Noticable septic smells in house....?

[Richard]

I think we finally narrowed it down.

Setup: basement utility room/bathroom. Washer/dryer are in this room. The kitchen was originally going to be directly above this room and as typical, my wife decided to move the kitchen midway through building the house :confused2:

After the house was done, we noticed some septic smells... long story short, it turns out the drain for the washing machine (which is located INSIDE the 8" blocks) had a vertical pipe and this pipe was going to be the drain for the kitchen sink which would have been located essentially, directly above.

This pipe stub was (guessing) a 2" pvc pipe. It extended up about 5' from the drain of the washer and basically, only went through the block at the top of the wall and through the plate (2x8?) that was on top of the plate.

Unsure what to do, I figured I needed to give it some volume of air and also keep it closed. The geography of the setup totally disallowed me to vent this outside since I now have french doors directly above and my back patio on the side. This is a log house so I don't have hollow walls to deal with either.

I got maybe 40' of 2" pipe and inside the ceiling, snaked it from this stub across the room, into the other larger room and merged this pipe into what is the drain pipe for the kitchen.

Since this is an 'air' pipe, I held (mounted) it as high in between the joists as I could and when I merged it into the kitchen drain pipe, it came to this pipe from above.

Meaning, water draining from the kitchen could NOT enter this pipe since it angled up at that junction. This way I would never have an obstruction.


Enter today: we are still getting some septic smells in this room. It comes from this closet where the washer/dryer are located.

I'm now wondering if the fumes are coming from this newly installed vent pipe.

I suppose I could have installed a 1-way valve (??? don't know)

I just hate the idea of a valve being installed in the walls where I might not have access to it if it ever failed.

What is also making me scratch my head is why isn't the P-trap on the washing machine doing it's thing?

Last night, I had to pull the washer out to clean the input screen to it. When I put it back I noticed the actual drain pipe from it seemed to be pushed WAY down in the P-trap.

Is it possible to have the outlet hose from the washer too far extended into the P-trap, such that the velocity of the water from the hose will help create air movements through the trap??

Could pulling the drain pipe out one or two inches help keep a plug of water in there?

As best I know, there are now NO other open pipes what so ever. This is accurate unless the installer has an open stub INSIDE the block wall that I've never seen. Although I suppose that's possible, I don't see that happening. I'm 99% convinced it's coming from the P-trap

 

[zzvyb6]

Check to see if the brand and model of your washing machine draws some water back into the pump from the drain hose as part of a cleaning routine. Its not a lot, just a small amount. If so, it may have emptied the trap and you have an open vent. That's how my my machine works.

 

[Richard]

now THAT is a wild idea that I would have never thought of!

If that is accurate, how might you get around it... simply raise the outlet level of the discharge hose so it can't suck up all the water?

 

[crusty 1]

Richard, you may be right about pushing the drain hose to near the trap,they have a preety high volume when discharging.Move it up and try,didn,t cost a thing:thumbsuplease be sure your traps are filled with water ,sewer gas is as deadly as "the gas chamber".Years ago I was over come and it,s such a slow process you notice no smell or ill effects.I was lucky that a friend happened to call me and thought I wasn,t making sense so he came to check,long story short,some time outdoors and a bit of a headache all was well.Could have gone the other way.Dave

 

[inveresk]

Adding an air admittance valve (also called a durgo) might cure the problem but it does need to be able to draw air and it can't replace the main vent to the outside which is usually at the head of the drain. However, any branch vents that are needed can usually be replaced with durgos. The durgo has to be higher than the highest flood point on that floor, usually the wash hand basin outlet.

If your durgo is in a sealed cavity, you'll have to add a grille or some device to allow the durgo to draw air otherwise it won't work as it should (in your case the cavity can't be that well sealed or you wouldn't notice smells).

In some areas, BC for example, the building code doesn't allow durgos. That also applies to a number of other useful devices such as running traps, bell traps and bottle traps. In these circumstances, always with the client's written consent, I simply get an occupation certificate for the installation as required by code then make the necessary changes to suit the owner. If he ever puts the place on the market, then he'll have to make a sellers declaration re the non code items.

 

[deerefan]

make sure all p-traps are full of water. had this problem in a house and realized the p-traps were dry (house was new construction, water never ran)

 

[chipsndust]

Check to see if the brand and model of your washing machine draws some water back into the pump from the drain hose as part of a cleaning routine. Its not a lot, just a small amount. If so, it may have emptied the trap and you have an open vent. That's how my my machine works.

make sure all p-traps are full of water. had this problem in a house and realized the p-traps were dry (house was new construction, water never ran)

This happened at my camp. Turned out that the washing machine (which was rarely used) trap was empty. Either use it, or pour water down the drain to fill the trap.

 

[retiredmgn]

Gave the original post a good read but was unable to draw a visual in my mind. A few thoughts -
For a P trap to be effective there is a max distance from the stack allowed. This is stating the obvious but it sounds like the trap is getting sucked dry. A lot of variables here but all specs are available on the web. Might need to add a new stack to stop the suction.
There are many ways to try to jury rig something that isn't doing what you think it should be doing. In my experience (read as experiences of, "I can fix this by adding this") you just can't fool this kind of stuff into working. That's why we have plumbing codes in building.
What I've found is 'doing it by the book' works. As a younger guy that was a bitter/expensive pill to swallow.
"I'm a man. I can change. If I have to".