Radon

1117 Views 17 Replies 5 Participants Last post by 3onthetree, Feb 4, 2020

mpoland33

Discussion Starter · Feb 3, 2020

Not sure where to post this so you guys are the winners. I'm finishing my basement and there is a rough in down in the basement for Radon where the pipe leads down into the sump pit and it leads outside. I'm having work done on the concrete slab (long story) and they are moving that sump pit. The contrator said he'd install the radon fan if I provide it since he's moving the sump portion of the pipe. Anyone have experience in these that you could provide advice on what to buy? From what I've seen its literally just a fan that connects to the PVC

1 - 18 of 18 Posts

chandler48

· #2 · Feb 3, 2020

We installed this one: https://www.homedepot.com/p/RadonAway-RP260-Radon-Fan-23032-1/203746905 last week on a built in piping. Difference was, the piping was coming from the slab through a 6" exterior wall. We extended the pipe (4") to an elbow to exit the wall, then turned it vertical again into this fan. It is directly wired to a GFCI receptacle that is always on.

It mounts to the wall via spanners. It doesn't come with a method of preventing water intrusion, so installing some sort of screened pvc pipe loop on top would be good. I'm letting the GC figure that one out as he wanted to put a cheesy dryer vent on it.

mpoland33

Discussion Starter · #3 · Feb 3, 2020

Great, thanks for the response. Ours looks like its already directed outside but I need to figure out where it goes. For something that seems so important at home inspections, it sure is hard to find information on it

Bud9051

· #4 · Feb 3, 2020

Has the radon level been tested? The level helps determine the fan size.

If you have high levels the sump pit may need to be covered to help seal the basement floor to allow the radon system to pull a negative pressure. On new homes they sometimes install the pipes "just in case" but have not tested. If they did test and the reading was bad I would expect the fan would have been installed.

As for relocating the pipe going into the pit, that isn't where a radon system connects. There should have been a layer of gravel plus a network of pipes under the entire slab. I don't think your contractor knows how a radon system works or its proper install.

Bud

mpoland33

Discussion Starter · #5 · Feb 3, 2020

Long story short, no it has not been tested but we have 6 neighbors on our little mountain, and they all have had high levels. I'm just assuming we do and since we are having the concrete work done, he is going to install the fan.

Long story long- we recently found out the builder (in 2003- 3rd owner here) did not connect a drain tile to the sump so the sump has just been sitting doing nothing (it was connected to an exterior pipe in the basement stairwell so it runs about once a month or so it seems). So they are going to dig up the perimeter of the concrete floor and install a french drain of sorts- though they call it something else. In doing so, they are moving the sump to a corner of the basement before adding 2 more pits. When they move it, the roughed in radon pipe will be void so he has to move the pipe (really just cut it and add it to the new pit). I found out this morning that the pipe does run all the way up to the roof and runs through the attic. Should I just install the fan up there? I see online that is an option.

Because the work is being done starting a week from today, I'm trying to learn as much as possible as quick as possible so that either he can install the fan onto the PVC in the basement or I'll install it in the attic later.

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mpoland33

Discussion Starter · #6 · Feb 3, 2020

Bud, to your comment about where it connects, currently the radon PVC goes down into the sump pit but is just sitting down there in the pit. The sump lid was not sealed either which is going to be fixed with the new pit.

Bud9051

· #7 · Feb 3, 2020

U-tube manometer and it indicates the negative pressure under the slab. The drain system they are installing cannot be open to the air or the radon abatement may be defeated. Inside French drains (or whatever they are calling it) that are intended to catch water in the basement don't sound compatible. Normally the slab is sealed to the wall and all penetrations like the sump pits are sealed.

However, sump pits also provide some protection from broken water pipes or other domestic sources of water and a sealed pit won't help. Strictly my opinion, once the typical sump pits are sealed one needs to add a pit (a big bucket) open to the basement to catch such leaks and discharge them to the outside. I've seen many washing machine hoses let go, bad solder connections, and burst pipes from being frozen.

Just an fyi and I'm not a radon pro, just a builder and energy professional.

Bud

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mpoland33

Discussion Starter · #8 · Feb 3, 2020

Thanks so much for the info. He told me his system is radon compatible....but you bring up some great questions for me to ask.

With what they are doing...they are digging around the entire perimeter of the basement and putting gravel in, then a sloped PVC pipe leading to the sump pit. The PVC is then covered with gravel and then 4" of concrete is placed on top of that. After which eventually I'll finish the basement floor on top of that.

"The message I just got from the installer is:
It's radon sealed and ready in a sense that if you install a radon system, all they have to do is tap into the system without having to cut into the floor or into his system. "

mpoland33

Discussion Starter · #9 · Feb 3, 2020

oh I forgot to mention he will have to drill weep holes into the concrete walls to allow the water in to the drains that are in the basement

Photobug

· #10 · Feb 3, 2020

You should really run a test before you try to solve this. You might be solving a problem that does not exist or not going far enough to mitigate if you have it really bad. You should know what your radon level is before you start. The steps you have to take depend on the level of your problem.

I tested 16 piC/l in my home and got it down to 5 by simply opening blocked vents in the crawl space. They are still covered by snow so think if I shoveled out the area around the outside the level should drop to an acceptable range under 4.

Here is a resource I have used to help me figure it out.

https://www.indoor-air-health-advisor.com/do-it-yourself-radon-mitigation.html

3onthetree

· #11 · Feb 3, 2020

The radon access point should not originate in a sump pit. It sounds like there is no underslab piping, just a pipe stuck into the old sump lid and they called it a "system." Not quite understanding, but you are getting 3(?) new pits for water, and the old pit will remain the radon point? Is this one point centrally located or able to pull from the entire basement? At the very least, the old pit tub should be removed, filled with gravel and continue the VB and the new pipe sealed off with concrete.

If you have no underslab piping, a full perimeter loop can be installed while they have the slab cut. This can be routed to your existing vertical exit, and remain as a passive system until you have the time to test your radon level. Then, a fan can be added in the attic and more access points if needed, based on the reading.

Personally, since you are doing so much work anyway, I would have excavated a hole outside to verify if they have a footing drain, and if so, then just tied it in rather than let the water inside the entire perimeter. If I found no exterior drain tile, I would have evaluated at that point which side to dig on is the better solution.

But to answer the main question, you do not need to give him a fan to connect it to anything in the basement. You just need to make sure that you provide the best way to pull underslab air while you have a chance now.

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mpoland33

Discussion Starter · #12 · Feb 3, 2020

I must not be explaining it well enough with my lack of knowledge and terminology. When they pull the 16" trench of slab up around the perimeter of the house, he is then creating a pathway that leads to the sump. This is sealed and from there the radon PVC is sealed into the lid/sump pit. It does just rest inside of it. According to an inspector I talked to, this is a well used practice for people who do not have drain tiles or if the drain tile has collapsed...and with my contractor's system being radon certified, he said it would just tie in to the under slab work he is doing. He also said I would only need one radon fan/pipe even though I would have 3 pits. Without the fan, it would just be a passive system.

3onthetree

· #13 · Feb 3, 2020

A radon "certified" contractor would not be asking you to give him a fan. And if he is removing/relocating/adding sump pits, he would not be utilizing a sump pit as a suction entry point, when core drilling holes (not to mention he has the concrete torn up) is easier. Sounds like marketing.

There are two "systems" which should be kept separate:
1. soil water drain system
2. radon mitigation system
Best practice is to not combine them. The old easy fix was add a pipe to the sump lid. That is not recommended now.

It still sounds like when he is going to dig up the perimeter, he is not going to install a standard 4" corrugated or solid pipe, but going to install some sort of prefab channel drain, like a "waterguard," is this correct?

Then drilling holes at the bottom of the wall will allow the water from outside to enter the inside and work its way into this perimeter drain, which is carried to a sump pit. A second pit is used as an optional single pump backup, or if the water table is too high/too much SF to cover. A third pit, I don't know unless you have a basement layout with lots of doglegs. This type of channel might negate any radon system you have.

If your house was built in 2003, there should be gravel and a vapor barrier. The radon should pull air from this "air permeable" gravel layer. If you picture a sump crock, it basically would need 3" holes put in higher than a water pipe to pull from the gravel layer. You don't need the depth or necessarily a "collection bin." So pulling from a crock even dedicated to radon has no benefits except taking up floor space.

Since you are tearing up the concrete, you should install a separate radon pipe loop. This is your chance. Connect it to the vertical pipe, and it is a passive system. After some time passes, have a radon test performed. The amount present will determine if you change to an active system - by adding a fan (in-line radon, HRV/ERV, wall exhaust, etc of your choosing). But if the level is low, the passive system is adequate and no fan is needed. Here's the EPA website on radon EPA.gov/radon

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mpoland33

Discussion Starter · #14 · Feb 4, 2020

The guy I'm dealing with is a waterproofer. He does not install Radon mitigation. His system is what is radon certified in the sense that it can tie in when a radon mitigation system is installed. We were pitched on Waterguard and chose to go a different direction. It is called a sub floor pressure relief system. It IS 4" corregated PVC that is going in.

Because he doesnt install radon, I don't really know an option I have to make a loop. What kind of PVC would I use anyway? If I loop it around the basement, where would the ending be in the sense of, how does the radon get into the pipe...just leave it open on one end?

mpoland33

Discussion Starter · #15 · Feb 4, 2020

also, I do have a lot of doglegs in the basement.

If he is digging and installing gravel into the entire perimeter of the basement, can't I just connect that vertical pipe in the gravel he is putting in?

3onthetree

· #16 · Feb 4, 2020

mpoland33 said:
His system is what is radon certified in the sense that it can tie in when a radon mitigation system is installed.

I am not aware of certification of any product/method, just installers and testers, and some states require no certification of anything radon. And best scenario is not to tie into the water drainage loop.

mpoland33 said:
It is called a sub floor pressure relief system.
It IS 4" corregated PVC that is going in.

That's marketing $peak for a pipe underground, any pipe directing water away from your basement relieves "pressure." But corrugated pipe for water is far inferior to solid pipe. And I still don't know why you'll have 3 pits if your old sump pump discharged maybe once a month.

mpoland33 said:
Because he doesnt install radon, I don't really know an option I have to make a loop. What kind of PVC would I use anyway? If I loop it around the basement, where would the ending be in the sense of, how does the radon get into the pipe...just leave it open on one end?

A water drainage system or a radon system is just a bunch of pipes, nothing too complicated. It's your call if you DIY or have him do something. Your options:

1. Do nothing, cap the existing radon stack.
If a radon test comes back high, install a small wall exhaust fan/HRV/etc and see if it lowers. As lots is still unknown about how these radioactive particles move, take the risk that letting the radon into the occupied basement is fine. Or hire a radon company to pressure test how many new suction holes are needed at various places around the basement, run PVC across the ceiling to connect them to the radon stack, and add fan in attic.

2. Reconnect existing radon stack to a sump lid.
From AARST Standard:

Probably can never achieve a sealed "vacuum" because of the new drain holes put in your CMU wall, and the poly wall sheet/dimpled cove will be an air leak point. Also lots of water in pipes and sump pump action will hinder radon airflow. If a radon test comes back high, you'll probably have to abandon that. Then follow #1 solutions.

3. Stick the existing radon stack into the gravel.
Good to be separate from water, but may not pull enough air from the far reaches of the basement. If a radon test comes back high, then follow #1 solutions.

4. Install a separate radon loop.
Perforated pipe around the perimeter in the temporarily exposed trench, connect to existing radon stack. If a radon test comes back high, add a fan in the attic and done.
___________

Basically the solutions for #1-3 is the same for someone not currently doing anything about water problems. Choice #4 takes advantage of the open trench, and is what is recommended for new construction and probably eliminates a future need for a radon contractor or any additional pipes.

There are some finer details on how you do the pipes and collection points which can be discussed if you decide to DIY.

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mpoland33

Discussion Starter · #17 · Feb 4, 2020

3onthetree said:
I am not aware of certification of any product/method, just installers and testers, and some states require no certification of anything radon. And best scenario is not to tie into the water drainage loop.

That's marketing $peak for a pipe underground, any pipe directing water away from your basement relieves "pressure." But corrugated pipe for water is far inferior to solid pipe. And I still don't know why you'll have 3 pits if your old sump pump discharged maybe once a month.

A water drainage system or a radon system is just a bunch of pipes, nothing too complicated. It's your call if you DIY or have him do something. Your options:

1. Do nothing, cap the existing radon stack.
If a radon test comes back high, install a small wall exhaust fan/HRV/etc and see if it lowers. As lots is still unknown about how these radioactive particles move, take the risk that letting the radon into the occupied basement is fine. Or hire a radon company to pressure test how many new suction holes are needed at various places around the basement, run PVC across the ceiling to connect them to the radon stack, and add fan in attic.

2. Reconnect existing radon stack to a sump lid.
From AARST Standard:
View attachment 584843
Probably can never achieve a sealed "vacuum" because of the new drain holes put in your CMU wall, and the poly wall sheet/dimpled cove will be an air leak point. Also lots of water in pipes and sump pump action will hinder radon airflow. If a radon test comes back high, you'll probably have to abandon that. Then follow #1 solutions.

3. Stick the existing radon stack into the gravel.
Good to be separate from water, but may not pull enough air from the far reaches of the basement. If a radon test comes back high, then follow #1 solutions.

4. Install a separate radon loop.
Perforated pipe around the perimeter in the temporarily exposed trench, connect to existing radon stack. If a radon test comes back high, add a fan in the attic and done.
___________

Basically the solutions for #1-3 is the same for someone not currently doing anything about water problems. Choice #4 takes advantage of the open trench, and is what is recommended for new construction and probably eliminates a future need for a radon contractor or any additional pipes.

There are some finer details on how you do the pipes and collection points which can be discussed if you decide to DIY.

Thanks for all the info. Gives me lots to think about.

IT only drained once every month but it wasnt connected to the drain tile. The only thing that sump drained was the stairwell to the basement which drained into that. My house is sitting in 2 feet of water becuase there is no sump to pull the water out. It has been sitting doing nothing. I never noticed it because it was functioning. It wasnt until recently that we found out there this is no connection for water to go into the sump.

IF I go with number 4, I'm just adding a full loop of pipe/perforated...and where does the water go? I'm assuming water will get in there right?

3onthetree

· #18 · Feb 4, 2020

mpoland33 said:
IF I go with number 4, I'm just adding a full loop of pipe/perforated...and where does the water go? I'm assuming water will get in there right?

Either 4" perforated solid, or 4" corrugated slotted, both sleeved. They also sell 3" of each, but use 3" if you are only having trouble with height. I prefer solid, but corrugated is fine for the collection pipe and may be easier retrofitting around plumbing pipes or a jagged demo of the trench. It can get water, but should be installed above the plane of the footing drain tile, so if that's doing its job any water should migrate down to there. This loop should be within 12"-18" of the exterior wall.

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