Methane Odor in Basement Bathroom

[Redwood]

Basically in a smoke test, the openings in the system are all plugged. The line out to the sewer or, septic is plugged, the vents are all plugged etc. then the last opening I usually use a roof vent the testing apparatus is set up. I make sure all doors windows etc. are closed up then the smoke generator is used to pressurize the system with smoke. people wander around in the building and look for where the smoke comes from and the leak is found. Depending on the severity of the leak(s) we either stop the test immediately or continue to find additional leaks. It depend on the volume of smoke entering the building.

Bear in mind this test is only used after checking everything that we can see and all obvious leaks are repaired.

 

[artistsnature]

Basically in a smoke test, the openings in the system are all plugged. The line out to the sewer or, septic is plugged, the vents are all plugged etc. then the last opening I usually use a roof vent the testing apparatus is set up. I make sure all doors windows etc. are closed up then the smoke generator is used to pressurize the system with smoke. people wander around in the building and look for where the smoke comes from and the leak is found. Depending on the severity of the leak(s) we either stop the test immediately or continue to find additional leaks. It depend on the volume of smoke entering the building.

Bear in mind this test is only used after checking everything that we can see and all obvious leaks are repaired.

OK, so in order to make sure all the bases are covered: is it possible that there is either a partial blockage in the basement shower, or a missing trap, that could cause this smell - and do I have to rip up the shower pan and check before I do a smoke test?

 

[Sponsor]

 

[Redwood]

No but you should be able to see if there is standing water down in the shower drain. This woukl indicate the presence of a trap.

 

[artistsnature]

No but you should be able to see if there is standing water down in the shower drain. This woukl indicate the presence of a trap.

Duh! Now I really feel like an idiot! I looked and there is indeed water in the shower trap!

I don't think anyone ever answered: Could the 1.5 inch vent stack below the top-most fixtures be inadequate for the 3 bathroom house? Would that cause the air to back up through the basement drain? Could I just tie an additional vent stack to the top floor sink?

 

[Redwood]

If there is a backup then yes the drain water coming up in the shower could smell.

Under some codes the vent would be adequate... Some want full size out through the roof. in anycase it's probably not a problem. I don't know what code you follow as your local code.

 

[Southern Man]

Somehow tossing M-80's into the septic tank doesn't seem like the way to go... ....

Somehow I don't see these having the same effect.

http://testproducts.com/safecart/product_info.php/cPath/91/products_id/165

 

[Southern Man]

Is there water in all your traps? Do you have a floor drain that is never used and the water evaporated out? Do you have a sump that collects from the footing and is that where the odor is coming from? Check all the obvious before you worry about smoke testing.

Ok you guys, now that you've put the fear of God into me about smoke tests, I'm just about ready to take out a second mortgage and call a pro! I do have a floor drain issue, which I don't think is related, but you be the judge:

There is no sump pump and the traps are all wet. There is a floor drain in the utility room on the other side of the basement from the bathroom, and there is no smell from it. Not only was it dry, but when I pried off the top and shown a light, it appears that there's a hole in the bottom of it, which then leads to another gravel pit a few feet below. This drain is right below the well tank outlet, but really does not get used, as far as I can tell. Could this effect the smell in the basement bathroom?

Here's another question: if the drains are all working, wouldn't that indicate that the vent stack, however small, is working? In that case, wouldn't a smoke test be useless?

So if it's not the vent stack and it's not the traps, WHY THE HECK DOES MY BATHROOM STINK?????

I'm a little concerned about the vent size and location (below the highest bathroom) but if the stink occurs when you're running only the dishwasher or shower upstairs then I don't see how that could be the problem. If it was then the stink would occur when other units were draining.

Is there a possibility that the dishwasher and shower are connected to a second drain stack that is not vented? A lot of stuff in this house seem cobbled together so anything is possible.

I'm also a little concerned about that unused floor drain that you mentioned that has no trap but drains into gravel below the floor. That's basically an opening to under the slab, and since you mentioned a backed up septic system and contaminated soil I'm wondering if this area isn't a breeding ground for all kinds of nasty bacteria.

Why don't you try this. Buy a cheap cigar, turn on the dishwasher and/or shower, then go downstairs with the cigar, light it, and hold it next to the floor drain, then the shower drain, and all along the edges of the shower pan. If this part of the drain system is unvented then air will eject from one or more of these openings, and you ought to be able to see air movement with the cigar smoke.

Redwood might be able to help you with the brand of cigar to buy.

 

[Redwood]

Redwood might be able to help you with the brand of cigar to buy.

I wouldn't have a clue...
I don't smoke cheap cigars and don't advocate smoking in customers homes...

 

[Southern Man]

Here's where I'm going with this floor drain that empties into gravel below your floor slab.

http://www.fantech.net/radon.htm

Regardless of radon in your basement or not, this type of fan could be used to vent that space. You should have gravel under your slab as well, so this would put the entire area under the slab under a vacuum, which may take care of the odor problem entirely.

I've had one of these running for 8 years to remove radon from my house and never had a problem with the unit. I just installed a second one at my cabin to take care of radon there. The most difficult part of the installation was cutting a hole in the basement wall for the discharge.

Maybe you can connect a big shop vac to that drain, set up the machine outside with a long hose, and run the shower upstairs to see if the concept works.

 

[artistsnature]

I'm a little concerned about the vent size and location (below the highest bathroom) but if the stink occurs when you're running only the dishwasher or shower upstairs then I don't see how that could be the problem. If it was then the stink would occur when other units were draining.

Is there a possibility that the dishwasher and shower are connected to a second drain stack that is not vented? A lot of stuff in this house seem cobbled together so anything is possible.

I'm also a little concerned about that unused floor drain that you mentioned that has no trap but drains into gravel below the floor. That's basically an opening to under the slab, and since you mentioned a backed up septic system and contaminated soil I'm wondering if this area isn't a breeding ground for all kinds of nasty bacteria.

Why don't you try this. Buy a cheap cigar, turn on the dishwasher and/or shower, then go downstairs with the cigar, light it, and hold it next to the floor drain, then the shower drain, and all along the edges of the shower pan. If this part of the drain system is unvented then air will eject from one or more of these openings, and you ought to be able to see air movement with the cigar smoke.

Redwood might be able to help you with the brand of cigar to buy.

BRILLIANT!

Actually, it's the upstairs shower, the dishwasher OR the washing machine that cause the stink - all of which (plus the basement lavatory) drain into the same 1.5 " horizontal pvc pipe that leads directly into the bottom of the waste stack.... I'm not sure where the vent stack comes off the waste stack, but I suspect that it connects to the main floor fixtures (it comes out the roof above that bathroom).

The basement bathroom was definitely a shoddy job put in 15 years ago - I just replaced all the fixtures after tiling the floor, including the shower stall. The stall itself was just a thin piece of linoleum glued to the studs on the cinder block - no insulation, no backer board (talk about a cold shower!). When I first bought the place a year ago, the shower handles had been taken off and shelves installed in the shower - above the 3 inches of dried excrement!

Anyway, I assume that the shower is tied into the main waste stack, so it would vent up there, right? Is it possible to add a vent stack to the shower? Is venting into the wet waste stack the problem? (I'm getting out of my league here...).

I will try the cigar idea, but just FYI the house failed the radon test, too, and I have a system installed....

Thanks again!