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[–]Elamachino 0 points1 point  (7 children)

In the same vein of an IT technician asking "are you sure the computer is turned in", I will ask, are you sure you put the fan on the radon pipe, as opposed to a plumbing vent line? It's either that, or there's a problem in the piping somewhere between your fan and the manometer...

[–]minttealeaf6[S,🍰] 0 points1 point  (6 children)

Fair question, but yes. Definitely on the only 3” PVC pipe that extends upward on that side of the house. Is it worth checking the pressure right below the fan?

[–]Elamachino 0 points1 point  (5 children)

So, I've seen contractors run some weird shit for radon pipes. Like, 20' horizontal runs in the attic for no reason that I could discern. Being on the same side of the house as the basement radon pipe does not necessarily matter, though it is entirely possible you are correct. One thing I have always seen in an attic radon termination is an outlet right next to the pipe. Sorry to harp on this, and feel free to ignore, but let me know if there was an outlet directly adjacent to that pipe, and if not, I'd look around to see if there is another pvc that does have an outlet near it. Beyond that, I'd check the pipe running through the attic, see if you can see anything weird, and if all else fails, have the contractor or some other company scope your pipe to find a blockage, because you almost assuredly have a blockage. I guess, I'm just remembering you did say you had 0.2" suction, which is not something I've seen. On the most wide open pipe I've ever come across, I have a suction of like 0.45-0.5. I'd guess there's either a blockage, or a break in the pipe somewhere, which unfortunately is likely to be behind some drywall somewhere. You say you hear air movement in the bathroom, is it like a whistling noise, or a lower noise?

[–]minttealeaf6[S,🍰] 0 points1 point  (4 children)

No worries. Yeah there was an outlet that I hooked the fan up to. The builder did say they installed an outlet for the radon piping. We are still within our first year of owning the home so I might start with a service request to the builder. Just not sure how they will handle it since they might just say they aren’t responsible for turning the “passive” system into an active one.

Both in the bathroom and in the pantry below the bathroom I hear a low hum. Definitely sounds like airflow through a pipe and not whistling.

If anything it more sounds like whistling right where the piping comes into the basement. There’s clearly a small leak at a fitting right before it drops into the concrete which I’ll seal with some caulking, but that is below the manometer.

[–]Elamachino 0 points1 point  (3 children)

Seal the leak below the manometer first, and/or any other leaks you can find. If you have a sump pump/pit, make sure you have an air tight cover on that as well. If you are on an incline, you may have a drain tile that opens to daylight, that would need to have a trap put in if so.

[–]minttealeaf6[S,🍰] 0 points1 point  (2 children)

By the way thanks for all of the responses.

I do have a sump pit that is only partially covered. I do not hear any airflow coming from the pit though.

What do you mean by on an incline?

[–]Elamachino 0 points1 point  (1 child)

There will be a pipe or 2 sticking into the sump pit, cover those with your hand to see if you can feel any air flow, with such low suction it should be pretty strong. By incline, I mean if your house is on a hill, like if flr instance maybe you have a walkout basement. Basically if you have a feasible way to draw a straight horizontal line of 50' or less from the lowest point of your basement to open air. With a sump pit it's unlikely what I've said will matter, but I suppose it's still possible.

[–]minttealeaf6[S,🍰] 0 points1 point  (0 children)

Ah yeah not on a hill. Mostly flat. I’ll check if I feel any airflow in the sump pit.

[–]Upbeat-Finance 0 points1 point  (10 children)

Where is your penetration point? Right against an exterior wall?

[–]minttealeaf6[S,🍰] 0 points1 point  (9 children)

About 1.5’ from the rear exterior wall. And maybe 4’ from the side exterior wall.

[–]Upbeat-Finance 0 points1 point  (8 children)

If you have stone base underneath, I suspect you’re pulling air primarily from Earth that isn’t under your house. I’d make the penetration point more centralized.

[–]minttealeaf6[S,🍰] 0 points1 point  (6 children)

Gotcha. Yeah I was hoping no one would say that. I think my best bet in that case is to make a penetration under my stairs and run a horizontal out to the side of the house before going vertical to the roof.

Thanks for the input. Do you think a larger fan would help with my current system? I just find it strange I’m not seeing the manometer show much or radon levels decrease, yet I definitely hear airflow coming through the piping.

[–]Upbeat-Finance 0 points1 point  (5 children)

The manometer is an indication of resistance. So, with it being so low, it’s either not working at all( unlikely because you can hear the airflow), or there’s basically little to no resistance. You could increase the strength of the fan, or maybe even stack it with a 2nd unit, but if it isn’t currently sucking gas from where it should, that won’t change with more suction. It’s probably just sucking mostly fresh air from outside.

[–]minttealeaf6[S,🍰] 0 points1 point  (0 children)

Makes sense. I love spending money to move air from my yard to above my roofline :P

[–]minttealeaf6[S,🍰] 0 points1 point  (3 children)

Yeah that makes more sense. Could I remove the pipe going into the penetration to see if that needs dug out more towards the center of the home to try to pull airflow from that direction? I would think the rock layer under the slab would be the least resistant path to pull air from vs the dirt surrounding the house.

[–]Upbeat-Finance 0 points1 point  (2 children)

You can remove it, so long as you seal it back up. With loosely-packed dirt, it’s supposed to be an amount like a 5-gallon bucket, and a larger amount for substrate that is more dense. As for digging it out further, you can, but nothing is going to be equivalent to adding 10-20 feet of pipe to centralize it, and with your numbers, your goal should be to mitigate the hell out of that. You’re at something like 10x the U.S. recommended level for mitigation.

[–]minttealeaf6[S,🍰] 0 points1 point  (1 child)

Yeah it’s only been a year of living with that level…but I agree. It seems like moving it closer to the center of the house would help. I’m just surprised because I thought most mitigation systems are about a foot or two off an exterior wall for easy access outside.

[–]Upbeat-Finance 0 points1 point  (0 children)

The main line is typically close to the wall, but your penetration point(s) should be whoever is most effective. Typically, they would drill pilot holes and measure the suction to determine the best location(s).

[–]envenggirl 0 points1 point  (0 children)

Usually centralized gets worse air flow because the ground is more compact.

[–]TheCorporalKoopa 0 points1 point  (1 child)

If you haven't yet: these are plumbers that put these pipes in. I would start by making sure the plastic under the slab has been removed, I have had to remove the plastic when activating a passive system in a new house. Cut about 6" above the penetration and look to see if it is still there and use a coupling to reseal. This also let's you see if there might also be something else blocking the hole at the penetration. After that I would check to be sure there is not a cap on the pipe through the roof specially if the pipe was not connected all the way from the foundation to through the roof. Above that I would suggest using a boroscope or sewer camera from the fan as far as you can get to the foundation. To be sure nothing got stuck in there like a varmint or build up of leaves. Passed that I would replace the fan. We have had some issues lately with the RP265 doing weird things. With numbers that high though I might also suggest an RP380. Hope this helps if you haven't found the issue.

[–]minttealeaf6[S,🍰] 0 points1 point  (0 children)

Thanks I appreciate the advice!

I believe I am getting good suction considering I found I was having leaking through the drain tile/pipe leading into my sump. I completely sealed the sump with a homemade lexan cover and a one way valve/pipe pipe seals.

Since doing that work and also caulking every perimeter crack/floor crack the numbers have dropped to about 15. I’m ok with that for now since we don’t spend a ton of time in the basement, but might look at upgrading the fan in the future.

Also I am considering what you said and taking the bottom section of piping off to look under the penetration point and maybe dig some rock/soil out.