BSI-127: Pests Can Really Bug You | Building Science ...
The pea gravel – crushed stone ground break should slope away from the building at approximately 5 percent (1/2 inch per foot). Figure 3 : Pea Gravel – Crushed Stone Perimeter Pest Resistant Ground Break – Slab Foundation - The thickness of the pea gravel – crushed stone layer should be a minimum of 4 inches.