smell problem

[Kevinn]

I can't see how one causes the other.

I wanted my basement kitchen moved about 15 feet away from the previous location next to a stack so i broke the concrete and ran the PVC 4" in the ground with the proper slope to the new location, turned into ABS and a 3" cleanout and a dryfitted a 3" threaded cap to prevent sewer gas from coming in to the house. Then I tied in another PVC connection not far from the first along the same sanitary line and went the other way for an exterior drain for a walkout, left the floor partially open with an unglued 90' pointing up with a threaded cap on top.

Both tie-ins were done with tee wye connections and a 45' to aim the flow downstream in the sanitary pipe.

Neither connection is being used yet, nor are they vented yet.

Ever since this was done we've been experiencing a sewer gas smell in a powder room which is tied into a totally different stack 15 feet away from the one I tied into. It looks like theres plenty of water in the sink p-trap and the wax seal on the toilet is good.

Both connections occur within 4 feet of the stack.

If I vent one or both pipes will it solve the problem?
Should i break the concrete again and move them further from the stack?
Could I put a cheater vent in the powder room and would it help even though the room is right beside the stack?

Thanks for any information you can provide!

 

[SlowDrip]

Having a hard time visualizing the whole thing, probably because I am sick. It sounds like a venting issue to me, although I am unsure as to how your changes could have caused it. I would recommend against a cheater vent unless you are also having drainage issues in the powder room.

Have you been in the house long? Things are really really wet up here this year and I have a lot of people coming in with smell related issues. My own floor drain has a slight odor coming from it which I have only noticed once before in the last 9 years in this house.