Illinois Home Inspector Exam 2025 – 400 Free Practice Questions to Pass the Exam

Radon typically enters a home primarily through cracks in the foundation. This occurs because radon is a naturally occurring gas that seeps up from the soil into the living spaces of homes, particularly through any openings or fissures present in the foundation, such as cracks in the basement slab, gaps around pipes, or other structural weaknesses.

The nature of radon, being a gas that is denser than air, allows it to accumulate in lower areas of the home, such as basements or crawl spaces. Homes that are built on soil rich in uranium are especially susceptible as uranium breaks down into radium and eventually radon gas. Although other elements can contribute to radon entry, such as construction materials that may contain radon, the primary path remains those structural cracks and openings in the foundation.

This understanding highlights the importance of proper foundation sealing, ventilation, and radon testing, particularly for homes in areas known for higher radon levels.