I just inspected a house that had an existing vapor barrier. The owner had tested for radon himself and had a system install. At the same time he had his crawlspace insulated and had a second vapor barrier installed over the first. The radon pipe was sandwiched in between the two vapor barriers. Is this allowed? And thank you…
Not sure about it being “allowed”, but I don’t see why it shouldn’t be.
I can’t see what it would hurt as far as the radon exhaust pipe is concerned. The PVC pipe is supposed to be sealed anyway.
It looks like the pipe terminates under this sheet laid over the pipe. Or does the pipe terminate under the original sheet? Because it doesn’t look like the sheet over the pipe is sealed at the edges. Hard to confirm without being there though.
Thanks guys. Just writing my report. I couldn’t see why it would be a problem but wanted to bounce it off someone else. Much appreciated!
Ryan, the pipe is sandwiched in between the two vapor barriers. The top vapor barrier had adhesive strips on the edges to seal the joints. It was pretty slick but there were areas that needed seams taped and weren’t.
Hopefully they perforated that lower sheet some in order to allow the air from the ground to easily travel to the pipe. Do you know what the test results were before and after the system was installed?
From the picture, I question how well that the vapor barrier is sealed. If it is not sealed, its really not working as intended.
I agree with, Jeff. Make sure to narrate the plastic needs to be sealed tight or refer it out.
Owner was not certain on the results. He could not remember.
Oh that was noted! Thanks guys.
Why would you need a second layer if layer one is performing? Things that make you go…hmmmmm
Two layers, with the pipe between, would defeat the purpose.
I agree, And why not just fixt the 1st layer. I think there is intentional concealment going on. But that is just a hunch.
1st layer likely has the pipe sealed. 2nd layer is just what? 2nd layer is because the 1st is not doing something right, likely has holes and gaps etc.
Then, there is insulation on the ground, no termite inspection window and some pink inslation board in the corner with extension cords etc. It is a mess.
The owner watched the wrong DIY YouTube video…,
The owner was a retired contractor. Very type A. He said the original vapor barrier was compromised during reconstruction of the house. It was cheaper to ad a second layer as opposed to fixing the first. I did not verify the condition of the first barrier but noted the second needed to be sealed properly. This crawlspace very clean. The extension cords you see are for heat tape for the main water line and for the radon fan. The north end of the crawlspace had two layers of 12” fiberglass insulation installed. The pink rigid you see was his attempt to keep the main water line from freezing. This house was at 6400’ in elevation with an average snow fall of 18 feet. No termites in Montana!
If the sub membrane depressurization was compromised then the top layer must take over and do the same job. The manometer would indicate a compromised barrier. But, you already identified it as a problem. You also stated he did some construction. I would recommend the radon mitigation company evaluate, repair and retest.
Not in your part! There are some 80 miles south of me.
Yes, almost anything is ‘allowable’ when it comes to remediating radon. To find out whether its worth a damn or not, place a CRM unit and get the reading.
What is allowed is what the home owner accepts.
EPA takes us here to ANSI/AARST
Simply recommend a re-test and you will have your answer…