Grade and Compact Sub-base
At 0:04 in
So exciting to watch this go up
What happens here
After the initial spreading, meticulously grade the sub-base material to its final desired elevation, ensuring the surface is perfectly level or has the appropriate slope for drainage as planned. This state is referred to as being "up to grade." Once graded, use a vibratory plate compactor (like the blue unit visible in the video) to thoroughly compact the material. Make multiple passes in overlapping patterns across the entire area to achieve maximum density. Proper compaction removes air voids, increases the material's load-bearing capacity, and prevents future settling of the concrete slab. If the material is too dry, lightly add water using a hose with a spray nozzle, as moisture can aid in achieving optimal compaction.
Goal: Create a uniformly dense and level sub-base.
Tools and materials
- Hearing Protection — Protecting ears from the loud noise generated by the plate compactor
- Level — Checking for the final grade and ensuring the sub-base is level or correctly sloped
- Rake — Fine-tuning the level of the sub-base before and during compaction
- Safety Glasses — Protecting eyes from dust, flying debris, and aggregate during compaction
- String Line and Stakes — Setting precise grade lines to guide accurate leveling of the sub-base
- Vibratory Plate Compactor — Compacting the gravel sub-base to achieve maximum density and stability
- Water Hose with Spray Nozzle — Lightly wetting the sub-base material to aid in achieving optimal compaction