In 2009, the Minnesota State Building Code turned to the International Residential Code and adopted Appendix F. After this, the new homes built in the state have to be built with no less than a passive radon mitigation system. The reason is to keep the high levels of radon down in Minnesota. In fact, it has been determined that 40 percent of homes in the state have raised levels of radon gas within them. This has to do with both geology in the state and winter-tight homes.
There are four sections to Minnesota’s radon requirements that outline how these systems are to operate, what is acceptable, and other requirements.
In these guidelines, it is stated that a passive radon mitigation system is to have a 4 inch layer of sand or rock underneath the basement slab and a soil gas retarder that must sit on top of that. The soil gas retarder is designed to prevent the soil gasses from coming into the home through concrete cracks. This is one reason why all of the openings in the basement floor need to be sealed off. Cracks around basement walls and slabs, as well as basement showers, need to be taken care of. Sump basket lids also need to be sealed tight.
To make sure that cracks are sealed, your Minneapolis contracting company can make sure the basement is tight so that the radon that is naturally in the ground doesn’t seep into the basement, thus keeping radon levels low.
The idea is for radon gasses to be vented to the exterior of the home. A PVC pipe runs underneath the basement slab where it is connected to the drain tile system. From there, the pipe runs up through the home and stops around one foot above the roof’s surface and looks like a plumbing vent. However, the pipe is labeled so it is not mistaken for plumbing.
These systems are highly effective, being installed in new homes for at least the past four years. So far, these systems are performing well. Although around 40 percent of Minnesota homes have high levels of radon, the Minnesota Department of Health conducted a study that showed only 21 percent of the new homes that have passive radon reduction systems installed have high radon levels. If a high level of radon is found in a new home, then the fix is usually rather cheap and easy. The solution rests on the installation of a radon fan installed at the radon vent in the attic. A monitor in the basement can show whether or not the system is working. The fan is to extract the soil gas from under the house and expel them outside of the home, which is effective in reducing radon gas levels.
The Minneapolis roofing company that you work with will have already installed the vent in the attic, so all that needs to be installed is the fan.
After that, the system just needs to be checked periodically.