As the longer term readers of this blog know, we have a basement finished at living space with superior walls. The superior walls are a concrete custom constructed panel designed to lock together at corners. It has the benefits of producing a stronger more disaster resistant product and lower energy costs over time. Following construction and finishing, we had the radon levels measured there, which fell well 2 picacuries. Then, just after the 5.8 Virginia earthquake in 2011, we decided to have the radon levels rechecked, and found them to be higher. We then invested in a continuous radon monitoring device, and found that prior to additional earthquake aftershocks that the radon would spike, and decrease somewhat afterward.
Radon higher than 2-5 picacuries intermittently is not dangerous. However, experts think that anything beyond 5 should be remediated. Even a house closed up, and revisited which is a ten is probably not a problem. Higher than normal radon levels over years can increase the chances for lung cancer, especially in smokers. Fortunately, a huge amount about radon remediation has been learned since in 1980s when this became much more of an obsession for homeowners, especially those living in parts of rural NJ, on subterranean uranium beds which leak radon daughters to the surface, which are held in, in particularly energy efficient homes.
We have used the continuous radon monitoring device for the last couple of years, and as the aftershocks have waned, so has the radon. We did plan, however, to have a radon venting system added to the house at a later date. We did this because we have finished living space on the lower level including a full bathroom, and three additional bedrooms. That later date was this weekend. The very best book for learning about radon and remediation is
Protecting Your Home from Radon: A Step By Step Manual for Radon Reduction
by Douglas L. Kladder (Author)
In many homes, relatively very easy actions can be taken by the homeowner which will drop the radon levels significantly, and this is why the book is such a good investment.
Although our levels did not require us to remediate, we needed to look at how much time we do spent in our home, particularly time to time. The fact that people sleep in our lower level meant that any elevations whatsoever should be addressed if possible. Also, in an emergency, we could all be living on our below ground level. We had a more complex situation by virtue of the large size of the structure, and the slab being below the basement floor, rather than a crawl space. In addition, the very thick custom superior walls made retrofits more challenging. To consistently keep the radon levels below 2 picacuries under all seasons, window conditions, power outages, and pre-quake and after-quake conditions, we needed to have installed a different system than many.
Sometimes, a specialized radon venting fan can be installed, with a vent piping, outside the building, but we did not want this outside the home. For us it was necessary to have someone drill through a particular region of the basement concrete slab and to install a large PVC pipe which came up through the house through all the levels and then vent through the roof, where it would be capped. In the attic, there is a specialized fan which was installed with the intent of changing the pressure gradient sufficiently to vent the radon out through the top of the house, and away. This was a challenge only because the large pipe could not be visible in the house. It had to traverse through walls or regions that would not be seen, and this took planning. The fan also needed to be wired in to a place in one of the attics where it could be accessed and maintained as needed. Then, we had to have the money to do this, when it wasn't financial priority one.
You can buy replacement Fantech fans here
|This is another type of radon venting fan made by the same company.|
The above fan can be purchased here.
|This is what many radon remediation systems look like. We wanted ours hidden inside.||(Picture by: http://www.central-va-radon.com/|
|Here is a more hidden fan|
In a week, we will have new measurements of radon from each room with the new system working. Let's hope each room is below 2.0 picacuries, which is our target !
This is health information and risk assessment materials from an authoritative source concernign radon, and specific radon levels.
Radon Health Information and Risk Assessment Data
US Radon Map Zones
Radon can be an issue all over the world, as well as the US and Canada.
My prior posts on different aspects of radon:
UPDATE: October 26, 2013 I am happy to report that all finished and unfinished basement rooms fell below 2.0 picacuries when measured two weeks following final installation. The real test would come when Winter came and when windows would no longer be open, and the basement would be closed to retain heat.
In the last week an early cold came through, and we saw our first hard freeze. Temperatures were 34 degrees F overnight. The continuous radon monitor confirms that our radon levels are 1.8 in all measured areas. In addition, the fan at the top of the page, which lives in the attic, and we cannot hear, has not made a palpable difference to our electricity bill, despite the fact that it runs continuously.