Second floor plumbing plans and pics....please help.

Ok....so I decided to take on this huge task of finishing the upstairs myself in order to afford to even do it instead of taking 20 years for someone to do it for me. I am a novice at all trades but not a master to one....so please bear with me.

I have a lonely toilet in the basement which I believe has a two inch vent line to the roof. Next to that 2inch vent is a 3 inch cast iron going to the second floor and was to be used at a later date. This house was built in the 1930's and the second floor was never touched...not even framed. Just an open room so it is like new construction for me. Here is the rough sketch. The bottom view is looking down from the ceiling and the top view is the side view. I am trying to figure out how to upload these pics I have so bear with me.

My biggest question is can I have two toilets, two showers, 3 sinks, and a laundry going down one waste line but I will have a 3 inch vent and a 2 inch vent going to the roof?

This pic shows the floor...2inch for basement toilet vent...3 inch for upstairs plumbing.View attachment 13354

This pic is in basement before branching out for upstairs.


On the main floor there was a coat closet conveniently where I was putting the plumbing so my wife liked that there was no major construction in our living space. I did put cleanouts for each 3 in on the main floor for your reference.


This is the meat of the project....as you can see there is a 3 inch waste on the left with a 1 1/2in tee for one of the double bowl sinks and farther up there is a 2 in still available for the venting of the shower, toilet, and the other sink of the double bowl. The third pipe (3inch) on the right branches toward the pic and will be the waste for the other sink, toilet, and shower. The 2 inch tee off of that same pipe will serve the laundry.


This pic is on the other end for the master bath...like I said I am a novice so I think I might of done the water closet(toilet) incorrectly so let me know but the vertical pipe is the toilet(right side of pic). The other smaller upright stub will go in the 2x6 wall to serve as the sink drain and to continue up for venting sink and toilet(can I do this???). The third stub will continue down floor joist and then have a trap for shower and I will branch off of that to have a vent that I was planning on tying back to the sink and toilet vent before going into roof...or do I need to just make 2 roof openings for each vent...it is slate roof so I was wanting to minimize dollar control because I am hiring that out.


Please let me know if I am way off or if you could please steer me in the right direction...thanks.

It is very difficult to correlate your description to the pictures, but one error seems to be that the "vent" for the one sink is NOT 42" minimum above the floor. You tub vent on the left side appears to be horizontal, which is not permitted, and why are you using 3x3x3 Ys with reducers instead of 3x3x2 Ys? It is NOT an "improvement" even though it would logically seem to be one.

You got me on the 3x3x3 Ys....The department store was out of them so I bought a 2 in bushing to make it 3x3x2 Y's. So it is not permitted to run any vents horizontal to tie in to another vent.....can I just run it at an angle until they meet? I guess I can run them into the roof rafters to the back end of the roof so not to put eye soar of more vents in the front of the house. At what angle can I run legally for venting?

Here are some pics to clarify your questions.

As you can see the vents are tied in above 42 inches.


Are you referring to the description vent 1 from the laundry waste not being 42in before tying into vent 2?


Is this what you are saying HJ about horizontal venting?

I think I am catching on....so if my 2in drain vent needs to be vertical what kind of connection can i make while it is running down in between the joist? Just before entering the shower I can run a vent pipe in the shower wall vertically. I don't have 2 inch fittings at the moment but pretend that this pic represents 2 "...can I use a tee or a wye to go vertical in the wall? (assuming a 2 in wye will work in a 2x4..I can make it 2x6 to make it work)

CORRECTION...the wye needs to be faced the other way...single opening towards waste and the double opening towards trap...correct??



Is my toilet vented properly in the pics above?

So after reviewing some other things I am finding that using a tee as a vent in a horizontal drain is a big no no...in other words can't lay it on its side. Can I use a wye and tilt it at an angle with the double end pointing towards the p trap of shower and say the angle is at a 45 until I can get it to go vertical in a wall up to 42" and then horizontal to the main vent? My last question is when I wye before a toilet closet...say 6 inches before and that wye proceeds to go vertical into a wet vent fashion with a 1 1/2" tee on it which will serve a sink will that vent be proper for the venting of the toilet? The vent will go straight up the wall into the attic and will tie back into another vent before leaving into the roof. All vents I have mentioned will be 2".

Please review all of my pics and let me know if I am doing something that needs to be changed....ready to proceed.