I used to test for Radon and have seen many systems installed and in place as an inspector, and had a few installed for clients while acting as their Buyers Broker. The system will start inside the basement or crawl space at the slab or floor level and the 4-5 inch PVC pipe can often be routed up a chase used for other utilities even in two story homes - sometimes it may have to exit a side wall and code allows that. It must not terminate near a window, but should terminate above the roofline. This system is not passive and does not rely on gas to rise - it is designed to pressurize the slab and will have a quiet motor mounted near the top of the pipe which is constantly on to provide negative pressure in the slab so no Radon gas can emit from any cracks in the slab. At anytime the motor stops the system is not working. These suction motors have a long life of several years. Google Radon for more info.
Broker/Owner - Realtor
Professional Buyers Broker
ICC Code Certified Building Inspection Expert
Before I moved to Florida, I had a radon mitigation system installed in the house I moved from. The home was built into the side of a mountain in Valley Forge, PA. Radon is actually quite common in that area, due to the seams of coal in the local rock strata.
The home was a rustic contemporary, with an A-frame at one end, and the rest (the majority) of the house a ranch-style with decks on the main level, and a daylight, finished basement, with sliders to the outside, +below.
The company that did the remediation drilled a hole in the floor, in the corner of the downstairs bathroom (for the intake). A vertical pipe was then inserted. It was not really very noticeable, since it was behind the door. Then the pipe was run into the space between the floors. Next, it was run horizontally to the outside wall. At that point, the pipe became vertical again, and was extended up, above the roofline, where a fan was installed to pull the air to the outside.
Our system was most likely the type that Robert Whitfield has described. It was a relatively simple project, completed in a day or two.
Maggie Hawk, REALTOR
Watson Realty Corp.
Once installed, the company handlign the installation should retest to ensure that the system is working for you. This should be done prior to close.
Good luck - and congrats on your purchase.
Unwavering Commitment to Service - in New Jersey
There is alot of data online regarding Radon. I had a client install a system in the Roswell area and the pipes came up through the house from the basement level. The piping is secure and any radon gas would travel upward through that system and exit through roof vents. No doubt, being sure any mitigation pipe system does not leak is important. A gas will travel upward if it is lighter than air and go to the area of lease resistance which the escape piping provides.
Installing the system outside may have a possible safety feature in reference to a leak, however the problems then might be environmental (sun-ultraviolet, heat and cold) effects on the system over time. Likewise, can you make it esthetically pleasing and not ruin the attractiveness of your home.
I believe an interview with several Radon Mitigation companies would give you experienced and practical answers to these questions. Also call the County Health Care office in your area (likely Fulton) to get their insights.