[MADIYer11]

I'm curious about venting fixtures from the basement. All of the traps in my house (ranch style) are in the basement, not beneath the fixtures themselves. They are beneath the fixtures, but in the basement.

The vents do go to the attic, but they run off a upside down tee that is cut after the p traps.

I've never seen something like this before.

Is anyone familiar with this way of venting? Ill post a pic later.

[speedball1]

Now you have me curious as to why your drainage was run in such unorthodox way.

the vents do go to the attic, but they run off a upside down tee that is cut after the p traps

Are you telling us that after each trap that a tee was installed looking downward that ran over and connected to a vertical vent pipe? But that would make the vent a drain wouldn't it? And a plumbing inspector passed the job? Where do you live and what plumbing code do you have?
I sure would like to do a "walk through " your place.
Sounds like the Micky Mouse Plumbing Company did the job with Goofy as the foreman. Or am I missing something here? Regards, Tom

[MADIYer11]

Ok, here are some pics.

The first pic shows where the vent pipes for the kitchen and tub/lav group ends up in the wall upstairs.



This pic shows the trap for the tub. As you can see off the drain pipe for the tub, there is a upside down tee.



This pic shows the tee and the vent pipe that comes off that tee, that goes up into the wall shown in the first pic.



This pic shows the lav p trap draining into the same drain coming from the tub. Right above the lav drain, is the vent pipe that came off the tee explained earlier.



This pic shows the trap for the kicthen and another upside down tee. The vent pipe is coming off the top of that tee and over and up into the wall




This pic shows both vent pipes for the tub/lav and kitchen. They go up into the wall to where it is shown in the first pic.

[speedball1]

Number #1 picture looks normal. In #2 all I see is a drum trap going into a wye with a cleanout. I do see a tee rolled up on farther down the line for a vent but it's not upside down. I do see a problem in the background (#4) I''ll coment on later. Number #3, Same tee--
Number #4 has a iillegal "S" trap installed because the plumber was too lazy to 45 over under the drain. But the lav looks wet vented by the tub.
Number #4 is the first time I've ever seen a kitchen sink trapped by a drum trap. Don't you get a lot of clogs? That tee isn't upside down until it's pointing down.
Number #5 would be the normal transition from horizontal to vertical.
I can see where you had some of the drainage repiped in PVC and it looksw to mme like you must have "S" traps throughout that they attempted to convert to "P" traps but they sure did a lousy job on your lavatory.
To recap, I didn't see any upside down tees but the repipe job could have been done a little better, Regards, Tom