Hi Ryan,

Being in Minnesota, we never do an outside system if we have an interior route, but we have probably 800 to 1,000 exterior systems in operation. My guess is that 50% of the systems in homes without drain tile (meaning: low air velocity) freeze up after a couple days of below zero temps.

I've pulled a few frozen systems apart, and the pipe is packed tight with snow-like ice crystals. If we've had problems with falling ice inside the pipes, I'm not aware of it.

I've been told that a fan that is not moving air is not working, and not working- it's really happy and will live a long time. The small amount of heat from the running fan eventually melts the ice crystals. We tell our clients to leave the fan on and call us it the gauge doesn't go back to normal after a few days of temps in the teens. We rarely hear back from them.

In exterior systems with low air velocity, we'll pull tubes of 1/2 inch pipe insulation (normally used on the outside of pipes) through the inside of the pipe. I'm sure it helps, but they still freeze up.

Our interior systems rarely freeze up, but we insulate horizontal pipe runs and the pipe above the fan.

A good home builder will prevent springy floors by using joist spans well below code. His wall studs will never be 24” on center. His water supply will be copper, his siding cedar or cement and his basement fill will be clean crushed rock- even though cheaper alternatives meet code. The low and average quality builders meet code. He exceeds code and his reputation allows him to charge a premium price and thrive. This same environment exists in the radon industry.

Where should the ‘code’ be in radon? As in home building, it should be the minimum required to provide a safe product for the consumer. Not a good product, but a safe product (think: Masonite siding). The ANSI AARST standards have left behind the idea of the minimum requirement for a safe product and are racing toward the minimum requirement for an outstanding product. I predict that if this doesn’t change, the end result will be states and municipalities rejecting the recent ANSI AARST standards. We did quite well under the EPA protocols. I’d vote to return to them. I could also live with ASTM E-2121-3 (with a minor revision).

Steven,
Mechanical codes may have changed regarding hanger spacing for plumbing pipes designed to carry heavy slugs of water (think: multiple simultaneous toilet flushes). But Charlotte Pipe recommends 4' spacing only when ambient temperatures are above 120 degrees. https://www.charlottepipe.com/Documents/PL_Tech_Man/Horizontal_and_Vertical_Support.pdf

The Kentucky bill was my favorite- before yours!

Medical experts will say that when it comes to prescriptions and supplements, take the smallest dose that will get the job done. In the same way, when government intervenes in the free market, it should apply the smallest dose of intervention that gets the job done. With licensing of radon contractors, that means: a law that gives the government the tools to regulate unqualified and untrained contractors, but nothing more.

Kudos to all who collaborated on the Colorado law. In my humble and biased opinion, you've come pretty close to writing the ideal licensing law- one that should be used as a model for all who want a license law.

Some winters we have no calls regarding freeze ups. It usually takes a few days of -20F. Our current cold spell has been unusually long (2 weeks) but not severe (average temps -6F to 6F).

I’ve taken 33 freeze up calls over the last week or so. After confirming they have an outside system, they get the standard talk: “Water vapor and droplets freeze… it will open up in 1 – 3 weeks…the fan is not moving air, which means it’s not doing any work which means it’s really happy and will run forever like this…don’t worry… the danger of radon is long term exposure... In fact, if you called Health Canada and said ‘My three day radon test is 8, what should I do!?’ you’d be told ‘Re-test for 3 – 12 months and then call us’”. The standard client response is “OK”.

This raises a couple questions:
1. Would the clients above have said ‘OK’ if there was an alarm sounding?
2. Is it in our client’s best interest to sell them an expensive solution (heat tape) to a short term self-correcting problem that is not a health risk?
3. Our wise and prudent neighbors to the north tell their citizens “Health Canada recommends long-term radon testing to determine if the radon concentration exceeds the Health Canada Guideline level of 200 Bq/m3. A test duration of at least 3 months is recommended, and 12 months is optimum.” In other words: The risk of radon is long term exposure. Put a decision to mitigate on hold for 12 months! Elevated radon does not require an immediate response!!! WHY ARE WE EVEN DISCUSSING INSTANT FAN FAILURE ALARMS!!! (Sorry for shouting. This gets me a little agitated.)

It took us a couple months too to figure out an old farmhouse. It had city sewer, so we didn't worry about the floor drains- just made sure they had water in the traps. Then we found an old floor drain that apparently went out to a dry well. A wad of paper and a blob of concrete and we were done. We had the same problem with a cistern drain on an old house.

I'd heard about the electric conduit house. As I recall, 100's of pCi/L were flowing in through the conduit. It's on my "Problem House Checklist". I hope every mitigator who doesn't have such a checklist is building one, and including all the suggestions in this string.

As a young builder, Dad taught me to go to conventions and listen quietly as others shared their secrets. I'm going to go against his advice and share my checklist. We generally bring it out after we have communication across the entire slab, including suction at adjacent slabs, where need is indicated. See attached. Feel free to point out what it is missing.

Quick update:

The radios were removed from the room with the slate tile and put in the garage. A Corentium under a stainless steel salad bowl taped to the slate floor (covering the corners of 4 tiles) and another on a table both read about 8 pCi/L. The radios and slate are not the problem.

The well water tested at 400 pCi/L, meaning it is contributing about .04 to the room air.

We did suction at the adjacent garage slab.

Radon is still about 8. More to come. And thank you for all the suggestions!

Bravo Kevin!

The better job we do at promoting this, the more effective our mitigation systems will be. An example of the problem: In a previous life, I built a home for Joe. It had technique 3 drain tile with no capillary break- the slab was poured tight to the concrete block foundation. He had water on the basement floor, and wanted me to replace the 'defective' drain tile. I told him that the drain tile was fine, but water was wicking up the face of the concrete blocks, and then running down and wetting the floor. He didn't believe me. We agreed on an experiment. I punched a 2" hole in the bottom of one of the blocks, inserted a garden hose and turned it on full force. After about 30 minutes, the rock bed was saturated and water began trickling into the sump. If I'd built the home with Ice & Water Shield starting at the top of the weep tubes and extending 24" up the wall- the floor would have been forever dry. (I've often said that by the time a builder knows how to do everything right, he's dead or retired.)

After market drain tile contractors give life time guarantees installing drain tile the way Dad taught them. My suggestions to them to use technique 3 with Ice & Water Shield on the wall have gone over like a turd in a punch bowl. I hope you, and others can be more effective than me!

I was taught years ago to tell my clients to check their manometer quarterly- when they changed their furnace filter. The current ANSI / AARST standard says we shall advise them to check it monthly. I'm being a little facetious, but should the standard be changed, advising them to check it three times a day?

In a more serious vein, I could support a $10 to $15 battery operated red light / green light silent 'alarm' with an expected life greater than the expected life of the fan. Or, a fan that gave an hourly 'chirp' when it quit spinning.

I wonder how many clients will call and say "Randy, the manometer shows that the fan you told me might last 20 years or more is still running, but please send your crew by- I'd like to pay you $350 to replace the active alarm for the third time".

Dean,

30 years ago I said that it wouldn’t break my heart to never do another one of them, but we still do 2 or 3 a month. Most are a breeze, some are a major pain. To understand what you’re dealing with, go to https://fixradon.com/resources/library-and-links/ and scroll down to “Basement waterproofing”. You’ll see how Minnesota aftermarket drain tile is done- with a 2 inch layer of rock on the footing and the re-poured slab only 1-1/2 inches thick. Our homes with aftermarket drain tile almost always have block foundations, not poured.

The 2 inch 'air gap' between the slab and the footing is the major problem. Air is freely pulled from hollow cavities of the blocks through this gap. The gap between the slab and the wall is the lesser problem. We only seal them as a last resort and the improvement in sub slab communication is usually minimal.

With normal drain tile, we’ll cut a football size hole in the top of the drain tile at the suction point. With aftermarket drain tile, we’ll use a hole saw to make a tight fitting hole in the drain tile, cut the end of our suction pipe to the radius of the drain tile and then insert the suction pipe ½ inch into the drain tile for a tight fit. If the sump is where we want the suction, we’ll go through the floor next to the sump, turn 90 and enter the sump through the side wall through the proper sized hole saw hole. My theory is that we lose less vacuum through the air gaps with an “airtight” connection to the drain tile system.

95% of the time, one suction with a RP145 does the job. If not, we start doing communication testing. Avoid the temptation to just put on a bigger fan- you’ll exhaust a lot of house air, and could cause back-drafting.

We’ve found that unless we’re creating some vacuum in the drain tile, it usually doesn’t work.

Sometimes you’ll need more suction points on the drain tile. If your suction is tight to the drain tile, the end of the suction pipe is inches from the bottom of the drain tile. This creates turbulence and you lose a lot of air flow requiring more suction points.

Sometimes you’ll abandon the drain tile suction points and do suction away from the drain tile.

Sometimes you’ll do suction away from the drain tile with dampened suction points in the drain tile.

Sometimes you’ll wish you never took on the job.

Great advice- Thanks guys.

QUESTION: I can get a Corentium Home tomorrow, or a Radon Eye mid week. Will the Corentium Home do the same job on the flux test as the Radon Eye?

BIG FANS I agree that a big fan should be the last resort. We tried suction at 6 points in the small furnace room before doing a 2nd suction point at the best one. When the retest showed no change in the radon level, we returned with the Rn4. Any additional suction points in the slab will have to be in finished rooms- probably a 2nd system in a finished room.

GARAGE SLAB I was planning to (and probably will) do suction at the garage, but am hesitating because the basement adjacent to the garage has 7.4 pCi/L, while bedroom 1 is away from the garage and has 8.9.

WELL WATER Although I've never known Minnesota well water to be a problem and the basement bath is unused and we had 2.3 pCi/L 17 years ago, I will test the well water.

MICROMONOMETER My guys prefer smoke to the micromonometer and are pretty good at using smoke to estimate Pa, but we used both here. With 2 suction points and the Rn4, we had communication across the entire slab, with -1 to -2 Pa at 8 test holes and -.4 at one.

ODD STUFF The crew did spend several hours working through our check list looking for things like an opening at the tub trap and rusted out furnace floor over open dirt, and found nothing that appeared meaningful.

Thanks again, and if you think of anything else...

Thank you David. It speaks volumes that a man who makes money selling alarms feels that an alarm mandate is a bad idea. And what the h***!!! This is only being enforced in Minnesota??? That also speaks volumes.

I have three remaining questions:

1. Our default system has the pipe in the garage. If the basement is likely to be finished, the gauge goes in the garage. In the winter, an alarm at the gauge location will be subject to long term extreme cold. In the summer (90 degrees, 90% RH), the pipe and alarm will be wet with condensation. Will the currently available alarms survive in this environment?

2. If not, will survivable alarms be invented- and will they be at a price point acceptable to our clients?

3. There are mitigators who would call the alarm issue their “Ruby Ridge”. They won’t comply, and will suffer as a result. Does the standards committee really want to play the role of the feds and force this confrontation, or is it time to stand down?

This interesting conversation has focused on the pros and cons of techniques for announcing fan failure and system failure without fan failure. I look forward to hearing more, and identifying new “best practices”.

But the issue at hand of ANSI / AARST standards requires answering a prerequisite question: how are “should”, “shall” and “best practice” to be used in the standards.

Our standards should use “shall” to identify minimum acceptable practices regarding things like pipe slope, manometers and labels. As entrepreneurs in a free market, many of us will exceed the minimum and brand ourselves as “better than the other guys”.

But the all-important “shall” can become an Orwellian bludgeon when a governing agency interferes with the market and demands the sale and purchase of a product that neither producers nor consumers want. I think “shall” does belong in the rules regarding producers installing seat belts in cars and smoke detectors in new homes. Does it belong in the rules regarding system alarms? I vote an emphatic “”NO”. Identify alarms as a “should” or a “best practice”.

You're right Rob. But when it's been below zero for a while and your phone is backed up with clients waiting to tell you "my gauge is at zero", all you can do is tell them to call back if it's still at zero in 3 or 4 weeks. A service call won't fix a freeze up- it takes warm weather.
And what about normal fan failures. You'll tell the client to push the "hush" button on the alarm. But can all of us get the fan replaced before it goes off again? How many times can you tell them to push the "hush" button before they move to a motel? Once? Twice?
30 years ago, I was taught "Advise the homeowners to check the gauge when when they change their furnace filter- they'll establish a habit- and a couple month's of radon exposure has minimal risk". So maybe we need an alarm that sounds when the fan has been off for 3 months. I'm being facetious. Alarms are a silly misuse of other people's money. They may benefit some businesses, but given the option, how many clients would pay for one?

Wally,
We rarely see a froze-up interior pipe. And when they do freeze, it's easy to add insulation. But after a couple days of -10, I do get calls from guys asking if they should go up on the garage roof and remove the 3' inverted icicle on top of the radon pipe.

Hi Dallas,

Maybe there’s some confusion on my part. I was told that around Oct 28, the standards committee discussed changing the alarm standard, and the Minnesota Dept. of Health vigorously endorsed the alarm requirement. A vote was held and the alarm standard was left intact. Shortly after that, our group began exploring legal and legislative options, and the email above was drafted.

I’m sincerely grateful for the advice and recent guidance you’ve given on this- the Oct 28 meeting was not the end of the line, there is hope. I hope you can appreciate the tension. Contractors have told me that they would defy the government or leave the business before they would subject their clients to a system alarm.

Randy Weestrand

What I've learned so far...
"Air watts" is an ASTM formula [(cfm x vac) / 8.5]. Units with the same air watts are supposed to perform equally. But I have to believe that the unit with the highest vacuum will move rocks and wet clay lumps through the hose most effectively.
"Two stage motors" have two impellers that create higher suction at the expense of CFM. They run at lower RPM, are quieter and are more expensive.
A 2-1/2" hose might really be a 1-1/4" hose with 2-1/2" ends.
The Ridgid 50358 and 50373 both have 100" and 105 CFM. The 50373 has a very interesting dual filter system that senses filter back pressure and 'back-washes' the filters as needed to keep them from loading up. A reviewer said he vacuumed up a full load (10 gallons?) of drywall dust without cleaning the filter and no loss of vacuum.
The Ridgid tech guy said the 50338 would be the best radon vac. It has 193 CFM (wow) but only 56" of vacuum. I think I disagree.
Rob- The Nilfisk guy told me that most of their units have small hoses. They have one that's not really portable with a 2" hose for about $4,000. But- they will come to your job site to service it.