Inspectors can use a few different methods to reduce and prevent radon from entering a home. The EPA has suggested that preventative methods are best and should be considered for all homeowners.
One of the most basic approaches to radon reduction is sealing cracks and other openings in the floors and walls. Sealing cracks does two things, first it limits the flow of radon into your home and also it reduces the loss of conditioned air.
That being said, the EPA does not recommend the use of sealing alone to reduce radon levels. This is because sealing has not been shown to lower radon levels significantly or consistently all on it’s own. It can be very difficult to identify and permanently seal the places where radon is entering. Over time, the normal settling of your house opens new entry routes and reopens old ones. Consider a radon test for your home if it’s been decades since it’s construction.