How does Radon
get in you house.

As stated in previously, radon is a naturally occurring gas that is present in the soil below your home. The radon migrates through the soil under your floor and eventually finds its way into your home. Radon can enter your home through many paths such as cracks in the foundation, cracks in a concrete floor, utility penetrations, sump openings, floor drains and the list continues. It only takes very few minute openings for the radon to enter your home. In theory, you could keep the radon out by building an air tight foundation and basement floor however, due to normal shifting of your home and cracks that develop in the concrete, it is an impossible task with today's technology.

Attributing to the migration of the gases are the pressures of the dwelling. Buildings create negative pressure differentials that can draw in the radon gases. A good example of this is the stack effect. When we heat our homes, the warm air rises from the basement up to the upper levels. Eventually some of this warm air escapes through places like windows, doors, attic access panels and etc. When any air escapes, a slight negative pressure develops because your home is trying to draw in new air to replace the old air. Since the upper levels of you home has air going out, the air will enter your home from much lower points, such as the basement. This causes your home to act like a vacuum cleaner, in a sense, sucking on the soil below your basement.

Ventilation of a building can effect the radon concentration too however, in Minnesota, contractors follow extensive energy codes set forth by the state. These codes produces houses that are extremely tight, meaning there is not a lot of transfer of outdoor air with indoor air. This gives the radon one less path to leave your home, in fact, it will cause the radon to accumulate in your home.