I have a 4in open drain in the basement.
It's been bone dry for the year I've owned this home and not been a problem.
Lately sewer gas smell has been coming from the drain though.
The drain has no trap, I've run tons of water through it and it just drains straight out.

I don't need the drain, my guess is that it used to be a utility sink that was removed, as I have a sump pump and a p-trapped drain for the washer.

Can I plug this?
If so what is my best option for plugging it?
Is gas build up a potential problem?

Would appreciate any advice.

plugging it depends on how you want it to look.
if you can have something sticking above the floor slightly then you can use an expandable test plug.
if you want a nice clean finish even with a cement floor, stuff the pipe with newspaper. leave room for 1/2 inch of cement on top. pour a nice soupy mix on top of the newspaper.
mark where it is so you can bust it open if you need.
make sure to use newspaper because if it ever falls in it will disolve with water..

Thanks for responding.

I'm perfectly fine with a test plug, after looking it up it seems that's what they put on my clean out as well.
My main worry with it was that it would build up gas.
Not concerned about the aesthetics.

No, the gas will escape via the vent(s) on the roof.

Awesome.
Thanks for the advice.
Bought the test plug.
No more sewer!



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