What is required to seal foundation openings in radon mitigation?

Sealing cracks and joints is essential in radon mitigation because these openings are the primary pathways through which radon gas infiltrates a building. During the construction of a home, cracks and joints can form in the foundation, walls, and floors due to settling, temperature changes, or poor construction practices. If these areas are left unsealed, radon gas from the underlying soil can easily migrate into the building, posing a health risk to the occupants.

Properly sealing these cracks and joints using appropriate materials like caulk, foam sealants, or other sealers helps to create a barrier that restricts radon entry. This process is a critical step in radon mitigation systems because it addresses the entry points of radon directly, thereby reducing the concentration of radon indoors.

The other options, while related to construction and building maintenance, do not directly address the specific requirement for sealing openings to prevent radon infiltration. Replacing foundation walls is typically an extensive and costly process, improving drainage systems focuses on managing water, and implementing vapor barriers is more about moisture control than addressing radon entry points directly.