A Mixed foundation Radon mitigation system. The home has both a 2,000 square foot basement with poured wall and foundation as a well 2,000 square foot of crawl space. The radon system is venting the basement floor and the crawlspace.
One of the common misconceptions among homeowners buyers and even real estate agents is that the manometer measures radon levels. When the home owner, buyer or agent sees a non working manometer at zero they think it means there is no radon and do not realize it indicates the system is not working. It is the responsibility of the radon measurement provider or the mitigation system installer to inform the client on what the manometer actually indicates
Architectural Drawing of Crawlspace Depressurization Radon System Shows the use of schedule 20 perforated pipe and a PVC fitting to support the vent stack to provide radon ventilation for a crawlspace. Not the vent stack must be a least 12" above the roof line and 10’ from any home openings.
While the short term test is really all that is possible during a real estate transaction it paints an incomplete and possibly inaccurate picture of the radon history of the home. Even if the radon test comes back low a new buyer of a home should consider having a long term test performed to determine a more accurate picture of the radon levels in the home during their normal living conditions
The small crack noted in the foundation as seen in the attached picture is an example of how radon gas can enter a home in a slab on grade home. Radon-222 is a gas so it can more through cracks easily.
I read the article on Radon gas. What i found to be a great piece of information was that it would cost between $350-$500. This is a small price to pay to get peace of mind in knowing that you have taken steps to remove radon from entering your new home.
In my image above we can see a recently install radon system. The system meets piping spec of using schedule 40 pvc pipe. There is an error in the installation however. The exit pipe is not 10ft from the window pictured of the house and it also does not appear to extend 2ft above the roof line.
For this section I researched Insulation and energy which discussed air leakage locations. Inside your home though no windows may be open there are many points where outside air can leak in and inside heat/coldness can leak out. The best way to prevent that is to seal all joints and cracks in flooring and corners especially those that lead to the outside with a bead of caulk.
This picture is of a Radon Dynameter made by Radon Away. This device is typically mounted on a radon pipe in an accessible area in order to provide a method to visually inspect the radon system is working properly. If the radon mitigation system installed is working properly, the water levels seen in the Dynameter will not be equal. This indicates a low pressure within the pipe, meaning radon is being continually vented to the outdoors. If the water levels are equal, the system is not performing properly and radon is not safely being vented out of the house.
The image I selected for this essay is of an active radon system. A typical active radon system pulls radon from the homes foundation up through and out of the roof by using an inline fan, often mounted in the attic area. This fan is set up to run continuously, so a constant low pressure is created, pulling radon up and out of the home safely.
This is a photo of part of a radon mitigation fan and exhaust pipe. It is properly located in an attic space and exhausted above the roofline to prevent radon reentrainment. The system appears to be on its own circuit.
Homebuyersand sellers guide to radon. This article reinforces the facts about radon that I have learned in this course. It explains how to test and mitigate radon from residential homes. States basic facts that radon is a cancer causing gas and reinforces the fact that radon is the second biggest cause of lung cancer in the United States next to smoking .
Crawlspaces can have high levels of radon and decay products. Vapor barriers can be an element of a radon mitigation system. However, to prevent harmful gases from leaking through, they must have seams sealed and be sealed to the foundation wall. With these seams sealed, the gases can be vented to the exterior using plastic piping.
Radon and decay products can enter the home in a variety of ways. A graphic, “radon entry into the home” portrays these clearly. It may seep through cracks in basement floors and walls. It may leak through floors above crawlspaces. It may rise through plumbing and ducting penetrations. Efforts to reduce radon in the home should start by sealing the living space from movement of air from below.
The Sub Pump has been properly installed to limit radon gas from entering the basement. The hole has been covered and an air tight seal has been made with the uses of a sealant. The sub slab active system can properly function.
Buyers should have homes tested for radon air prior to the sale of there new home. Radon gas can be dangerous and is one of the leading causes of long cancer. Even new homes pose a risk of radon gas. Newer construction methods can reduce the amount of radon but might not entirely solve the problem. There are effective ways to remove radon but you must first test to see which method will work best.
The above photo depicts the termination point of a passive sub slab depressurization system in the unfinished attic. The system should be terminating at least 1 foot above the roof line. The pipe should also be labelled as “Radon Mitigation” to prevent it being mistaken as a waste/vent line. In addition, there is no electrical box within 6’ of the pipe for future conversion to an active system.
Strategy to Determine Need for Mitigation image from https://www.nachi.org/gallery/
During the course study I was impressed with this particular image as an excellent tool for clearly communicating the need for mitigation to future clients. It is a clear and concise tool for illustrating the order of steps hat should be taken before investing in a radon mitigation system. I will be using this chart often in the future.
An open sump crock is an area for Radon Gases to enter the home. Sealing the crock could help prevent radon from entering the home should the levels be found to be too high after Testing. A solid seal cover is recommended on sumps with below floor piping
