Hi all. We usually keep the basement windows open just to get some fresh air because we work out maybe 3 to 4 hours weekly. Have a walk out basement. it was so humid, turned on the dehumidifier and shut the windows. Levels are much higher in the last two days since I did that.
Even with the windows closed in the winter, it wasn't as high. I have a Boiler in the basement, not sure if that affects it or not.
I live in a part of the USA where radon isn't supposed to be a big deal (Plano Texas). Ground floor apartment in a multi-unit apartment building. The building is about 25 years old.
I purchased 3 online radon detectors. All were initially placed 5 inches from the floor (I have now learned that this is too low).
The readings after the first 12 hours are as follows:
Online, I've read that the first 12-hour reading isn't always accurate. Indeed, somesay wait 48 hours! Nonetheless, I'm starting to think there is a real problem here.
What has your experience been with readings after 24 hours? This is all quite surprising: I was naively expecting that the readings would be very low, given all I've read about how radon isn't common in Plano due to the kinds of rocks in the area!
Hi everyone, I’m posting here about a problem I’m experiencing with my radon monitor, and I’d like to know from you how likely it is that this is an instrument error rather than a real event.
Device: Forensics Detectors continuous radon monitor (semiconductor alpha sensor, 6-hour reading blocks), running continuously for about 3-4 weeks.
House: old stone house (1950s or older) in a small hilltop village in southern Italy. Geology is sedimentary flysch — not volcanic, not granitic, low uranium content. 80 cm thick stone/brick walls, ventilated crawl space under the ground floor, 3 floors. It’s a vacation home, empty most of the year. Important detail: the house is very humid (documented rising damp in one wall) and was fully closed during the event.
Baseline data (verified over 3 weeks):
• 14-day average with the house closed: 55-57 Bq/m³ (about 1.5 pCi/L)
• Daily averages while closed: 52-70 Bq/m³ (1.4-1.9 pCi/L)
• Historical maximum peaks while closed: 117-140 Bq/m³ (3.2-3.8 pCi/L)
• With windows open: 12-39 Bq/m³ (0.3-1.1 pCi/L)
The anomaly — house EMPTY and fully closed, nobody entered for days. Five consecutive 6-hour readings, then an instant return to baseline: • Jun 30, 15:59 → 5,154 Bq/m³ (139 pCi/L) • Jun 30, 21:59 → 14,203 Bq/m³ (384 pCi/L) • Jul 1, 03:59 → 4,870 Bq/m³ (132 pCi/L) • Jul 1, 09:59 → 4,859 Bq/m³ (131 pCi/L) • Jul 1, 15:59 → 3,578 Bq/m³ (97 pCi/L) • Jul 1, 21:59 → 47 Bq/m³ (1.3 pCi/L) ← back to baseline
The Accumulated Peak stored by the device is 19.1 kBq/m³ = 19,100 Bq/m³ (516 pCi/L). Total duration about 25 hours: sharp rise, plateau, sharp fall. The Total Count jumped from ~109 to 2,964, so the chamber physically registered roughly 2,600 pulses during the event — internally consistent with the displayed concentrations, so it doesn’t look like a pure display/software glitch. The cumulative session average is now “poisoned” at 430-530 Bq/m³ even though 83 of the 88 readings average about 60 Bq/m³.
My questions:
1. Has anyone seen this exact failure mode (multi-hour spike to thousands, spontaneous recovery) on Forensics Detectors or similar semiconductor-based consumer monitors?
2. Does the Total Count behavior (real pulses counted) fit the humidity/condensation failure hypothesis?
3. Is there any plausible physical mechanism for a REAL 25-hour radon excursion of this magnitude in sedimentary geology? No earthquake reported; I’m checking weather archives.
4. Planned next steps: outdoor test of the unit, session reset, and a 3-month CR-39 passive dosimeter as an independent referee. Anything else you’d do?
For what it’s worth, I was NOT in the house during the event (zero personal exposure), so this is about understanding the instrument and the house, not panic. Thanks!
Are these levels fine or should we retest in the winter? Just got an inspection on a house built 1982
I live in a new build that was finished last year. As is typical, some cracks are appearing in my foundation, but I’m not too concerned about the size of the cracks and structural integrity. The width of the cracks ranges between 1/16 and slightly under 1/8 inches wide. I am, however, worried about radon leaking through these cracks and avoiding the Radon Reduction System. I’ve included pictures of the cracks on the wall and on the floor as well as an image of part of the radon system. Are these cracks an issue and do you think I should seal them to avoid radon leaking into the basement?
Got an Airthings Corentium and started the test. I want to see the results short and long term. Any advice would be appreciated.
This cant be accurate! Really hoping this is a dud or something. I reset the device after it initially read 40 and it went up to 105 and then today it says 103
As I read through various posts about high levels of radon frankly the numbers confuse me. The reading on my airthings in the basement has increased slightly as summer approached. Now it’s at 95 on long term average and fluctuates on the daily average between 80 and 110. Can someone explain to me what that means and if that necessitates mitigation? Much appreciated!
My home office is in the basement of my house and I work from home, been seeing things about radon more frequently so I picked up this scanner first 24 hours my readings were around 8 then jumped to 10. Called a guy to come out and talk about a mitigation system the very next day which is now scheduled for install on Monday. The scanner has been running non stop since and my numbers seem to have dropped pretty dramatically over the past week. Nothing has really changed except I painted my office basement flooring and closed my windows and doors over the past few days because of the crazy heat.
Did I panic and jump the gun? Is a system even needed?
I live in Hamilton and am interested to know if anyone lives here or near and has hired a radon mitigation company/person to install one and what the results were.
Hi all,
We have recently discovered that we have fluctuating radon concentrations that can go up to 400 Bq/m3 during the winter in our century-old house, and I'm currently planning our radon mitigation measures.
I'm pretty handy and am DIYing the mitigation systems. Since we have an old house with various complex features (concrete-capped stone foundation, portion in crawlspace, mix exposed soil/concrete basement floors), I want to go step by step in adding mitigation systems + testing between the installs to avoid overdoing things. I'm currently going in with the first install: a radon fan + exhaust over the sump pump hole.
I'm currently planning the radon exhaust position on the side of the house and am facing an issue finding the right spot for the final exhaust outside - see image attached. The red circle under the heat pump is the point where the pvc pipe will exit the basement. The Red line is option A (red line) for the exhaust pipe and end, and is what I had originally planned, but it seems closer to the windows than option B (yellow line), and makes for quite a longer pipe.
I know best practices involve going above the roof line but I'm more and more tempted to try out option B first and see how the radon readings go, especially as we are planning to add a deck to the left of the picture at some point. Option B seems to be the most centrally remote point from all the openings around.
The white cap on ground level to the right is the basement air-exchanger intake/exhaust (to be modified to move the intake away from the exhaust...another project!). The white cap in the middle of the wall is the kitchen exhaust
Anyhow, I wanted to have the thoughts of the community on the radon exhaust placement. If you see another option, please feel free to share! With Thanks!
On a hunch I picked up two Ecoqubes and placed them at opposite sides of my house. They’ve been going for a week now and are both averaging ~2.5 pCi/L with swings +/- 1 pCi/L. Would it be worth it for me to get a mitigation system? How much of an improvement can I expect from adding a negative pressure vent under the slab? Our house has two load bearing block walls that separate half the basement as well as the crawlspace from the rest of the house, so I’m guessing all 3 slabs will need to be vented.
I ask because the EPA says reducing levels below 2 pCi/L can be difficult. If installing a vent may only drop our averages by 0.5-1.0 pCi/L, I may just say F it. But if I can reasonably expect to get my levels under 1.0 pCi/L, I’ll probably do it.
Thoughts?
I peeked at my 20 year old radon system gauge in the crawl space. While the negative pressure balance seems okay, the upper measure is low off the scale. Does that matter; does that mean it is still working, but only working weakly?
I will do a air test next. It's been a while, but I've tested low every time. Most recent was probably a couple/few years ago.
I live in the area known for elevated radon and during home inspection it was confirmed elevated radon levels, I have several estimators lined up in next 2 weeks starting with one tomorrow morning. I just started researching this topic so I am not fully educated yet. What would you suggest to ask estimators to ensure it is good system. I just learned that membrane is usually 6mm and 10mm optional upgrade and even maybe fiber reinforced membrane, fans can be normal AC or EC variable speed and power savings with EC are real advantage what are optional upgrades vs standard basic system. I heard encapsulation for conditioned crawl space is extra. For reference it’s 2 stories house with attached garage 2800sf verbally quotes start in 2100-2300$ for standard package not counting extras. I thought it would be cool if system can be self tuned based on continuous monitoring like if radon high then fan full speed vs if it’s low radon fan slowing down but apparently it is not an option for residential systems, do I need one fan with multiple intake pipes or 2 fans etc. please share your thoughts on this topic and if any extras with doing or it’s money waisted
I have high level radon in my basement 9pci/L from last 3 years . Just found out radon and small amount mold on basement wall. so my question is do dehumidifier affect radon levels In the basement and how do I know I need to put Radon mitigation system ?
I don’t know anything about radon, but I’m curious about it after having dealt with a strange odor that appeared only in my room by the door frame that made me sick whenever I smelled it.
I keep the windows open most of the time, and suddenly after months of smelling it, it no longer appears.
So radon came across me in my search for clean air and I want to test the rooms air quality. Does this mean I would need to keep my window closed for 90+ days to get a clear read on the radon levels? Could I use air purifiers during that time? Air quality has been important to me and I can’t imagine keeping this room shut for 90+ days. It gets stuffy in there quick.
What’s your suggestion?
[effacé]
I was impressed with the man and son that did my radon mitigation. 4 quotes 3 out of 4 wanted to go out either side of my house cut through my brick and up my house. I wanted it through my canning room up my pantry up the roof. One guy said he could make it happen. He did.
Cost me 3k for here in Idaho. What stuff like this cost for you?
