Radon mitigation in the home

[Dani]

Hello,

As a public service announcement, test your home for radon. Radon enters through the ground and is radioactive and high levels of radon are the leading cause of non-smoking lung cancer. Unfortunately, not many people know they need to get their home tested. (We didn't!) We recently found that we had high levels of radon and are now needing to purchase a radon mitigation system for about $10K. Without a mitigation system, you can lower radon levels by opening windows and circulating fresh air through the house.

[rproffitt]

The system we installed was about 1K USD in 2000. 200 bucks in pipe, fan unit, wire and conduit. 800 bucks for labor. Near Boston, MA these units were in most homes and came to be because as we made the homes more airtight, unwanted gases would build up.

The other mitigation system is the air exchange system in the HVAC system. At 10K I'd get 3 more estimates. Something's wonky here.

Inflation much?

[Dani]

Inflation much?

It’s Silicon Valley with Silicon Valley prices. All construction work pricing here is absolutely bananas. The only reasonably priced guy we found has been our painter who drives 3 hours each way (where housing is a lot cheaper) to do work for us.

We bought our house with a crawl space with a dirt floor. 2 months ago, we did an encapsulation project where we enclosed the crawl space so we could use it for storage. After that project completed I did some research and discovered we had a radon problem. I had never heard of radon before and it wasn’t something that was done during the home inspection. Unfortunately we now need to retrofit our $50,000 crawl space encapsulation (that was a different company) because no one told us that gases coming up from the ground were a thing.

[Dani]

My husband is wanting to integrate an air exchange system into our HVAC because we had one in our townhouse rental in Menlo Park and he really liked it.

Our current home came with a fan that blows air up into the attic where it escapes, so we crack a window open on the opposite side of the house and the negative pressure pulls the air in and through the house and up out the fan. My husband doesn’t like it because the air intake is just an open window and doesn’t go through a MERV filter. His goal is to have a way to keep the CO2 levels inside down when the air quality is poor outside (eg if there’s a forest fire and we need to keep all windows closed for many days).

Oh, what a different world this is than NY! I can’t remember ever cracking a window open in my NY home all winter long during childhood.

[rproffitt]

Just checking HD. See https://www.homedepot.com/pep/VEVOR-4-4-5-in-Radon-Fan-Installation-Kit-Quiet-190-CFM-Radon-Mitigation-Fan-System-Kit-with-2-Couplers-Pressure-Indicator-DFSTJ4INCH19VK5CKV1/333815085 which is the basic kit and fan. The piping is basic plastic piping. I've seen PVC, ABS sewer pipe (cheap!) and then some mounting of same.

10K is highway robbery. There might be some permits to be pulled but I wouldn't know about that as I'm an avid DIY person with long years of work in electronics design, motor control, high voltage work up to 480V (yikes) as well as basic skills in home construction and millwork in metal, plastics and wood.

Was the persons quoting this work on the list at https://www.cdph.ca.gov/Programs/CEH/DRSEM/Pages/EMB/Radon/Certified-Radon-Services-Providers.aspx ?

PS. This is not rocket science. While certs are great, any decent HVAC company should be able to do this.

[Dani]

My understanding from the consultation is that they need to cut slots throughout our vapor barrier and snake piping underneath all of it. Then, each of the blocks of rigid insulation around the walls needs to be cut down in order to add vapor barrier up the walls and tape it to the concrete. Then piping up and through one of the vents and up the side of the house. I think the vast majority of the cost is in the labor. They said it will be about a week’s worth of work.

[rproffitt]

In MA the vent goes out and done. My best advice is to get 3 bids.

And for this much, they better be on the list at link provided.

This is not rocket science. Just HVAC work. Not even close to what you do for asbestos mitigation.

[Dani]

In MA the vent goes out and done.

In CA, the vent is required to go up the side of the house and the exhaust must be above the roof line.

But that isn’t where the cost is. It’s in the labor to retrofit the existing encapsulation.

[rproffitt]

And you have more than one quote.

O
My old house just got a new foundation for 8500 but I've heard of price ten times that. I love my property manager. Yup.

[Dani]

And you have more than one quote.

Not yet. So far I tested for radon with two different digital monitors and had a consultation with one company. Waiting for them to send a formal quote while I look for another company to get a quote from.

We got 3 quotes for encapsulation and it ended up being a $50k project for us.

[Dani]

My old house just got a new foundation for 8500 but I've heard of price ten times that. I love my property manager. Yup.

Are you sure that the company hired did a high-quality job? It sounds like your property manager is incentivized to always hire the lowest bid.

[rproffitt]

To be clear, the company that did the foundation work does that all the time. In this city so many homes have/had river rock and mortar foundations. While this home has stood for over 80 years, the mortar has degraded to where you can break it up with your hand.

This item has been on my list for decades. Glad it's done and yes, it's good work.

The last items are a covered parking pad with EVSE which means a new main panel. That would be worth a lot to renters now and future but what I can write off is limited to repairs for now. I know I can write off the electrical work but the parking pad and EVSE would not be allowed today.

[Dani]

Was the persons quoting this work on the list at https://www.cdph.ca.gov/Programs/CEH/DRSEM/Pages/EMB/Radon/Certified-Radon-Services-Providers.aspx ?

While certs are great, any decent HVAC company should be able to do this.

Yes, they are listed there, as well as being listed with the NRPP. At your suggestion, I did a bunch of research today, and can't find any local HVAC company that claims they have experience with radon mitigation. Perhaps I should add that, in addition to radon mitigation, my husband is eager to install an HRV or ERV. Most likely that will be with an HVAC company.

[rproffitt]

In my opinion 10K is about 10 times what these cost years ago. Example: https://www.reddit.com/r/homeowners/comments/1b46zrb/radon_tested_27_single_level_home_should_we_still/

Next is the discussion about how much or what reading you are seeing. There is no zero here. Radon is present almost everywhere. I didn't ask what is the exact reading.

[Reverend Jim]

The city is making free radon testing kits available starting today so with all this talk I think I'll go pick one up this morning.

[avabennett]

Thanks for bringing this up — radon is definitely one of those things a lot of homeowners don’t think about until they see test results. If you haven’t already, getting a professional test done is the best first step, because DIY kits are okay but can vary in accuracy. When levels are high, installing a mitigation system (like a sub-slab depressurization fan) can make a huge difference and is usually not as expensive as people worry. It’s also worth sealing obvious cracks and openings in the foundation first — that won’t fix everything, but it helps. A qualified radon contractor can walk you through your specific situation and options. Just being aware and proactive can really improve indoor air quality.

[Dani]

It's been a few months, and we've actually had this taken care of already. The radon levels in our home went down from 7 pCi/L to 0.3 pCI/L. (We test with both EcoQube and Airthings monitors.)

[Reverend Jim]

I just got a test kit yesterday so I'll know in a few days what an average reading is. My kit measures in Bq.

[Reverend Jim]

My younger son, four houses down, got the same radon test kit that I did. You can get them for three weeks from the library. His house was built in 1981 and ours in 1985. The meters have two displays. The bottom is the spot reading and the top is the average. Our meter, after the calibration was done, started at 391/390 (Bq) and after ten days settled down to 293/252. His settled down to 57/54, which was very close to where it started. I expected ours to be higher because our house is EEE (2x6 well sealed) and his is not EEE (2x4). Still, I was surprised at how big the difference was. Yesterday he brought over his kit and we put it right beside ours. The spot readings this morning were 293 for ours and 57 for his.

So we are in the classic "a man with two watches" scenario. Either one of the kits is bad or they both are.

I contacted the manufacturer and (of course) got their AI assistent (human feedback within 24 hours). The AI "said" that even side by side, spot readings could fluctuate like this. If that were the case I'd expect both units to fluctuate, but only one is.

[Dani]

I would recommend the testers that I used. They were recommended by our radon company and both testers show similar results.

[Reverend Jim]

I did a reset on both and left them side by side. They are still in calibration mode.

[Dani]

The testers I use do not need to be calibrated. Just put them in the room, turn them on, and one begins giving you a rolling average after the first hour, while the other takes 24 hours before giving you a rolling day average.

[Reverend Jim]

After a day and half with the two meters placed 2 inches apart, one reads 240 Bq and the other 343.