Testing for radon in a multifamily building is different than in a single-family home because you need to understand how the gas moves between units. We placed test kits on the lowest livable floor of every apartment and in common areas like the basement to get a complete picture. The results showed that one side of the building had higher levels due to a crack in the foundation slab, so we targeted sealing there rather than treating the whole building. multifamily radon testing 4
