[Chrisathome]

Hey,

so here's my problem, i have a 4" floor drain in my basement laundry room and every so often I get a really bad odor from it. When i put my hand over the drain I can feel air pressure coming out of it, so I took off the cover to investigate. The floor drain is trapped so the air isn't coming from the sanitary system, but it does have 5 weeping tile lines coming into it from all directions. I can feel the air pressure coming from these lines, a little bit from each but once it hits the floor drain the pressure builds. My question is how can i prevent this?

If i installed a backflow valve with a rubber seal would this be enough to seal it?

I also noticed that the water in the trap is pure black, i believe the air is agitating this water and creating the smell, any ideas how to clear this up?

Thanks for your help in advance!

 

[gregzoll]

Radon system in the Basement?

Your Public Works can do a Smoke test to see where the airflow is coming from.

Most likely the air could be coming from the house being over pressurized and pulling in from the outside or indoor cleanouts and other things.

 

[jmon]

A backflow valve is always a good idea. But you could have other issues as well.

If the water in the trap is pure black (sewage), sounds like you may have a partial clog causing it to back up or a venting issue. Just a thought.

I would try snaking the line first, and make sure vent/stack is clear.

Not sure about the the 5 weeping lines tying into it. I never saw that kind of set-up. As Greg mentions a smoke test may help find the issue.

 

[ben's plumbing]

get us a picture of your drain with cover off..something is not right ...

 

[Chrisathome]

ok so here are the pictures. The floor drain is on a 4" line, there's a backwater valve in my basement bathroom than all of my basement fixtures than it leads to my laundry room picking up my floor drain. When i flush the toilet the level on the floor drain doesn't fluctuate so its not siphoning so I believe the venting is good.

 

[Chrisathome]

ok so I was talking to a guy at work and he mentioned that its possibly a illegal connection tying into the weeping tile itself and the air pressure from a vent coming in. So I ran all the fixtures in the house and nothing is draining into the weeping tile, they are completely dry, it's winter so i wouldn't expect to see any water coming in. Still stumped as what it could be.

 

[ksguy]

Does the air only flow in when your furnace fan is running? If not, does the flow of air coming in increase when your furnace fan is running? My theory is that negative pressure in your house is sucking air in through the drain tile.

Your theory about the incoming air agitating the water and distributing the smell sounds like a good one.

Either way, if the bottom of that hole does in fact connect to the sanitary system, and those lines are in fact drain tile coming in from around your house, it may be an illegal setup, depending on when your house was built - see here. There are some helpful diagrams there about acceptable setups, and it sounds like a backwater valve is probably the way to go, though it looks like you'll need a permit to have the work done.

In the meantime, maybe the occasional flush with a bucket of clean water and a capful of bleach into that water will help kill off odor causing bacteria?

 

[Chrisathome]

Thanks for the reply, I didn't notice a difference in air flow when the fan was on or off. I am leaning more towards the negative air theory though. It definitely is a floor drain connected to the sanitary and is protected with a backwater valve down the line. What I'm thinking is to add a drop in backwater valve into the floor drain shown here:

https://www.homedepot.ca/en/home/p.backflow-preventer---4-in.1000514518.html

I'm hoping that because it has a rubber seal that with will stop the air flow.

I'm going to pick up some bleach tonight.

Thanks for your help!

Cheers!

 

[ben's plumbing]

40 yrs plumbing and i have never seen that type of set up......my guess is your smell is comming from those tile...maybe they are french drain run offs....which would be illegal....:surprise: