Find out why a radon pipe should never terminate in the attic. Get tips on extending it through the roof and putting a proper plumbing vent and flashing sleeve around that. If this problem exists in a house you are looking to buy, bring it up during the negotiation process.
LESLIE: John in Colorado, welcome to The Money Pit. What can we do for you today?
JOHN: I had a question about the venting of a radon installation, a radon pipe.
JOHN: And the house I was looking at had this pipe from under the slab.
JOHN: Actually, it wound up in the garage and then it went up into the attic of the house and in between the garage floor and the attic was an inline fan.
TOM: (overlapping voices) OK. Right that’s correct.
JOHN: But the pipe terminated two feet into the attic.
TOM: Oh, so it didn’t go through the attic to the outside?
TOM: Oh, well that’s a mistake. Yeah, everything was correct up until you got to the fact that they left the pipe in the attic. No, you want that to go up through the attic, through the roof just like a plumbing pipe would.
TOM: And typically it turns down, like U-shaped at the top, so water doesn’t get into it.
JOHN: Well, they had seven or eight vents in the roof in that attic.
TOM: Well, maybe they felt like there was enough ventilation in the attic. But the fan is supposed to terminate outside. You’re not supposed to dump it back into the house in any way, shape or form. So I would take it – and you can simply add to it and you can bring it up through the roof and you put a proper plumbing vent and flashing sleeve around that and then terminate it above the roof.
JOHN: OK. Oh, just another expense. (Leslie chuckles)
TOM: Yeah, well you know what? You said you were buying this house?
JOHN: I was looking at it for my daughter.
TOM: Make it part of the negotiation. I don’t think it was done right.
JOHN: Yeah, OK. Well, that’s reasonable.
TOM: Certainly is.
JOHN: Alright, well I guess I could even put it into that vent and have a hole there.
TOM: What vent?
JOHN: Well, there are six or seven or eight roof vents.
TOM: Oh, terminate it near one of the attic vents?
TOM: I would just run it up through the roof and terminate it above the roof. I would not try to jury-rig it by sticking it near one of the other vents. That’s not the way they’re supposed to work. You don’t know if those vents are going to be pressurized or depressurized, depending on the airflow over the roof structure itself. So I would keep the radon vent away from that, go right up through the roof and terminate it the way it was supposed to be done in the first place.
JOHN: Good enough. Truly appreciate it.
TOM: You’re welcome. Thanks so much for calling us at 888-MONEY-PIT.