Radon systems for all
Radon systems for all
January 30, 2017 | by David Daniels, Radon Specialists of Wisconsin
Then and now
In contrast to when I first started my business, today, most people have heard of radon gas. “Radon” used to be a dirty word. No one wanted to hear about it, much less talk about it. Back in the day I remember standing in front of a builders group I had just joined. I didn’t get that warm fuzzy feeling as a new member. I was the enemy. Fast forward to 2017. Radon Specialists of Wisconsin, Inc. now installs systems at many new construction sites in homes all over the state. Builders call us for advice and understand the benefits of radon systems.
Risks, prevention and system benefits
An elevated radon level in a home is no one’s fault, it is a naturally occurring gas. Failure to take measures to prevent it is another case. Radon is the leading cause of lung cancer in non-smokers; cancer that can be prevented. It is my belief that, at a minimum, a passive radon system should be installed in every home. As I see it, there is no down side. If a home tests high after construction a fan can easily be added to a passive system to make it active in order to reduce levels. In addition, radon system piping will be located in the wall improving aesthetics and pipe insulation.
A side benefit to having an active radon system is the moisture reduction effect. Because an active radon system is pulling air from under the basement slab 24/7 the soil underneath the home begins to dry out. Some homes have more of a drying effect than others but it helps on all. Many systems have been installed for the moisture reduction benefit alone, even when radon levels are low. It’s great to see a basement at 45 percent humidity in the summer.
Finally, if you choose to have radon systems installed in the homes you build, you can use that information in your marketing.
There is a misconception that radon doesn’t have to be addressed if the basement isn’t finished off. Radon levels can still be high on a first floor depending on how air moves through a house and how high the levels in the basement are. I’ve heard people make the statement: “You’d have to spend 75 years at high levels for radon to do any damage.” The truth is, if you spend just eight hours a day at a level of four picocuries, you are exposing yourself to the equivalent of 200 chest x-rays of radiation to your lungs, per year. Radon is radiation. A safe level is zero.
What a system needs to do
Radon systems need to create air flow under the slab from footing to footing. This is considered the suction field. To prevent air loss, large leaky cracks or gaps need to be sealed—if not addressed the system may not be able to lower radon levels, plus, heating and cooling costs could go up. A sump pit with interior drain tile also needs to be air tight, with no venting. All in all—the suction field needs to be closed to work properly. Keep in mind, it is not true that radon systems have to be routed off the sump pit. The pit is the last place a system should be placed. If an owner has to get into the pit, they’d have to take the radon pipe apart.
Radon systems have a few standards that must be met. The fan in an active system must be located in unlivable space. Typically the fan is located in the attic of a home or garage. The vent must be a minimum of 10 feet above grade and 2 feet above any openings within 10 feet of it. A function indicator must be located on the piping. We usually use a simple manometer. Finally, EPA recommend radon levels to be at or below 3.9 picocuries.
Building Wisconsin homes
Homes in Wisconsin are constructed differently in many areas because of the various soil types present. In the Appleton area for example, homes have gravel as a sub slab material with drain tiles. In Waupaca, most home foundations are poured right on top of sand with no drain tiles. This can make radon system installation a little tricky. When there is gravel it is easy to pull air from under the basement slab, which is what radon systems need to do if there are elevated levels. When there is only sand present the air flows much slower or not enough with just one suction point. Many times a larger vacuum fan has to be used raising the cost to mitigate and operate a radon system.
If a home doesn’t have gravel as a sub slab material at least a 3- or 4-inch perforated drain tile should be laid down on the interior footing of the home with a sock on it to prevent sand or sediment from entering the tile. This approach will guarantee that, if an active radon system is needed, it will be a highly efficient one and will cost less in the long run.
The best time to install a radon system is during the rough in stage. Radon Specialists of Wisconsin, Inc. usually arrives after the framing is done and the sheeting is on the trusses. If the slab is poured, we core through it for the suction point as long as the slab is a week or more old to prevent crumbling. If a fan is added right away for an active system, an electrician should be contacted as soon as possible to get it hot. With the system running the concrete will cure faster. Also, a fan that is installed for a long time without running can begin to rust.
More and more people are becoming aware of the dangers of radon and most already know about moisture issues. If you consider the cost of installing a radon system during construction you find there really isn’t a downside. And, in the long run you could save someone's life.