Body Tag (as high as possible):

Creating a pea gravel sub-base for your concrete slab is a straightforward process that involves several critical steps to ensure the stability and longevity of your concrete. Here’s a detailed guide to help you through the process:

Materials Needed:

  • Pea gravel (purchase from Saunders and have it delivered for FREE)
  • Compactor (plate compactor or hand tamper)
  • Geotextile fabric (optional)
  • Measuring tape
  • Shovel and rake
  • Straight edge
  • Pressure-treated wood boards (for framing, if necessary)

Step-by-Step Instructions:

  1. Excavate the Area:
    • Mark the area where you plan to pour the concrete slab.
    • Excavate the soil to a depth that allows for a 4-6 inch layer of pea gravel plus the thickness of the concrete slab. This typically means excavating about 7-10 inches deep.
    • Ensure the area is clear of vegetation, roots, and debris​.
  2. Prepare the Soil:
    • Compact the soil at the bottom of the excavation using a hand tamper or plate compactor. This step is crucial to remove air pockets and create a stable base.
    • Optionally, lay down geotextile fabric over the compacted soil to prevent soil erosion and mixing with the gravel.
  3. Frame the Area (if necessary):
    • Use pressure-treated wood boards to frame the area, ensuring the edges are straight and level. This helps keep the gravel contained and provides a guide for the concrete pour​.
  4. Add and Level the Pea Gravel:
    • Spread a 4-6 inch layer of pea gravel evenly across the excavation using a shovel and rake. Ensure the gravel layer is slightly thicker in the middle to help with drainage.
    • Use a straight edge to level the surface of the pea gravel​.
  5. Compact the Gravel:
    • Compact the pea gravel using a plate compactor or hand tamper. If the gravel layer is more than 3 inches thick, compact it in 3-inch increments to ensure thorough compaction.
    • Check the level of the gravel frequently and adjust as necessary to maintain a uniform surface​​.
  6. Final Preparations:
    • If using rigid foam insulation, place it on top of the compacted pea gravel. Ensure the foam boards fit snugly and do not interfere with the gravel layer.
    • Consider installing a vapor barrier directly above the gravel and foam to prevent moisture from wicking up into the concrete slab​.
  7. Ready for Concrete:
    • Once the pea gravel sub-base is properly compacted and level, you can proceed with pouring the concrete. Ensure the concrete is poured evenly to avoid creating weak spots​ (Plasticine House)​​ (Hunker)​.

Following these steps will help you create a strong and stable pea gravel sub-base, ensuring the durability and longevity of your concrete slab. Proper preparation and attention to detail at each stage are key to a successful project.