What the work includes
- Site preparation
- Mobilize equipment, set up access and remove existing asphalt from work areas.
- Excavation
- Dig to required depths and replace soft or unsuitable soil with compacted base course.
- Grading
- Establish water flow and compact the subgrade to the specified density.
- Backfill and compaction
- Check compaction and moisture, coordinating engineering tests when required.
- Hauling
- Import select fill or export surplus, keeping haul routes clean and dust under control.
- Final grading
- Hit target elevations and slopes and leave the surface ready for paving, concrete or landscaping.
How it goes
Site assessment
We evaluate soil, elevations and drainage needs.
Excavation
Unstable or excess material comes out.
Rough grading
The ground is shaped for the base layers.
Fine grading
Slope and elevation are refined.
Compaction and inspection
The area is compacted and checked.
Recent excavation & grading projects
Excavation & Grading questions
Why does grading matter before paving?
Grading controls where water goes. Poor grading leads to standing water, cracking, rutting and early failure.
How deep do you excavate for a driveway or lot?
It depends on the design and the soil. Typically 8 to 12 inches is removed and replaced with compacted base.
What goes under the asphalt?
A compacted aggregate base course, usually three-quarter-inch minus base rock, which spreads loads and stabilizes the foundation.
How is compaction checked?
The subgrade and base are compacted with rollers and plate compactors, usually to 90 to 95 percent density per ASTM D1557.
How long does excavation and grading take?
A residential driveway is typically about a day. Small commercial lots take a few days and larger jobs a week or more, weather permitting.
What are signs of poor base prep?
Standing water, uneven surfaces, soft spots and cracks that show up early.
How soon should paving follow grading?
Right after final grading and compaction. Leaving the subgrade open to rain can mean regrading it.
Where we work
We provide excavation & grading across Oahu, including Honolulu, Kapolei, Ewa Beach, Pearl City, Aiea, Kaneohe, Kailua, Mililani, Wahiawa, North Shore and everywhere in between.