Short circuit sealing is extremely important to the radon mitigation process.  However, it is important to note that sealing these cracks and fissures in the slab and foundation is not a technique to be used alone for Colorado Radon Pros mitigation or radon reduction.  The purpose of sealing cracks, or sealing other easy access points for radon to enter the home, is to help create a negative pressure differential under the slab.  This is to say that, sealing alone will not stop radon from penetrating the structure.  In fact, radon is a very small molecule, even smaller than water, and because of this, any material water can penetrate, radon can also penetrate. Moreover, the true purpose of sealing is to help enhance the vacuum seal and pressure created beneath the slab for better mitigation results and also to avoid potential back drafting of applicable appliances.  Because radon always finds the path of least resistance, properly sealing and creating this vacuum pressure will draw the radon into the the piping and the fan will help exhaust it at the proper level above the roof-line.