Bathroom remodel, plumbing questions

[Karyneliz]

We just tore out our basement bathroom to redo it.. And there is so much plumbing that we cant make heads or tails. Hoping someone can shed some light on if its correct or not. We have two pipes running down from our mainfloor kitchen sink (right of picture) the one is the drain that runs directly into the basement floor, the plumbing for the bathroom sink also drains into here.

The second pipe connects to this thicker stack to the left of the photo, which our laundry tub also connects to. Im not sure what this is for... My thought is, that it is the vent for the fixtures.. As it runs and connects to the kitchen sink then out the wall, presumably up out the roof.. If it is a vent how can i tell of my toilet is connect to it?

Then the drain for the tub is located directly in front of the thicker stack

Any insight would be helpful

 

[Diehard]

Agree that the line running along the wall from left to right would be the vent for the drain line on the left.

Are you sure that the other line that goes through the top of that wall is from your main floor kitchen sink drain? If it is then it's also serving as a wet vent for that basement sink trap, from what I can see. I suppose if you wanted to confirm that, you could open that cleanout plug, located about a foot above the floor, and look for flow when the kitchen sink is used.

But in any case, was that one vent line the only pipe you didn't know for sure what it was?

 

[Karyneliz]

Thanks for the insight. Do you think the toilet is connected into the same drain and therefore using the same vent? Is there anyway i can check this without having to break up the concrete?

Instead of the bathroom sink using the drain as a wet vent... Should we run piping from the sink to the existing vent?

Also, its hard to see, but there is a short drain coming off the thick stack on the left, it has an orange test cap.. Any idea why this is?

 

[Diehard]

Thanks for the insight. Do you think the toilet is connected into the same drain and therefore using the same vent?Could be! Toilets are somewhat unique in that their design is based on siphoning. After that I don't think the the vent is required nearby. If it worked without problems before, I wouldn't worry about it. Is there anyway i can check this without having to break up the concrete? Don't know. Metal detector??

Instead of the bathroom sink using the drain as a wet vent... Should we run piping from the sink to the existing vent? Wet vents under certain circumstances are acceptable under the codes. As long as it didn't draw out the sink traps water seal, it's probably okay.

Also, its hard to see, but there is a short drain coming off the thick stack on the left, it has an orange test cap.. Any idea why this is? I had assumed it was probably some earlier abandoned connection for who knows what.