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bryan
sewer venting problem

I'm having a problem lately with sewer gas venting into the bathroom from either the base of the toilet or the tub drain. It comes from the shower/tub drain only during use when the wind is from the South (vent is on the N slope of the roof). Also, from the toilet base when the wind is from the South. My guess is that the wind is pushing the gas back down the vent & into the system so I'm considering putting some sort of guard over the roof vent; maybe a 90° or 45° PVC elbow. I also notice a hint of the gas coming out of the bathroom heater vent when the furnace is on - no matter what the wind direction.

This is a new problem this year after tiling over a hardwood bathroom floor this spring & insulating the attic last winter so I'm trying to make a connection with how these things might have contributed to this new problem. The toilet & tub sit higher now due to the tile & backer board but the toilet isn't leaking water so I don't think that's the issue. It is a claw foot toilet so the p trap is below the floor. I am on a septic system but don't have any issue with the drains not draining so I don't think it needs pumped. I just can't figure why it's only a problem when there is a South wind but can only think of the above mentioned fix of using the PVC elbow??

Any other ideas would be appreciated.

bryan
Re: sewer venting problem

that should read claw foot TUB...not toilet. :o

canuk
Re: sewer venting problem

I have seen this before where someone had punctured a vent pipe when they were screwing a cabinet to the wall.

From your description it is something that was done since your remodel. Curious what seal did you use for the height difference of the toilet?

havanagranite
Re: sewer venting problem

after putting down your new tile it raises the toilet a little higher, did you use an extension that sits ontop of the old seat and raises the wax ring? your wax ring probally has flange on it that looks like a big funnel, so that would keep the water from pouring out onto the floor but would still alow the sewer gasses to escape. they make extension rings that you can buy at lowe's or most any supply house that sits below the wax ring and raises it up and makes a good seal.

bryan
Re: sewer venting problem

A plastic collar (exetension ring)was screwed on top of the existing collar to make up the height difference from the tile & backerboard.

If this were the only problem why would the tub drain be venting sewer gas only when it is used on days the wind is from the South? I keep suspecting the need to guard the vent on the roof. Either that or I have two separate problems. It's frustrating.

havanagranite
Re: sewer venting problem

bryan I couldn't say for sure with out actually looking, though I have seen where air coming down the pipe actually caused the water in the trap to evaporate which allowed sewer gas to come up but even then that took a couple of days of the wind blowing and the tub not being used for it to do that because every time the tub is used it refills the trap. now that might be a thought you might check to see if the trap either has a hole in it, (some of the older cast pipes do spring leaks right in the bottom.) or it might be that the work might have made some joints loose

bryan
Re: sewer venting problem

Makes sense that there could be a leak though I didn't see one. Wouldn't the running shower fill the trap and stop this even if there were a leak? The smell is immediately during & after running the shower and only when the wind is from the South.

Crazy, huh?

havanagranite
Re: sewer venting problem

if its a cast pipe the hole is quite often right on the bottom of the trap and that would drain the trap right away it wouldn't hold any water

bryan
Re: sewer venting problem

The plumbing is all PVC. When I was in the crawl space looking for leaks I observed no leaks with water running & draining thru the trap.

The house is a one room school house built sometime around 1885, plumbing and modern electrical wiring was installed around 1990 when the place was remodeled into a home. I've been here for about 4 yrs but never noticed this smell until this yr. Maybe it was always there but the wood floor in the bathroom helped absorb some of the odor that the new tile floor doesn't? Still doesn't explain why it's only noticeable when wind blows from the South. I have gotten on the roof snaked out the vent. It didn't seem to be plugged and the snake came back wet.

bryan
Re: sewer venting problem

Maybe this sheds more light on the problem:

Came home a bit ago & there is a 20mph South wind. I could smell sewer gas when I came into the house. I washed a load of clothes and the smell became MUCH worse. I then got into the crawl space...nothing is leaking anywhere nor does it appear there has been a leak anywhere. The smell not only comes from the toilet base but also near the kitchen sink. The drain near the washing machine smells too. No smell at all in the crawl space. It appears to me that for some bizarre reason the sewer vents everywhere but where it should when the wind blows from the South. Any other time ther is no real problem - except that I can smell some gas (not real bad) coming from the heater vent in the bathroom when the furnace is on, regardless of wind direction. Otherwise the air vent does not smell.

What is going on??? I guess my question is...can any harm come from putting a 90° or 45° PVC elbow on the roof vent?

bryan
Re: sewer venting problem

I think I might be on to something. This might all be due to the toilet wax ring. While it is not leaking water, gas is definately escaping thru it & it may be the cause of everything else...I hope anyway. This issue must stem from the tiling of the bathroom floor. The original flange sat just above floor level -if i recall right. The backerboard and tile of course raised the floor height & I used a ring/collar to make-up for the height difference - I thought anyway. I'm wondering now if perhaps the ring was not thick enough. If so what is the option? Two collars? Are collars available in different thickness?

I think I need to reseat the toilet with a thicker collar in order to get the height just above the new floor level. Am I on the right track here?

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