When it comes to radon vent pipe clearances it can be confusing what is and what’s not allowed, what’s safe and what is not. Looking at radon mitigation systems in central New York you will see a wide range of installation methods including the location of radon vent pipes. Very often radon system installations do not follow the EPA or similar radon mitigation standards.
There are several reasons for this confusion including:
- Some radon mitigators install the quickest cheapest system possible disregarding all radon mitigation standards.
- Many parts of country have no codes or regulatory oversight regarding radon mitigation.
- Areas where radon mitigation falls under the building codes there is often confusion due to lack of education on the part of code enforcement.
- Many code enforcement officers simply don’t have time to inspect radon mitigation systems, unless complaints are filed.
- Building codes change from year to year.
- Some of the radon mitigation standards are considered outdated by some radon mitigators and radon supply manufacturers.
Some states are just beginning to look at implementing codes and educating code enforcement officers for radon mitigation including New York State. The EPA and other guidelines somewhat follow the standard codes for plumbing vent pipes which generally are vented above the buildings roof. New York State just raised plumbing vent pipe code from 12 inches to 18 inches above the roof and at least 10 feet horizontal distance from any opening to the building i.e. window or fresh air intake. The EPA radon mitigation standards are pretty general designed to cover a wide range of building situations.
Radon Vent Pipe Clearances – Example
In following scenario, following the EPA standards it would be fine for a small single story house 1.) to be vented above the roof line as close to the ridge as possible, 2.) terminating at least 10 feet above the ground. This would be considered safe even if there may be a high rise building right next door with windows and balconies many stories high with the closest window only 10 feet and 1 inch horizontal distance away from the radon vent termination and with many more windows above that. This scenario would meet the EPA safety standard for the high rise occupants, figuring that the radon laden air would dilute to a negligible amount after traveling less than 10 feet.
Practical Application of Safe Radon Vent Pipe Clearances
So practically speaking, if there are no specific codes that require otherwise, in the above high rise scenario those same clearances should be perfectly safe to apply regarding your own home. As long as you meet the safety distances from openings to the building and direct the radon gas away from the home so as not to cause moisture damage, in some situations it may be preferred not to vent above the roof line.
Practical example: Lets say a radon system is located on downwind gable end of a 2 level home and the height of the roof ridge is 35 feet above grade and there are no windows at all on the entire wall. By the way this is a fairly common situation I run into. Say there is an exterior chimney on the center of that wall and you want to run the radon vent pipe on the rear side of the chimney so it is not seen from the road. It should be “safe” to terminate the radon pipe 15 or 20 feet above the ground (which exceeds the 10 foot minimum height standard). It is also well over 10 feet horizontal distance from any windows or vents to the sides or above including any soffit vents that may be present. Even though the radon pipe does not extend “above the roof as close to the ridge as possible” it discharges the radon gas in a safe way, while reducing the vent height by 15 to 20 feet. In this example, even though it does not technically adhere to the EPA radon mitigation standards, it does adhere to the heart of the safety issue. It also has the benefit of shorter vent height which will improve the performance of the system and make it easier and safer to maintain and service, verses running the pipe another 15 or 20 feet to meet the letter of the EPA standard.
In this photo to the left you can see a radon vent pipe that terminates safely about 13 feet above the ground and greater than 10 feet horizontal and 2 feet above the closest window. The top of the vent is angled at 45 degrees to the moist air does not cause moisture damage or mildew stains on the siding. This homeowner preferred this installation verses running the vent up the soffit, around the gutter and above the roof.
Below are some pros and cons pertaining to radon vent pipe clearances explained that should help you in determining what might be best for your specific situation. I like to weigh out all the options, talk it over with the homeowner and decide what will work best for their needs.
Advantages of shorter radon vent pipes when safely installed:
- Shorter pipe is easier to install and saves on cost.
- Shorter pipe makes it easier and safer to maintain vent and change radon fan when needed.
- Shorter pipe will have less condensation and related freezing issues that can hinder fan performance and shorten fan life.
- Shorter pipe will have less resistance which leads to better fan performance and lower radon level.
- In many situations a shorter pipe will look better aesthetically.
Disadvantages of shorter radon vent pipes:
- The shorter the pipe the louder the air discharge noise, this can sometimes make a difference.
- If it terminates lower than 10 feet above the ground it could be a potential safety hazard.
- If it terminates less than 2 feet above a window within a 10 foot horizontal distance it could be a potential safety hazard.
- If it terminates less than 10 feet horizontal distance below a window it could be a potential safety hazard.
- If it terminates less than 10 feet horizontal distance below a ventilated soffit or other air vent it could be a potential safety hazard.
Including contractors who say they strictly adhere to the EPA Mitigation Standards of Practice it is very rare that any radon mitigation contractor will run the vent pipe up the center of a gable wall in order to terminate the vent pipe above the roof as close to the ridge as possible – as per the EPA standards. I explain the practical and safe application or radon vent pipe clearances and if that is what people want, I will be happy to do that. They may want to be extra safe, but at the same time I explain it will be more difficult to service, less aesthetically pleasing, and sometimes may cost more.
A shorter pipe can usually be easily extended if decided at a future date to vent higher up above the roof.
Side wall venting. Many gas appliances vent through side walls now instead of chimneys. One of the newest fans designed specifically for radon mitigation vents directly through the side wall similar to a dryer vent, using an aspiration hood to mix and disperse the radon gas; it follows the same clearances as high efficiency gas fired heating appliances that also vent through side walls, they are allowed to at least 4 feet directly below a window opening. Additional clearances to doors and vents also apply similarly to the gas appliance sidewall exhaust vents.
Hi i bought a house and i just had a radon system installed and he just put in the box and charcoal to do readings to see what the radon level dropped,to. My initial reading was 4.1.
I have a raised ranch. He tried to install in garage but communication was not as good. He put in only unfinished area in laundry room venting out back of house which is middle of house. The pipe runs up and when he gets to sofit he has elbow type pipe to go around that and then up over about 18″. When i looked at it i am uneasy because its not 10 feet from windows its between two windows and maybe less than 2ft diagnally. To me it looks,especially close to my bedroom window.i hace cat with respitory probs which she has meds and inhaler. She sits i window all the time. plus if im sleeling i am there 8 hrs each night i dont want on windy day that gas seeping in. I really dknt like it and am very uncomfortable about the way pipe so close to window. I am very u easy. I also have my deck from upper level and just see.s pile is too close where i am concerned if sitti g on there the gases are right there. What should i do i will not be at ease living there with the way it is. Thank you
Hello Mary Ellen,
From what you have described, this is similar to the picture at the top of this page and it sounds like the radon vent pipe termination should be safe. Even if the radon pipe is right next to the window, as long as it terminates at least two feet above the upper most opening of the window it should be fine. Remember that radon disperses very quickly into the air and that the radon is being blown forcefully upward out of the pipe even further away from the windows below. Even though this installation may not look pleasing, as long as the end of the vent pipe is two feet or more above the windows, it is within the radon mitigation standards set by the EPA for safe venting, and therefore should be safe. I hope that helps set you at ease.
It seems different jurisdictions have different requirements. Ohio code language clearly states the discharge termination has to be above roof edge. See here: http://www.odh.ohio.gov/~/media/ODH/ASSETS/Files/rules/final/3701-60%20to%20-69/3701-69/3701-69-08-Apdx.pdf
Hi Tom, closing on a house this week that tested for high radon. Installed active mitigation system today and will get test results back wed. The radon vent exit above garage but it is about 3 ft from bedroom window and in line with it. Sounds like this isn’t up to code and risk radon seeking back in (even if we keep window shut?) how much to get someone to re route it to get it up to code?
Also, is it normal to open all the windows a day the day the system was installed? Worried they are trying to get the readings low for tomorrow test.
I am looking to purchase a two story home with an existing radon system. The exhaust is at the back corner of the house and is turned directly toward the ground (approximately 4′ off the ground). At the adjacent corner is the stairway down to the basement door (12′ below the exhaust & about 10′ away linearly.) This seems like a bad idea to me, as the stairway could act as a “trap”.
I haven’t seen anything that says exhausting 4′ off the ground is ok, so I assume that needs to be addressed. But, I have a follow-up question:
Is simply raising the height of the exhaust point and possibly converting the angle sufficient?
Hello Brent, without seeing the house, it would most likely be a safety improvement to get the radon vent termination at least 10 feet above ground level (EPA minimum height allowance). You would also want to ensure it is not venting below any windows that are within 10 horizontal distance. The EPA radon mitigation standards recommend installing the vent termination above the roof edge near the highest point of the roof; however this is often not practical and usually ends up being vented somewhere lower. Once you get beyond 10 feet distance from the radon vent termination, the radon gas will be mostly dispersed and no longer a concern; you can even vent right next to a window as long as the termination is 2 feet or more above the opening of the window.
Hello Joe. It is ok to air out a house prior to a radon test and really makes no difference as long as the house is shut up at least 12 hours prior to the beginning of the radon test and remains closed for the duration of the test. The homeowners can come and go out the doors, but keep the doors closed (how you would use the house in freezing weather), but doors and windows should not be left open during the test.
If that window opens that should be corrected. If that window does not open it should be fine. Radon vent pipes can terminate next to or below windows that do not open. Cost to move the pipe would totally depend on who does it and what they charge which would be determined by what is required to move the pipe and how difficult it is to access the attic spaces. I would think a rough estimate of cost to move the pipe would be $250 to $500 and may also require patching some holes in the walls after he is done.
Hope that helps.
Yes Mike, the EPA radon mitigation standards are from about 1994 and no longer current, since there are a few other national radon associations that have similar and current standards. Many parts of the country have no code or regulation regarding radon mitigation, this is where the national standards of practice apply. Local codes always take presidence.
Hello, I recently got a mitigation system installed on my new house. It is a single story ranch but has a crawl space and cellar. They installed piping in both areas. It comes out the side of the house but only goes as high as the ease. It is under the roof ease and there is a window less than two feet below. If I wanted to extend the piping I how would I go about doing that. I read in your post it isn’t too difficult to extend the piping. Thanks!
When running the vent pipe up does the 10 feet horizontal clearance take into account a window that is around the corner?
Hi Jake, the 10 foot horizontal distance is the minimum distance required from the exhaust or vent pipe termination (where the air blows out) to an opening into the home i.e. a window or fresh air vent. So if the vent pipe ends two feet horizontal distance from a corner, there should be no operable windows closer than 8 feet horizontal distance around that corner. Hope that helps.
I am reviewing my options for running my radon vent pipe and wanted to ask how far from a working fireplace \ furnace chimneys should the vent pipe be. I am concern of gases from the vent pipe making their way down the chimney when not in use and also the possibility of gases from the vent pipe that could be flammable..
Hi Frank, the 10 feet horizontal distance is good if the vent terminates to the side of or below the flue opening, if the radon vents in an upward direction, and is above the flue vent it can be right next to it as long as it terminates at least 2 feet above the flue vent opening.
Sorry for delay in answering this. You need to figure out the type and size of vent piping that was used and get the right pieces. If the pipe goes to the edge of the eve or the face of the fascia, all you really need is an 90 degree fitting and a section of pipe to extend above the top edge of the roof 12 to 18 inches depending on you local code. NY State now requires 18 inches above roof for plumbing and radon vent pipes.
I have an existing system that has the vent pipe on a side of my single story house. There are no windows on this side of the house. However, the vent pipe terminates below the eve with a 90 degree elbow. There are soffit vents very near and immediately above the elbow. Should this be extended with a horizontal pipe, then another elbow to turn vertical, and then another piece of straight pipe to a point above the eve? I don’t think that would look vertical good but I am concerned with radon accumulating between my ceiling and roof. Also, should it have some sort of rain cap?
Hello. Is there any problem with installing an inverted U tube at the top of the exhaust vent? I am concerned about the falling debris – specifically seeds from the sweet gum trees around my house. These seeds are about an inch in diameter and weigh about 4 grams. If adding an inverted U is not an acceptable solution, is there any other solution that would prevent the seeds/leaves from entering the vent? Thanks.
I have a ranch home. I plan on running the pipes through the basement out to the garage and vent out the roof. The garage has windows and a standard access door near where the roof vent would be. Are garages exempt from the regs because it is not “living space?” If I move the in the vent in the opposite direction I’m to close to the living space house door. Also, I’ve heard not to use any type of cap on the roof vent, yet I see vent pipe caps advertised ( to keep out rain/snow/debris I guess) Thanks
Tom, I just moved into a new construction home. I asked the builder to install a passive radon mitigation system during construction, so I could have it upgraded with a fan should I find a radon problem, which I have. The builder used 3.5″ ASTM D2949 schedule 30 PVC and it exits to the exterior a few feet above grade (didn’t think to ask for it to be run through the attic, shame on me). I know schedule 40 is preferred. Do you think I can get by with the schedule 30? The home is in southeast Michigan, so cold winters, and pipe is on the sun side of the house, so I am concerned about deterioration, cracking, etc.
hi i just had a mitiagation system put in i have a ranch with a hip roof it was put at the lowest point my question is .. is it dangerous to be outside near the system now that it is pulling high levels of radon put of the ground
I never see vent covers to keep rain out of radon vents is there a reason for this? It seems that water in in a good down pour would be damaging to the fan and but water under my house.
Is is okay to vent the mitigation system exhaust into an unused chimney that is in the center of the house and extends well above the highest point of the roof which is also in the center of the house. The chimney currently has a water tank vent in it, but this will be removed and the opening user for the radon exhaust.
We live in a neighborhood with high radon levels and have a system installed in our home. The prob is our new neighbor just put a system in and it vents on the side of the house near our childrens play area. What makes things worse is our property is at least 4 feet higher than theirs so we are conerned thst the radon gases would come in our childrens direction
As long as the vent pipe terminates at least 10 feet above the ground, and it should, there should be no issue, radon gas disburses very quickly into the atmosphere. If for some reason it does vent close to the ground, as long as your children are at least 10 feet away from the termination point – in a horizontal direction – the radon will have disbursed.
The only safe way to use a chimney flue or chimney of any kind, if it has been abandoned, is to use it as a “chase only” in which to run your schedule 40 type PVC pipe. Making sure all pipe joints are properly primed and glued so there is no chance of radon gas leaking. This only works if there are no offsets in the chimney and can be a tricky process on a long chimney, piecing the vent together as you feed it into the chimney chase from the top or from the bottom.
Good question, I get asked this a lot. Water will not harm most good quality “radon” fans. I tell my customers, you could dump a 5 gallon bucket of water down the pipe with the fan running and it would not harm the fan. With a 4 inch pipe diameter open to the sky, in a torrential downpour I doubt you would ever get as much as a quart of water in the pipe and remember the air is blowing out quite forcefully in most systems so light rain would not even enter. The fans have sealed bearings and are rated for high moisture environments. Some radon systems can pull upwards of several gallons of water moisture from the soil each day, depending on the moisture level in the soil and size of fan; this makes for a very wet environment inside the radon fan and vent piping. However proper installation is important whether you have a rain cap or not. If the vent pipe is properly installed, meaning the proper materials used (typically schedule 40 PVC pipe), all the pipe joints properly sealed with PVC primer and glue, and all the vent pipes back pitched so that any condensation build up or water from the top of the vent pipe will all drain back down the vent through the fan and into the ground, then there are generally no problems. Problems arise when pipes are not properly pitched, then the water can pool or collect or completely block the flow of air if there is a trap built into the vent pipe. The reason most of my systems do not include caps is that the cheap caps block the air flow quite a bit and can reduce the effectiveness of the mitigation. I’ve see some systems that did not get the radon below 4.0 pCi/L and by just removing the rain cap the radon levels dropped significantly. Good quality low restriction caps cost about $20 to $35 and most people don’t want to pay it. I offer screened rain caps as an option. In my opining the best reason for a cap is to keep critters out of the pipe for low air flow situations or in case the power gets turned off. I have taken quite a few dead birds and squirrels out of radon fan housings. So I usually just install a stainless steel screened cap, that is open to the rain.
Yes it might be dangerous if you are standing on the roof or on a ladder above the radon vent pipe and you could feel the air blowing in your face. As long as the pipe vents above the roof and you are not on the roof you should be just fine. I’m assuming your radon vent pipe termination point is about 10 feet or more above the ground.
I’m not familiar with schedule 30 pipe, here in NY we have ready choice of schedule 20 or 40. You could probably easily convert to schedule 40 PVC pipe with an adapter or rubber coupling where it comes out of the wall and use schedule 40 for the rest of the exterior system.
Garages are not a living space, so you can put the radon fan inside the garage or the attic of the garage if there is no living space above the garage. On the roof you want to follow basic pluming vent codes for the radon vent pipe termination. It should be at least 18 inches above the roof surface and more than 10 feet horizontal distance from any window or vent opening into the home. Most of my systems do not have caps for cost reasons, however I do recommend the type that have heavy duty stainless steel mesh and are open to the sky. Rain is not a problem but critters can be in some situations.
That should be fine, make sure you have enough clearance above the opening so as not to unduly restrict the air flow.
You could extend with horizontal pipe to point flush with the fascia alone for a cleaner look, or you could then add a 90 and extend up above the roof edge 12 to 18 inches. Rain cap is not needed but a screened cap will keep debris and critters out if that might be a problem.
Tom, all the recommendations mention 2′ above or 10′ away from an operable window. But what if the pipe is 10′ above grade, but within 8′ (horizontally) and 4′ below a second story window. Assuming that radon is a heavy gas that disperses quickly, wouldn’t this be an acceptable method for terminating the pipe?
The assumption that radon is a heavy gas may be true, however the wind is much more of an issue. If you have 10 or more feet from the termination of the vent pipe to where the window opens, you should be fairly safe. It is best to vent above the roof if possible and above windows if possible. In some areas there are radon mitigation standards that must be adhered to in order to be acceptable. It sounds like you are pretty close to the acceptable distance, if you are not sure you could check with your local building code officer, they may or may not be able to help, many are not familiar with radon mitigation system standards.
You could also do your own testing to make sure; to best perform the testing you would need an electronic radon monitor (about $130), that way you could do multiple tests and get instant testing results. Test that room with the window open and closed in various weather conditions, and see if there is any raised radon levels with he window open as compared to being closed. Hope that helps.
How many nineties can be in a radon system run? The system they put in my home, the pipe runs in the middle of my stone home. Can I put a couple of nineties in to extend to corner of home and then up?
Each ninety degree fitting added to a radon vent pipe reduces the air flow a significant amount. So we normally try to keep them to a minimum. My average system includes a total of 2 to 4 ninety degree fittings and some times more. It also depends on what size radon fan you have, and how much air flow you are getting. Most systems you could probably add a couple of nineties and it will still perform fine, however on some systems the additional resistance caused from the addition of one or two nineties may cause it to no longer be able to reduce the radon to an acceptable level. So I would say go ahead and add them, but then you should re test the radon level to ensure the system is still working good enough, if not you will need a more powerful fan or remove the nineties.
Regarding the added nineties, I would add that the additional lengths of vent pipe will likewise reduce the flow of air also.
We recently purchased a home and had a radon system installed shortly after taking ownership of the property. I was not home at the time of install, and communicated with the installers via phone. We decided that the best place for the system was the basement wall that has exhaust for the furnace and piping for the A/C unit, as the masonry chimney for the upstairs fireplace was on this wall as well. The piping was run along side the chimney to just above the roof line. It is a cape cod with a very pitched roof, and the pipe runs up the wall, along the chimney (which is positioned at the center of wall) to highest point at the top of the roof line. I had two questions for the installers. 1.) They used down-spouting instead of PVC and said that was acceptable. I have never seen down-spouting used in my area (PA) before. And 2.) There is a second story window that is very close to the chimney and thus close to the pipe running up the side of the house. The down-spouting actually almost touches the chimney on the left side and does touch the window trim on the right. I asked for aesthetic purposes if we could run the pipe from the system to just below the second story window (which is greater than 10ft in height) and then put an elbow (90 decrees or so) so that the vent pipe would be positioned away from the house. This would look 100 times better as the pipe would naturally end underneath the window instead of running right up against on the trim. I was told that was not an option. Is there any danger if I cut the down-spouting off under the window and put an elbow or extension so it points out away from the house?
There may or may not be safety issues, it would depend on many factors, such as how much force the air is blowing out of the pipe, the level of radon in the exhaust air and the negative pressure if any inside the house, direction and speed of the wind blowing etc. It is not recommended to terminate a vent below an operable window. If you do not open the window it should not be an issue. With that said I know PA is quite strict about following their radon mitigation standards, perhaps more so than any other state.
Hi there, I’m wondering if you can help me. Our neighbour recently had a radon exhaust vent installed about 1.5 feet above ground. It runs quite loudly 24/7, but what concerns me more, is the fact that their home has about a 5 ft clearance from our home ( on the same side that our windows open). Other than the noise, I’m very concerned about the safety of the exhaust from the vent. Is this something I should be concerned about? I’m having a very hard time finding answers and of course, they’re saying it’s totally safe. Any advice you could give me would be greatly appreciated. Thank you
Thinking about installing vent cap. Called company who installed and they advised not to. I had a concern with several types of leaves entering system. Company advised not to be concerned, as unit fan will chop up the leaves , and they will fall below. Also stated vent cap would restrict air flow. I agree with that one. Any input would be greatly appreciated.
Hi Tom – i’m currently building a new home (central NY), and we have put a radon mitigation system in. My question is in regards to the venting pipe. I would like to vent the radon pipe out from my basement, go underground about 40 feet and then go vertical in the woods (out of sight). I have no idea if this would be out of code or limit the venting flow…we ran 4″ pipe. Any insight would be greatly appreciated. Thanks.
Hi Tom, I have an attic fan on my roof. If I have my radon vent pipe 4 feet away from fan, would that be a problem? Would I need the pipe to be 2 feet higher than the opening of the attic fan?
Hi Tom! I wanted to know how to determine the qualifications of the contractor? I need to test and mitigate radon in my house. I Chose several services, and I try to compare them. On what grounds is it possible to determine the best? Is it possible to have equipment or technology standards? Thanks for the answer!
Hello. I just did s First alert test an my result was 29.5 cpilf. in my basement colonial home. i obviously need a system. I also have an attached garage with a family room on a slab. Do i need to worry about radon under that slab.
Can i have a pipe coming out from the slab and meeting the pipe from the basement then have the fan outside to temove the radon or do i need 2 fans. thanx steve
Good evening Tom, I currently have a radon removal system which is mounted externally below my deck, with the fan mounted approximately two feet of the ground. It is vented thru my deck,into the soffit and then extends thru the roof. I am in the process of siding and do not want to have the vent pipe running along side the house anymore. Is it possible (or feasible) to re route the vent pipe horizontally under the deck and terminate approximately 16 feet away from the home?
Thank you for you assistance.
I have seen this done several times, in NY State at this time there are no hard fast rules for radon pipe vent placement and it varies by localities local code enforcement of which most areas have no enforcement at this time. NY is just starting to teach code enforcement about radon mitigation. You need to keep in mind the basic safety criteria for radon vent discharge, it should vent at least 110 feet above the ground and more than 10 feet horizontal distance from any widow or door openings into the home if discharging be level with or below those openings, or should be 2 feet above those openings.
One more note, you need to be sure the pipe is back pitched toward the fan so condensation will drain and do not put any traps into the line which will hold water. 16 feet is quite a bit, especially if you will angle upwards after that so if the vent is longer it will have additional resistance of air flow, it may not perform as well as with a shorter piece of pipe.
Thank you Tom. From what I am reading I then could run a vent line horizontally from the fan going out ten feet away from the home. Would I also then have to put in an elbow and go vertical for any length?
It depends on the height of the deck and its proximity to walking or children’s play area, etc. What I have done in the past is to terminate horizontally if it is well above the ground level away from where anyone would be walking. In other cases I have angled upward 90 degrees along a railing support and terminated up higher, you also need to be aware of people on the deck, so radon gas does not blow at them. Noise is also a factor since usually the loudest point is were the air comes out the end of the pipe.
I have a ranch style home with a basement built into a hill, with no attic. From the front it looks like a one story home, but from the rear it looks like a two story home. Can the radon fan be installed in the basement and then vented up through a closet to get to the required height above the roof?
What type of fan would you recommend?
Having had a home that had a radon level over 75 I can tell you all this paranoia about vent location is unnecessary. The truth even at 75 once you install the vent you can put the meter or detector right inside the airstream of the vent and your reading will be the same as the rest of your basement. In my case I got it down to 1.5 to 2.5. The downside while any vent location to the outdoors will work perfectly fine and safe, when you go to sell your home know one is going to understand the science of why this is so . I’m sure I will raise the ire of some contractors on this. I can only say is go ahead and test my claim for yourself by testing the air in the exhaust pipe after the system is up and running for a day.
Tom, you might have answered this already; I got a radon mitigation system installed to my house, but when the specialist came in he left a hole on the roof soffit because something obstructed the radon pipe from going through the roof so he added a bend to the pipe and set the pipe through the roof a few inches from the original hole. After that the builder just slapped a soffit vent instead of closing the hole, this new vent is maybe 2 feet below the end of the radon pipe. Do you think I should seal the soffit vent to prevent the radon from going into my attic? should I let it be? how good is the seal on the radon pipes? My mitigation system comes from the basement to the side of the house and then it enters the soffit to come out on the top of the roof. Thanks!
I just had an HRV system installed. The exhaust vent is about two feet under a double bedroom window. It seems like the radon exhaust would come into the windows if they were left open. Should I be concerned?
If the radon vent pipe terminates 2 feet above any opening into the home it should be fine.
I have measured it several times on different systems with different types of monitors. It depends on the type of radon detector you use. Most equipment that gives instant readings are not actually measuring radon but measures different types of radiation. The equipment I use does detect raised levels of radon at the vent pipe termination, of course it does vary depending on the amount of radon coming out of the pipe. The radon does disperse quite quickly once it is in the open air. Sure some people may be somewhat paranoid, but it is usually recommended to err on the side of safety and that is kind of the reasoning behind the radon mitigation standards. They are general standards to help prevent health risk situations in certain circumstances. Every house is different and the mitigation standards do a pretty good job of keeping the systems safe for the most part.
Sure that should work very well. In NY we any roof vents have to be at least 18 inches above the roof and more than 10 feet horizontal distance from any opening such as a window.
My mitigation system looks almost identical to the picture at the top of this page except the eave extends about 2 feet away from the house and the top of the window is where the eve begins. The distance from the top of the window to the end of the vent is less than 2 vertical feet and closer to 18″. Does this still meet code requirements? Thanks very much.
We have a ranch home with a crawl space and basement. We have a radon system in place. My question is about the pipe that is in the basement. How far away from that pipe should we store things? Does it need a certain clearance around it to be effective?
Hello Lynn, no clearance around pipe is needed. You do not want to break the pipe, it should be sturdy and quite strong if they used schedule 40 pipe. IF they used schedule 20 pipe it is much thinner but still quite tough and would not break unless you abuse it, hit with a hammer or baseball bat.
is it possible to use a dryer exit with schedule 20 pipe?
I understand that venting radon into the plumbing vent system is against code but no relevant reason for this is ever given. If the attachment point for the radon exhaust system is in the attic and well above any plumbing fixtures what would be the problem?
Radon should not be vented in a dryer pipe along with the dryer. In the same way you would not vent your toilet or sewage waste pipe in your dryer vent. You can use schedule 20 pipe if the joints are glued, but that light weight pipe should only be used inside wall cavities or in attic or crawl spaces where there is little chance of it becoming broken. Schedule 40 pipe is probably at least 10 or 20 times or more stronger than schedule 20 pipe.
I can think of three reasons right off the bat. 1) Safety; 2) To avoid confusion; 3) Plumbing vents are for plumbing systems and radon vents are for radon systems, those two should not be combined for a multitude of potential reasons. For one thing the plumbing vent most often, pulls air “down” into and all through the house to assist the water flow when draining. If you had an open trap for some reason the radon gas, along with sewer gas could be pulled into the homes living area. IF it is tied into the plumbing pipe most people would assume it is a plumbing drain and or plumbing vent pipe. I have seen a few times where people mistook radon vent pipes for plumbing pipes and added a new sink or drain that tied into the radon pipe; this is a big problem, now you are using the radon vent pipe for a plumbing drain, the waste water just drains into the ground below the slab at the radon suction point, and depending where it ties in, it will also drain right through the radon fan, which isn’t a big deal if it is just water, but is a big deal if it contains say toilet paper or more.
Has anybody ever heard of venting underground, away from the house, about 15-20 feet? One company recommended this way for my house. They say they do this for historic houses so that it looks better than an exhaust pipe up the side of the house, sticking up 2 feet above the roof line like a periscope. I’m worried about the break down of the pipe, being underground and all, and about the safety of actually venting radon horizontally rather than up and into the air.
Thank you for your help!
I have done similar options for similar reasons. If it is done correctly, it can be effective, safe and long lasting. Must use solid core schedule 40 PVC pipe, same that is used for sewer drain pipes, with care it can be directly buried. It is important that the pipe has the correct amount of back pitch, same as required for a plumbing drain, but must slope back towards the house to drain back into the suction point below the slab or crawl space. The exhaust point of the vent pipe termination should be at least 10 above the ground or where people will be standing (in near a deck or something.) As with any radon mitigation system if the installer cuts corners, is sloppy or uses improper, inferior materials there will likely be some safety or operational issues after the installation or at a future date. Hope that helps.
Thanks Tom for your reply.
What if the exhaust point of the vent pipe termination is just a few inches out of the ground with two 90 degree elbow joints? This would be 15-20 feet away from the house.
Or do you recommend having the pipe go 15-20 feet away from the house (underground), then one 90 degree elbow, and up 10 feet, like along side a fence or something?
Thank you again!
It sounds as if the pipe is solid pipe only for 5 feet or so (underground), then becomes perforated pipe for another 10-15 feet underground, so this would help with condensation? It then comes out of the ground 4-6 inches, away from where people are at. So there will be little air coming out of the pipe at the end, because of the perforations. They say they have been very successful with this method, so was wondering your thoughts. Would you do it this way, or just stick with the conventional up the house and above the roof line?
Thank you again Tom!
My home was built in 2012 and has a sump pit with two 2″ PVC pipes coming off side up through concrete. I know the lower one in pit with a 10′ rise that extends to ceiling then put back wall is to be connected to a sump pump. I assume the other pipe might be for radon venting (it starts inside pit near top, with about a 6″ stub above floor level). Would this 2″pipe be adequate for venting radon if I extend to outside and vent per 10′ above ground, 10′ away from and 2′ above window, with a fan attached? I plan to attach a sealed cover on pit and install a sump as well.
Possibly. It is hard to say without seeing the installation. 2 inches is a little small, most radon fans require at least 3 inch pipe for proper air flow, but if you have dry clean gravel and footer drains below the floor 2 inch may work.
Thank you for all of the information. My question is about the placement of the intake pipe in the crawl space. We have a crawlspace and a good vapor barrier across the whole area. Our radon reading is 8.9 and I would like to install a mitigation system. It seems like the easiest location to suck from under the vapor barrier is next to the wall so I can vent it right out. But would it be more effective to put the intake nearer to the center of the house and run pipe along the crawlspace and then out the wall? Thanks!
It depends on how the vapor barrier is sealed at the wall perimeter. If it is not well sealed – air tight, you would be better off taking the suction point near the center verses the perimeter. If you would rather take if from the side, just make sure it is sealed very well so you don’t loose a lot of suction at the floor to wall joint.
Thank you for taking the time to answer all these questions! I found the answer to mine.
Tom, I’ve read the majority of the questions and your responses but have not see an answer to my question. My 3 inch radon exhaust exits thru the roof vertically about 2 1/2 feet from my furnace’s 2 inch fresh air intake. First, is this too close and if ok which should be taller and by how much? Furace’s exhaust vent is between these two. Thanks in advance.
Tom, my concern with the above question is the moist radon gas being exhausted close to the furnaces burner intake vent. Could this cause an icing/blocking situation during winter’s cold months.
Hi Ron, That seems unusual from what I’ve seen around here. Normally furnaces do not have fresh air intake from the roof. Following the standards of practice the radon vent should not within 10 feet horizontal distance from a fresh air intake or opening to the home, i.e. window, or door. If the radon vent is closer than 10 feet horizontal distance, it should be 2-1/2 feet higher that the opening of the window or air intake vent. Hope that helps.
Yes it could.
Great information – thank you.
I’m unclear about the discharge requirements.
We have many windows and the best place for a vent pipe is behind the chimney. That puts the pipe around the corner, about 6-7 feet away from the nearest window. It will, however, extend about 18 inches above the roofline which is at that point about 5-6 feet above the top of the window plane. Is it two feet above or ten feet horizontal or is it two feet above and ten feet horizontal from a window?
I’ve also seen reference to needing a separate exterior (for exterior blowers) power switch and an EPA standard for a screen over the pipe. Is that correct and what kind of screen?
Hi Steve, if the vent termination is two feet or more above any window or vent openings to the dwelling, the horizontal distance does not apply. Screen only cap should be 1/2 inch stainless steel hardware cloth type screen. Beware of rain caps that very often reduce the air flow and efficiency of the system. Exterior electric shutoff may be required depending on the size of the fan and local codes. Get the amperage rating for your fan and check with your local code enforcement.
So when I bought my house the sellers had to install a radon mitigation system. And All of the piping is 6″ diameter PVC. Is that a normal diameter? It runs all the way to the roof in that diameter and vents out on my garage’s roof. This past winter, we had a lot of water enter the exhaust; to the point that the rubber boots around the fan motor were weeping water. My question is: can I legally put a roof cap on this vent to keep out moisture and animals?
If anyone is from Ontario, Canada, and requires professional installation of a radon mitigation system, give Simon Air Quality a call. We are certified by the C-NRPP and fully insured.
I have mid roof intake air vents and a exhaust ridge vent for attic ventilation . What if any clearance planning do I need to consider on running radon exhaust vent pipe outside on gable end of house for proper mitigation.
Hi Tom. Thanks for this article. Are you able to tell me how much it approximately costs to extend the radon gas pipe so that it vents above the roofline? We had a home inspection for a house and was told this issue needed to be fixed. Ours is 10 feet above ground and close to roofline but doesn’t go above the roofline. We are located in Illinois. Thanks so much!
6 inch is larger than normal. Yes you can put on a vent cap, but it should be a free flow type. Try a google search for free flow radon vent cap.
If you are running up the side of the house to the roof edge, run exhaust pipe up past the roof edge about 12 to 18 inches and you should be good. The radon dispurses very quickly.
Depending on how high the roof line is – one two or three story height – you should be able to get that done for about $200 to $300. Most guys will charge about $75 to $150 for a service call, to show up at the house, it is about 1/2 hour of work but requires a ladder long enough to reach the roof, and maybe $50 in materials.
Hi, I am in the process of purchasing a split level ranch home. The seller is installing a mitigation system and the pipe end is about 6 inches from the attic opening (venting). Is this ok?
The US EPA directs that vent termination is 2 feet above any opening to the home, that includes attic vents. Depending on how the vent terminate, either straight or with a 45 or 90 degree angle, and whether it is pointing or blowing in the direction of the vent or not, usually does make some difference. Often installers will sacrifice optimal safety for esthetics on vent piping. Most likely this scenario will make very little if any difference on the indoor radon level of the home. Be aware that the air blowing out of the vent pipe is most often quite damp, so you do not want it blowing on the siding or soffit as it will promote mold growth and dark staining.
Tom: I am about to have a radon mitigation system installed and am hoping it can be installed through my garage roof. There are two windows 10 feet from where I’d like to have the pipe protrude through the roof, but I also have a roof ridge vent about five feet away. The ridge vent would be about two-three feet higher than the radon vent pipe. Would that work?
It should be fine if the termination point is 10 feet distance from the windows, the radon gas disperses very quickly once in the open air. If you want to be extra safe you can allow the the vent to blow the air straight up into the air or possibly add a 45 degree angle to direct it away from the windows and ridge vent. A 45 degree angle usually works better than a 90, because it is less resistance and still directis up into the air above the house.
Most of the questions here have to do with the exhaust end of the system.
My question is the intake end.
How is it conceivably possible that by drilling a hole through a concrete floor that it would ventilate the entire property? There is no air flow beneath the house. No way to draw fresh air through to replace the radon saturation. Anyone who has put there hand on the end of a vacuum cleaner tube can understand what happens when a suction device has no air flow.
It may remove some radon from the immediate area of the pipe but how could it possibly be removing radon from under the rest of the house? And if the pipe is sucking radon near the wall of the house, isn’t it sucking some radon from the exterior perimeter as well? If so, Isn’t that extremely inefficient?
So, from the viewpoint of pure physics, doesn’t it make more sense to seal the entire concrete surface and then use an air ventilation system which draws fresh air from the outside and blows the contaminated air out another side?
Tom, this is a great thread thank you for you support. I have a radon mitigation system that terminates above the ridge of my 2 story roof. However it is closer than 10 feet to a window around a corner. Is this not to standard?
My mother in law just had a mitigation system installed. Metal downspout material was used exiting the fan instead of pvc. The joints were not sealed. The end height was about ten feet. Two feet below the soffit. It may be functional. But seems a bit lazy on the installers part.
I left out the question. Should the installer have sealed the downspout joints?
Hi Chris, I can see where you are coming from, but sub-slab depressurization has been proven as the best way to mitigate “most” homes for a reasonable cost. After much research, trial and error sub-slab depressurization is what is what the EPA, other state radon agencies, many governments of other countries. It is the go to method of radon mitigation in homes for engineering and contracting companies that install residential radon mitigation systems. I would refer you to the details and methods of performing sub-slab depressurization which is off the topic of this thread. A couple of main points, the soil under the slab most homes is contained within the footers which corral the soil gasses below the slab so most of the suction is contained within the footer boundary. Even in dense soil one suction point is sufficient to draw air from the entire footprint of the slab if the fan is sized properly. In some cases I have sealed the floor and installed fresh air exchange to reduce the radon but it is more expensive, and less effective generally and only used when the concrete floor is poured over bedrock and no chance of air movement below the floor, or when there is a gravel or dirt floor basement or crawl space – but even in that case it will only work if the radon level is fairly low to start with.
Usually around a corner if it is more than a few feet there should not be any problem. The standard however would require a total of 10 horizontal feet measured around the corner. In Canada however as far as I understand they do not have any distance requirement at all from windows. The radon disburses very quickly once in the open air. I have tested a few windows where radon vented within 2 or 3 feet of the window opening and no raised radon was detected inside the home with the windows open compared to when the window was shut. I can not say that would be the case with every home and every radon system, but it would probably be generally the case. If you are concerned you could do your own test with window open and closed.
Perhaps. Downspout is usually used for aesthetic reasons, but does not work nearly as well as cellular core, schedule 40 PVC pipe. It is not nearly as durable or insulated as well. If you’re in a colder climate, you can get significant ice build up issues with downspout, any moisture leaking at the joints has potential to make quite large ice sickles.
All radon vent pipe joints should be glued so they do not leak and do not come apart.
We had a radon pipe installed when they built the house 25 years ago and the pipe comes out of the roof overhang. The new buyers want the pipe to come through the roof. What was that entail and how much would it cost?
Our radon extraction vent tube is about two feet above our air conditioning unit. I’m concerned that the air conditioner air intake is pulling from the radon tube. Is my concern rational? Thank you
Our radon exhaust pipe is about 12 inches above our air conditioning unit. Is this reason for concern as the air conditioner is pulling air in to disperse throughout the house?
There is not enough information give for me to quote a price, I would need to see pictures of what you are talking about. For a contractor to make a roof penetration for a radon pipe to extend up through the soffit, would probably range between $200 to $500 or more depending on roof cover materials, height of soffit ect. You should get some quotes from local contractors.
I’m not sure if you’re talking about a window air conditioner or not. If your are concerned it is best to conduct a radon test to determine if radon is getting in at that point. Normally radon vent pipes should be terminated above the roof line to prevent it from getting back into the house.
Any vent pipe termination should be at least 2 feet above any opening to the home.
Thank you for your reply.
Re: Aug. 10, 2018 “I’m not sure if you’re talking about a window air conditioner or not. If your are concerned it is best to conduct a radon test to determine if radon is getting in at that point. Normally radon vent pipes should be terminated above the roof line to prevent it from getting back into the house.”
Our vent pipe termination is located above our ground-mounted air conditioning unit, not a window unit. We will do another radon test and work with the installer. Most information that I read suggests termination should be above roof line. Thank you
Thank you for all your answers. There’s one question I have for which I can’t get any Google answers yet:
Can I run my radon suction pipe from the basement into the the wood-framed chimney chase, up to the attic level, and from there into the attic? The radon fan could then be placed in the attic, with a vertical vent through the roof. This way, I could avoid running the radon suction pipe along the outside of the house.
The wood framed chimney chase already accommodates one metal chimney for the gas furnace, and another separate metal chimney for the decorative gas fireplace. There’s still plenty of space inside the chimney chase for adding 3″ or 4″ PVC tubing. It would just be a straight run of PVC pipe to get from the basement past the ground and first floor into the attic.
Are you aware of any issues with adding a the radon suction tube (3″ PVC tube) into the existing chimney chase?
Hi Tom! Could I route a 3″ PVC radon suction pipe from the basement through the wood-framed chimney chase into the attic? The radon fan could be placed in the attic that way, and the radon suction pipe would be out of view.
The chimney chase is a typical wood-framed chase which is built along one exterior wall of the building. It already houses two metal chimneys, one for the decorative gas fireplace, and one for the gas furnace. There’s plenty of space inside the chase to accommodate another chimney or PVC pipe. It would be one of the easier ways to get the radon suction tube from the basement to the attic.
What are your thoughts on this?
Probably if there is enough clearance to maintain proper spacing for fire safety between vent pipe and chimney pipes. PVC pipe is quite flammable. The type of chimney pipe determines the amount of clearance needed. Should be labeled on the chimney pipe somewhere. YOu could check with your local code enforcement to be safe or sure.
What should my radon level be after a mitigation system is installed? We just had a 24hr reading a week after the new system was installed and the average is 0.78. Thanks! This feed has been so helpful.
Thank you for your years of advice, and for posting everything so clearly on your website!
I do have another question: We’ve installed a 4-in radon vent pipe under our basement slab, and extended the run straight up (no bends) through the 2nd-storey roofline. Active system, with fan installed in the attic. There are no nearby windows, and the vertical radon pipe terminates 18inches above the roofline at the point of roof penetration, but it rests only about 5 ft away (horizontal distance) from the roof’s gable ridge vent (which is “above” the termination of the radon pipe). Prevailing wind direction could often sweep across the vent pipe end up towards the ridge vent. Does this sound like a problem to you?
Hi Lindsay. The lower the radon reading the better. Usually if it is below 4.0 pCi/L that is considered acceptable, however below 2.0 is ideal. You reading of 0.78 is less than 1.0 which is just a little higher than the average outdoor air radon level which is .04. Most people would be very happy with a radon level that low in their home.
FIRE SAFETY – PVC pipe is a petroleum product that is quite combustible. You would need to check with your local code enforcement, if it is even allowed. If it is you need to keep fire safety in mind, to make sure you have proper clearances and use fire stops at any fire wall pipe penetrations. It would most likely require a permit and inspection after installation to make sure it complies with fire safety code.
Probably not. Most of the time the ridge vent is designed to exhaust attic air; fresh air comes in through soffit and or gable vents and rises up and exits the ridge vent. Additionally radon gas disburses very quickly and in most cases would have a hard time getting in any opening in a house that is 5 feet away.
Hello Tom, I am a Construction Manager for a soon to be constructed 4,100 sq. ft. Head Start. My question is, for such a large footprint, are there more than one horizontal vent stacks recommended? Would two vent stacks compete and mitigate each other if connected to the same system? What is the cap on square footage for a single radon vent system? Would two separate systems with two different vent stacks be recommended for two halves of the same building? Or even three systems for a larger square foot building?
Hello, I am wondering about my neighbors vent tube. It looks like the top picture in this page. It does not extend above their roof. It is 2 feet above windows in their house, but they do have an attic vent higher than the pipe. What concerns me is that it looks like the pipe curves and vents right toward my house. My understanding is that I don’t have to worry as long as my house is 10 feet away from the vent? Does this apply even if it is not venting straight up but with this slight curve in my direction? It seems almost in line with my second story windows, and I am not sure if I have any vents on that side of the house. Thank you for all this information it had been helpful!
Tom, appreciate the info. I had a mitigation system installed and got the radon down to about 3.0. I wanted it better so I sealed where the basement floor met the wall and another 2 square foot opening in the basement floor under a bathtub. After that the radon readings went below 1.0…stressing the importance of good basement sealing. I think the fan was pulling a lot of air from inside the house rather than from under the slab. An interesting side effect was that after sealing I heard a strange “glugging” noise coming from an outside drain that was connected to the basement perimeter trench (french drain). The noise stopped when I turned off the radon fan. I’m assuming that the sealing created a better suction under the slab and resulted in pulling air back through the drain trap which made the noise.
There is a passive radon system built into the sump pump basket in a drain tiled house. The vent pipe terminates on a lower roof level on the back of the house. There is no fan and the radon test came in at .9, way under the 4 maximum. However the discharge pipe is within 10 ft. of a window. As per buyer’s inspector, they want the pipe extended to go above the roof line. We are wondering why they are asking for anything with radon levels that low.
Radon vent pipes through the roof are supposed to follow the plumbing code, which requires 10 horizontal distance from any window or opening into the home, unless the vent is 2 feet above the opening. I agree with you it is kind of ridiculous as there is no real issue, the plumbing code is to prevent sewer gas from getting into the house. There is probably little if anything coming out of that ventilation pipe. If it is not too difficult it might be easiest to just extend the pipe, just let them know it may look quite ridiculous and if it is too high it might require some guy wires for support. Alternatively you could tell they you will just cap it. Then they might want to retest the radon and see if it is any higher without the passive vent.
Yes, I’m sure your are correct in your assumption. Opening in basement floors below shower and tub drains can be a major loss of pressure and need to be addressed if possible. The perimeter floor to wall joint usually does not make a big difference in most homes but sometimes can lead to almost total loss of pressure and must be sealed.
It depends on several things, if the building is build radon resistant a single suction point will likely handle the job. It needs to be a continuous slab. If the foundation footprint is divided by footers, each section would need to be mitigated individually, they could be tied together to one large fan most likely. It also depends on how high the radon is, have you done any site testing of soil samples?
Hi Ali, I would not be concerned at all. Radon disperses very quickly, usually within a couple of feet. I have tested houses where the radon vents out about 3 feet directly under a window and no radon at all was getting into the window when it was fully open for days on end.
I have a full basement of 1850 sq. ft with perimeter footing. There is a sump pump pit at each end of the basement. Do I have to seal the pump pits for the radon system to work properly? There is black perforated flexible pipe around the entire footing perimeter that terminates in the pump sumps.
Also, Tjernlund is offering a radon system that terminates through the rim joist. It mixes outdoor fresh air with the radon exhaust. Any thoughts and or experience with this product. Thanks, Tom
Tom. Can two radon mitigating systems be combined into one exhaust pipe riser? I’m planning to install a water mitigation system and while I’m at it, i’ll install a crawl space air system, using an auto damper on the water radon mitigation system that opens when the vent motor goes on.
Yes that would usually not be a problem. I’m not sure of all the details of your system plan but you may want to consider using 4 inch vent pipe and not 3 inch for less airflow resistance and better efficiency with the two fans sharing the exhaust vent.
Yes most likely the sumps will need to be sealed nearly air tight. I have installed several of the Radon Vacs by Tjernlund and my clients have been pleased. some states do not allow this type of installation however, check with local code enforcement.
I am installing an active sub-slab depressurization system in a 12,000 square foot house with a 6,000 square foot slab in the walk-out basement. I can put the suction point in the slab, or in the foundation just below the slab above the footing. Any thoughts on which placement would be better?
The size of the slab may require multiple penetrations in different areas. Any thoughts on how many penetrations can be effectively exhausted with a 490 cfm fan?
These questions are off topic but I will give you a short answer. I’ve had better success with suction point in slab, since I can usually make a better suction pit verses going through the foundation wall which is usually block and a more difficult job, and not able to work as well excavating soil through the foundation wall. Number of suction points and fan size will be greatly determined by what is under the slab, clean dry gravel being the best and wet hard packed soil or rock being the worst. Your first step in determining suction points would be to conduct some diagnostic test holes to see what type of communication you are getting across the slab. You may want to educate yourself on radon mitigation procedures so you get it right the first time. For that large of a slab you will not want to use any pipe smaller than 4 inch and if you can use 6 inch that would be the best.
Can a Radon system vent stack in a roof have any distance And height requirements from any other vent stacks, including the pair of PVC air combustion Intake and Exhaust vents of a modern furnace system?
Looks like this is still fairly active.
Is there an equation to use for length of pipe and 90/45 degree fittings?
I’m wanting to put the fan in the mechanical room in our basement, though that would require to run it to the back of the house (8′ up the wall, then 25′ to get to the back of the house, then up 20′ or so, to the rain gutter).
I did something similar with a dryer vent and needed a booster fan, so didn’t know if that would be the case with the radon also.
Hello. I live in Illinois, my radon level is 11. Unfortunately the mitigator ran into water pretty quickly in # different areas of my basement during the hole drilling test. He said he couldn’t help me. I’d there anything that can be done? Wall vent/ fan?
Radon can often be mitigated even if water comes up in the drilled hole as long as it is below the concrete even a little bit. Best solution may be to install a drainage sump with a sump pump to lower the water level below the basement floor, then a standard radon system should work well.
You need to make sure you install a strong enough fan to get the job done. There are about 100 different fan choices designed for different needs of the given system components – diameter and length of pipe and number and type of fittings and also the permeability of the subsoil beneath the slab. The goal is usually to achieve somewhere from about 50 to 200 cubic feet of air flow per minute and then you have a good chance of sufficiently reducing the radon gas. If the fan does not get the job done, put in a bigger, more powerful fan.
Depends on local code, this varies from state to state and country to country. In Canada it does not matter.
Hello Tom! We live in Illinois and our house was constructed in 2000. In finishing our basement, we sealed all cracks and used a membrane on the floor to install the flooring. The walls are poured concrete and were also sealed with a heavy product before studding out the finished wall. Our house drain tile runs entirely around the structure and terminates to an interior sump pump. I’m guessing the first thing we must do is seal the sump pump pit? Our neighbors have just installed a radon mitigation system where the vent runs up past the roof. That has alarmed us and we are considering installing a radon mitigation system (although we have not received test results yet). We would like to use a horizontal system if possible as we have a roofed porch wrapped around the entire first level of a two story house and the vent stack would look awful. If we could install the horizontal system, it could run horizontally out of the basement under a deck/porch area. The vent would run under the decking for 10 feet, terminating 6 feet above ground and exhaust outside the existing structure. Thank you
My neighbor just installed a radon mitigation system . His vent terminates above his roofline about 10 feet off the ground. My property is located approximately 35 ft from the vent and I am concerned that the radon gas might be blowing towards me when I am out in my yard Should I be concerned ?
My neighbor recently installed a Radon Mitigation System . The vent pipe is on the end of his house closest to my property which is approximately 25 feet
Should I be concerned about breathing the Radon exhaust when I am out cutting that part of my fairly large lawn
No worries. Radon gas dissipates very quickly once in the outside air, typically in just a few feet away from the discharge there will be no measurable increase in the radon level. In Canada they allow radon discharge points as close as 30 CM from an open window which is less than one foot.
As I just stated to Rob, No worries at all. Radon gas dissipates very quickly once in the outside air, typically in just a few feet away from the discharge there will be no measurable increase in the radon level. In Canada they allow radon discharge points as close as 30 CM from an open window which is less than one foot. I have confirmed this several times with my own testing.
If you live in Canada that would be what is recommended. Most of the US is behind Canada and stuck on the old EPA standards that basically follow the plumbing vent code that was designed for sewer gas which can be quite stinky at times, which is the reason it is required by code to vent above the roof. If your state allows it venting horizontally has several advantages over an above the roof vent location.
Hi Tom, I had a radon system installed in my home. it is located in the basement of our home and there was also a previous ventilation system in the basement that isn’t working anymore. My concern is the clearance of the old ventilation and the radon system…they are less then a foot away from each other and at times I get an unexplained pressure buildup in the home could this be that they are two close to one another causing the unexplained pressure buildup?
“Good quality low restriction caps cost about $20 to $35 and most people don’t want to pay it. I offer screened rain caps as an option. In my opining the best reason for a cap is to keep critters out of the pipe for low air flow situations or in case the power gets turned off. I have taken quite a few dead birds and squirrels out of radon fan housings. So I usually just install a stainless steel screened cap, that is open to the rain.”
Could you possibly direct me to a website link for this item so I can see what it looks like, and/or possibly order one for myself?
Here is a link to Amazon for a 3 inch PVC Termination Vent with Stainless Steel Screen: https://www.amazon.com/Raven-Termination-Stainless-Slotted-Condensation/dp/B01BW2VWG0/ref=sr_1_2?dchild=1&keywords=stainless+steel+screen+radon+vent+cap&qid=1605741249&sr=8-2
Not sure Diane, that could be possible I suppose, but hard to say without looking at it. Best to have you heating company take a look to evaluate.