Site work was minimal this week; our excavators made a return visit to finish filling the house foundation with washed gravel—four inches is necessary for the radon abatement system. Before the floor insulation is installed, plumbers will dig a network of 4-inch perforated pipes into the gravel; this allows radon gas to escape through the pipes, out an exhaust, and into the atmosphere, rather than into the house.
Radon gas is a significant issue in this part of Minnesota. For the uninitiated, radon is a colorless, odorless and tasteless radioactive gas that occurs naturally in most rocks and subsoil. As minerals break down in the soil, the gas is released and in places like southeast Minnesota, where the underlying geology is composed of broken layers of limestone, the gas can easily rise through the subsoil, seeping unknowingly into basements and houses. It’s estimated that more than a third of existing Minnesota residences—even more in this area—harbor potentially dangerous levels of radon. Prolonged exposure to high levels of radon is the second leading cause of lung cancer in the United States.
More information about radon can be found in Radon: Keeping Your Home Safe published by the Minnesota Department of Health.
Next week, materials and contractors are due to arrive to begin framing the garage – hooray!