Radon mitigation stack

[Ford12508]

Was just at my sisters home and they have a radon system. The stack goes up the side of the house and is just 3" thin wall pvc. At the top it just terminates, no down turn or anything to mitigate the rain. Any reason for no down turn? Obviously with the fan it's not an atmospheric system

 

[sixty4]

Mine does the same thing. I doubt what rain water would get in, would not cause any problems.

 

[Showkey]

Pretty much normal........

Vent is just suppose to be away from the doors, windows, air intakes and eve vents to free air.
Through the roof venting in cold climates can cause ice build ups.

 

[DrewFSD]

They're usually tied into the sump system so if it does rain hard enough it would just go to the pit. Plus you want to vent the radioactive gas away from people not down back at them

 

[Jeepster04]

If it had a turn down then it would blow the radon right back down where people could be. Some rain may get in there during hard storms but the radon outlet I felt had some power behind it. Probably blows most rain away.

 

[Firebrick43]

Ironically now they are saying that radon reduces cancer.

https://www.sciencedaily.com/releases/2008/03/080325122807.htm

 

[Chuckster in NJ]

The radon system stack MUST terminate above the roof line and the fan should always be running 24/7/365....... "IF" any water does gets into the pipe it will just drain into the aggregate under the slab and the fan will dry any moisture.
I have a cap with a screen to keep rain out of the pipe on my radon pipe but MOST radon systems don’t have a cap.

BTW! I was in Bad Gastein, Austria in the mid 1980’s and they transport people on a small train into a mountain for "natural radon" treatments for various health ailments...... The water that flows out of the mountain was naturally hot water.

 

[Jeepster04]

Random bit, a quick google search on this matter indicated its illegal in Ohio to have a cap on a radon vent stack....

 

[engineer2]

Through the roof venting in cold climates can cause ice build ups.

I have a cap on mine and may remove it. You do get ice build-up. The fan is essentially venting moisture-laden air. Once an ice chunk came off and slid down the roof and dented the hood on my car.

BTW, the radon fans are rebuildable despite what the manufacturer says. Moisture can get in and ruin the fan bearings. Simple to take apart and replace the bearings, and you can do a better job caulking it than the factory did.

 

[nadogail]

If you are deeply concerned about the possibility of rain entering the vent you can put a rain hat on the vent pipe like you would see on a gas water heater.

 

[3onthetree]

Side mounted stacks just need to extend 6" above the roof, straight up. Around here they use 2x3 downspouts and match the color of the siding. Any rain and condensation just flow back along the required 1/8" per ft slope to the suction point.

In some areas local overrides allow you to divert the stack up to 90d (but clearance requirements expand), and also you can have a rain cap or rodent screen.

 

[yeldogt]

Seems to be various ways this is done -- it's not an attractive addition to many homes. I'm always surprised at the number of new homes built with external systems.

For the internal systems -- they have to be set up so the fan is close to the exit so that any crack would not be a pressure point to the inside.

My place in PA is in a radon area -- The codes are more township driven as they are not required. It's more of a best practice ... and that leaves much to the installer.

The open ones typically have a drop -- it looks like a gas hook up with the dirt trap.

There are side discharge units as well that still use the 50w fan

 

[engineer2]

I'm always surprised at the number of new homes built with external systems.

Same here. I found room in the plumbing chase and installed ours internally.

We were at 4.0 picocuries/liter, which is the minimum actionable level. I didn't want any issues when we sell the house someday. I put a 3 speed ceiling fan control on the motor and change it as needed. Certain times of the year you don't need to run it full blast. 2.2 pc/l is as low as I can get it to go. Most if the time it's around 2.4.

 

[D45]

I installed a T fitting on mine

 

[tfb]

Not addressing the question but... on the radon subject, here in PA you are not required to conduct a radon sample test when selling a home. However, if a buyer requests it, and you agree, beware! If the results come back positive for radon, regardless if the buyer follows thru with the purchase, the seller has to install a under slab system.

Best advice I can give... Never agree to a test. And the best advice to a homeowner, install your clothes dryer in the basement with a outside vent and you'll never have a radon issue.

 

[yeldogt]

Not addressing the question but... on the radon subject, here in PA you are not required to conduct a radon sample test when selling a home. However, if a buyer requests it, and you agree, beware! If the results come back positive for radon, regardless if the buyer follows thru with the purchase, the seller has to install a under slab system.

Best advice I can give... Never agree to a test. And the best advice to a homeowner, install your clothes dryer in the basement with a outside vent and you'll never have a radon issue.

Is the mandatory install after test .. new? Don't remember hearing about it .....

Since I typically buy old houses needing work ... they all end up failing for radon and septic. They all have been right in the 4 range -- know that will be fixable. Same with septic ... it's only money !! It's the buried tanks that have to be investigated throughly ... bad well -- I walk. I never buy a house w/o do all the tests .. done by very good people

 

[tfb]

Once you preform the test, you're legally obligated to reveal the results on the sale disclosure form... so whether you install or not, you're paying the cost of the system in the negotiation process of a sale.

I would never agree to the test, and I don't live in an area of high radon. I don't know how accurate the labs are who do the tests. And frankly, there is no upside for the seller.

 

[toolmiser]

Not addressing the question but... on the radon subject, here in PA you are not required to conduct a radon sample test when selling a home. However, if a buyer requests it, and you agree, beware! If the results come back positive for radon, regardless if the buyer follows thru with the purchase, the seller has to install a under slab system.

Best advice I can give... Never agree to a test. And the best advice to a homeowner, install your clothes dryer in the basement with a outside vent and you'll never have a radon issue.

We just got ours tested and (The result of your test AE855889 was 9.0 pCi/L.) which they say anything over 4 is high. We do have a dryer in the basement. I've had it tested a couple times (Years before) and it was maybe half that amount. Maybe a bad test? House is 40+ years old. No changes in at least 10 years.

 

[56Mark]

I helped my son remodel a house last year that he moved into. About 4 months ago he checked the radon and it was very high, but he checked it at probably the worst time while we had a cold rainy spell. The house has a full basement with about half of it finished. He was checking on the basement level where they have a big den/play room for his kids. He bought a digital monitor and checked it for a few weeks. He was running in the teens and upper 20s when it would rain, but never went below 16. He starting sealing up everything he could. We cut a 5" hole in his slab and ran a pipe up into the attic. The next day when we went to finish the piping in the attic and out the roof, I was amazed at the amount of condensation in the pipe. We had to dry it to glue the fittings. We installed a fan in the attic and went out the roof. I don't think the amount of rain that will get in the pipe is anything compared to the condensation being removed from under the slab. The house was built around 1960 and we were lucky there was gravel under the slab and we cleaned out the gravel around the hole for about 18" away to make a big negative pressure area. It has been in now for about 2 months and his long term average is showing 2.6. It occasionally will go over 4 on the short term reading and every time it is during a rainy period. I think the water seals up the E. TN clay around the house and up through the slab is the easiest path out. FYI, radon is heavier than air. We probably had less than $400 in the system and researched it to death but are happy with the results. I think the reading may drop more if he ever removes the finished walls in the basement to seal the crack between the wall and slab.

 

[Jeepster04]

Mine was mid to upper 3's last time I checked it. Simply opening a crawl space vent dropped it below 1....

 

[GTFiero]

Many sump systems incorporate floor drains located in the basement floor. Those drains have traps. Unfortunately the continuously running Radon vent fan dries the water in those traps. This exposes your basement to more of the radon should you turn off the fan, or sump stink. Yuck!

According to a Radon expert for the state of MI, all you have to do is just slightly crack a basement window to remove the radon threat completely. Apparently radon dissipates very rapidly with the air allowed in by the cracked window. She alluded to the cracking of the window as a way to void radon testing kits. So it goes. Makeup air systems on forced air HVAC systems also mitigate the radon risk, according to her as well.

Last thought. Without a cap on the vent stack, like any other vent stack, a bird can easily fall into the stack, or somehow get in it, other critters as well. This can cause the obvious problems.