How Radon Gets into Homes? Radon gas is found in homes all over the U.S.
Radon is an invisible and odorless radioactive gas. Higher levels of radon have been found in homes all across the country. Any home in any state may have a radon problem: new and old homes, well sealed and drafty homes, and homes with or without basements. Radon gas gets into all types of buildings, including office buildings and schools.
The average person receives each year more radiation from radon than from all other natural or man-made sources combined. Over the years, the accumulated radiation exposure may exceed the exposure of uranium miners.
As radon gas moves through underground fissures, it usually decays into solid particles after several feet. But it travels much farther in dry, permeable soils, like gravel or course sand.
Radon is soluble in water and underground streams can carry it long distances. This unpredictable underground movement of radon gas explains why homes in low-radium areas also have high radon levels and why radon levels can vary several-fold between adjacent houses.
Radon gas naturally moves into the permeable disturbed soil and gravel bed surrounding foundations and then, into the buildings through openings and pores in concrete. Radon from soil is by far the main source of indoor radon.
The air pressure inside homes is slightly lower than in the ground air pressure (typically 0.7-1.4 psi vacuum), which draws in radon gas from several feet away. Combustion appliances, like furnaces, hot water heaters and fireplaces, as well as exhaust fans and vents lowers the indoor pressure indoor.
The warm air inside buildings moves upwards like inside a chimney and this “chimney effect” turns the air pressure on lower floors into more like a vacuum. Strong winds create a vacuum on the downwind side by the Bernoulli effect.
When the ground is frozen or soaked by rain, the “bottled up” radon gas in the ground moves to the warm and permeable gravel and disturbed ground around the house.
RadonSeal reacts with concrete and seals the capillaries (pores) against radon atoms, as well as the larger water molecules. Instead of removing radon from underneath the slab by a fan, it simply seals the concrete and leaves the gas in the ground.
Sealing the pores stops radon diffusion and advection through the slab and the walls. At the same time, it blocks water migration and reduces emanation from the concrete.
RadonSeal does not depend on the permeability of soil and the reliability of mechanical equipment or the power grid. It does not spew a plume of heavy, radioactive gas above the house.
And if a sub-slab depressurization system is already installed, RadonSeal will lower its energy losses (treated air drawn through the slab) and will reduce the radon level further.
RadonSeal never has to be applied again because it cures as a mineral and seals concrete permanently.