Cleanout problems solved, now come vent problems

I took out the old cast iron pipes this weekend, and put together another dry fit. I have both first floor bathroom and the on-going basement bathroom. The basement shower-tub need a vent, but I don't know I should vent through a new revent to roof or anywhere in the existing waste-vent in basement. I learnt the code requires a vent above at least 6" of the highest fixture, but is it only required when critical distant was exceeded? Some plumber told me I need a revent for the first-floor sink, but I don't think the sink to vent distant exceeded critical distant. For safe, I cut out a section of vent pipe in attic and inserted a double Tee, made ready for at leas one 1 1/2 revent pipe whenever needed.

Overview picture:
http://picasaweb.google.com/abrahuang/HouseBasementPlumbing/photo#5118770661953697250
Upstream view:
http://picasaweb.google.com/abrahuang/HouseBasementPlumbing/photo#5118770683428533746
Tee for revent in attic:
http://picasaweb.google.com/abrahuang/HouseBasementPlumbing/photo#5118759160031278530

abrahuang said:

I took out the old cast iron pipes this weekend, and put together another dry fit. I have both first floor bathroom and the on-going basement bathroom. The basement shower-tub need a vent, but I don't know I should vent through a new revent to roof or anywhere in the existing waste-vent in basement. I learnt the code requires a vent above at least 6" of the highest fixture, but is it only required when critical distant was exceeded? Some plumber told me I need a revent for the first-floor sink, but I don't think the sink to vent distant exceeded critical distant. For safe, I cut out a section of vent pipe in attic and inserted a double Tee, made ready for at leas one 1 1/2 revent pipe whenever needed.

Overview picture:
http://picasaweb.google.com/abrahuang/HouseBasementPlumbing/photo#5118770661953697250
Upstream view:
http://picasaweb.google.com/abrahuang/HouseBasementPlumbing/photo#5118770683428533746
Tee for revent in attic:
http://picasaweb.google.com/abrahuang/HouseBasementPlumbing/photo#5118759160031278530

Click to expand...

I would change the 4"X1 1/2" double to a 4"X2" double for your vents I would run the new vent from the bathroom in the basement up. This way you can not deal with trying to connect anything in between. One shot all the way.

vents

As far as the pictures show, neither the sink or tub/shower is vented, so yes they will need their own vents, and it has nothing to do with critical dimensions, it has to do with where, and how, they are connected.

congratulations, Abraham, you have fixed the toilet drain situation by using a Wye, as suggested to you in your previous thread. This is Good News #1.

If the slope is correct, then it is even better Good News.


But to make Good News #2, I must tell you what to change, now.

In that previous thread, i wrote one big post (which you quoted entirely in a later post). Then, the next person posting after my post confirmed to you that the tub-shower could NOT be drained as you had shown it at that time. That is what I said too.


Now, I see in the picture #1 that you linked to above, that you have maintained this bad piping connection, and now you have read someone commenting above saying the same thing in their post.

When will it sink in? When will it be clear? I hope new people will tell you the same thing, in words that you can follow. In case their words and my words are not clear. Read this out loud: your tub/shower drain is No Good like you have shown it.

To make it right, you must go back to look at how the tub/shower was connected at the first post of your first thread, where it was piped together with the sink FIRST before they both connected to the next big pipe (called stack). The way it was built before you changed anything was a Good Way to Do It.

So, rewind the tape, and copy that, because it was good. Turn the tub-shower P trap "tailpiece" towards that sink drain, and connect it to the sink drain. Do not put the tub-shower drain into the stack Not there where you have shown it, in your picture, as it is today. (Why? Do you want to know why? It's because the sink drain is already vented.)

Do that, and then post picture showing sink-and-tub-shower together. That is called a "bathroom group" in case you want to read a lot more about it.

david

My biggest confusion is the 3" vent/stack. it comes vertical from roof, connected nothing on the way, then down to basement and made a 90 turn to horizontal. Does this vent count? Where it started not be regarded as a vent?
From the replies, I learn that the sink connected to this horizontal section is not considered "vented". Is this means that the 3' vent connectd through Wye only works for the toilet?

After the horizontal pipe makes another turn down vertical, is it still a vent/stack? I am asking because I have the basement toilet relies on this stack for venting.

Here is a closer look around the 3" vent to roof for your reference:
http://picasaweb.google.com/abrahuang/HouseBasementPlumbing/photo#5119214941960730114

A vent can run horizontal, it should have slope to it so any condensation or rain water can drain, but once you dump a drain into it from that point down, it is a drain, not a vent. Now, that doesn't mean it can't perform the function, but it means that it might not all the time; depends on what is being drained at the time. Codes like it so it will work all the time; at least under normal circumstances.