My house is approx 5 years old. Had basement (walkout) plumbing roughed in. Was carefully inspected for design, but somebody could have dumped concrete down a vent pipe for all I know. There are two vent pipes for the downstairs bath - one between the toilet and shower, one between toilet and sink (both run up the interior walls and tie in together in the attic). We just finished all drywall and fixtures. Everything works fine: toilet and sink drain and flush OK.

Noticed that when upstairs washer empties, which dumps a big flow down the main vertical stand pipe, the toilet sucks air and water level lowers. The toilet is upstream of the stand pipe (in other words, the "emptying order" in the basement is toilet first (in the front of the house) to main floor drain pipe, then verticcal standpipe from upstairs to floor level main drain (about 1/2 way between the front and back of the house) in basement, then out via gravity to septic field behind walkout. It is like the washer dump creates a vacuum in the main drain that affects the toilet.

From what I have read on your most helpful site, this is probably a vent problem of some sort upstream of the toilet. We have two primary vent stacks on the roof. The one servicing the toilet in question supports the kitchen, laundry room, and basement bath (only). This recent installation is the first time the roughed in basment vents would be used.

Looking from the attic, the vents "spider out" to the various areas from roof vent in question. So I don't see how we can snake it from the roof or maybe even the attic. How would you know which branch you are snaking into? What are your suggestions for diagnosing and correcting this problem, preferably without having to tear out any of the new bathroom's drywall?
Are we seeing a vent problem with the toilet or the washer? And finally, how serious of a problem is this? Does it make sense to hire someone with a "scope" snake (still not sure how you would direct it to the correct vent, though?)

My husband is a resourceful do-it-yourselfer who can tinker with this on weekends if he has some suggestions on what to do. The wife (me) just wants everything to work correctly with minimal fuss and destruction.

Hi Judy,

What you have in your attic's called "reventing". It's used when the builder doesn't want a bunch of vent pipes sticking out of the roof and wants to hide them by reventing in the attic and bringing the roof vent on the back side of the roof. This may be great for looks but it's bad for the plumber that has to snake out a vent.
We have to go up in the attic and determine what vent services what. When we find the correct pipe we have to cut it loose and snake from the attic. After we snake the vent we have to reconnect it. We usually use NO-Hub Bands (see inage) to reconnect. You will most likely have to get a plumber to figure out which vent to cut into. Good luck, Tom

Judy,
We don't have the resources to recommend outside contractors. If you decide to do the job yourself I can tell you how to locate the right vent but it's a real hassle to snake a vent from the attic. Regards, Tom

Well gang, after Speedball's last answer, I called in a plumber after first explaining the situation carefully over the phone. I was assured that the vents could be snaked out from the attic. When the plumber arrived, we had to go through the whole diagnosis thing (which may not be so bad), but when it boiled down to that multiple vents in the attic would need to be cut to diagnose/clear the clog, the plumber labelled the necessary procedure a "major problem" and said that it would be cheaper to knock out the drywall on two floors and redo the entire vent system than try to snake it out. I pushed to get a quote for the snaking, and was finally told $180 per hour plus $45 per cut with no guarantee of success in finding the clog. He estimates a total around $2000.00. I was shocked. Is it that big of a deal to snake vents from the attic? This person was from a major company with access to camera scopes, etc. I thought the problem was potentially messy, but not impossibly difficult or anything. Any thoughts out there?

Quote:

---

Originally Posted by judy haas

Well gang, after Speedball's last answer, I called in a plumber after first explaining the situation carefully over the phone. I was assured that the vents could be snaked out from the attic. When the plumber arrived, we had to go thru the whole diagnosis thing (which may not be so bad), but when it boiled down to that multiple vents in the attic would need to be cut to diagnose/clear the clog, the plumber labelled the necessary procedure a "major problem" and said that it would be cheaper to knock out the drywall on two floors and redo the entire vent system than try to snake it out. I pushed to get a quote for the snaking, and was finally told $180 per hour plus $45 per cut with no guarantee of success in finding the clog. He estimates a total around $2000.00. I was shocked. Is it that big of a deal to snake vents from the attic? This person was from a major company with access to camera scopes, etc. I thought the problem was potentially messy, but not impossibly difficult or anything. Any thoughts out there?

---

I don't know Judy,
"we had to go thru the whole diagnosis thing (which may not be so bad), but when it boiled down to that multiple vents in the attic would need to be cut to diagnose/clear the clog, the plumber labelled the necessary procedure a "major problem".
What's to "diagnose"?? There are two vents to identify and snake. The washer vent and the pipe that vents the toilet that the bowl level gets sucked down.
Every time I had a blockage in a drain line and all the vents revented back in the attic I just Located the correct vent pipe by simply checking where the vents came up out in the attic as per against where the fixture in question was located in the house. I then took a Saws-All, (reciprocating saw) cut the vent and went down the opening to clear the drain. I have NEVER had a call that involved attic revents that I wasn't able to clear the line and be out of the house in under 1 1/2 hours. While it's not the handiest thing to snake from a attic, to suggest that the entire vent system will have to be toen out and replaced for a simple clog is nothing less then criminal. $45.00 to cut open a 2" vent pipe and $180.00 per hour per man to snake the pipe is outrageous and is a total rip. Try another company, this one sounds like the owners want you to finance a vacation to Disney World up in Orlando. Now I'm not saying that you wouldn't have a major problem if you do find cement or tile mortar in your vents but you have to snake them or run a camera through to find out. These guys didn't even try. When I hear stories like this it makes me ashamed of my trade. Please keep me in the loop in this. Regards, Tom

Speedball1: I cannot get the thing to let me "comment" but thanks so much for your prompt reply. I can tell by reading through this forum that you are the "resident expert", so I feel better. It is alarming when someone essentially tells you that your almost new house is badly broken.

I thought the whole thing sounded out of line to my common sense, but this guy was supposed to know his stuff. I called my builder tonight (probably should have done this in the first place, but hated to bother him after 5 years) and he said that he builds a quality house and that the claims made about the system needing rebuilt rather than snake a vent made no sense to him. He offered to send his current plumber out next week to fix the problem.

Whatever, I would learn to live with some water loss (it does not "go dry") rather than spend the amount of money suggested. Thanks again.

Hi Judy,
Take the builder up on his offer to send his plumber out to repair the problem.
His man would know more about the installation then the "fast track plumbers" that wanted to tear up yoir walls and replace the vents. Let's look at that for a minute. They wanted to replace the vents so they could snake the lines. OK! Now they've tore up your house and charged you two grand for it. ( I take it that $2000.00 includes repairing, drywalling and repainting the walls as well as replacing the vents, and what did they have planned for the attic?) But wait! When they finally got around to snakeing the lines they found cement in the base at one of the stacks. You think that their two grand charge was something? Just wait till you see what they'll charge to jackhammer up the floor and replace the bend at the base of the stack. Can you say, "sticker shock"? Let me know what the builders plumber has to say.
Thanks for keeping in touch. Tom