Transport Mechanisms – Forces That Move Radon Through Soil & Rock

Radon movement from its source into a home is powered in one of four ways (Figure 3-6):

1. Well Water (<1%).
2. Diffusion from soil to indoor air (1-4%).
3. Emanation from Building Materials (2-5%).
4. Soil Gas to Indoor Air via Pressure Driven Airflow (85-90%).