Lot of questions...

Hello, I am new here and need some plumbing info.

I am in the process of replacing a bath/laundry in the garage. The old one was done w/o permit so I ripped it out, got a permit and building new. Everything has been going smooth till the plumbing.

I just can't understand plumbing.

The questions I have relate to DWV and the fittings needed. The area has joists ledgerd above slab with 9.5" from slab to top of joists. I am confused about the horizontal pipe runs. How do I go from 3" pipe to 2" (for shower, washer, sink,) and do it to code and in the space allowed? What fittings are needed and what angles do they have to be at?

My plumbing books didn't tell me a 'santee' is a no-no laid flat. How do I get by this? I have a pic of the area here; Thanks!

The plumbing in the pic is from the old bath... and is going away.

I applaud your attempt.

I would suggest that if you don't want to be riping out work you have done and don't want to spend a lot of time and $$$ spinning your wheels that you hire a plumber. He has the knowledge and equipment for testing and will be able to do the job quickly.

You have not given us enough info to tell you what you need to do.

There are couplings and or bushings that will reduce 3" to 2".

The pic is way to small.

drain

Every plumber might design the piping differently, but we would have to be there to see the entire situation. I am afraid, given the question you are asking, that doing this yourself is a road to disaster, or alternately a very, very lengthy process. You have a good picture of the 2x6 walls, but they are in the way of what we might want to see. As far as the piping is concerned, it is like asking us how you like your new car, but showing us a picture of your old one.

draw it on paper

hi dude man

try again, by drawing out a first attempt using a stick drawing in naive fashion. I use MS Paint to make a monochrome bitmap, and each drawing is about 20k in size.

That will give people something to bite into. So far your question is too general. It'll be easy to help you when you give more info. I'm sure you'll be happier when you get a drawing done.

The picture is less than ONE square inch. Try again.

david

First, determine how far it is from the toilet to where the drain goes into the slab. The code above requires 1/4" per ft of drop for the horizontal runs of 2" and less, and 1/8" per ft for 3" and larger. Your code may differ.

Lay out starting with a "closet bend" for the toilet and see if you can get to the drain with the proper slope (your code) and put in a vent. If you can do that, then you can probably get the other stuff in without breaking concrete. Then figure out how you are going to connect the other stuff, including the vents.

Since you have joists over slab, you can probably notch and support joists on slab as necessary where you have to cut joists.

Hello all, Thank you so much for the replies.

I am sorry for the confusion.. You may have to double click the thumbnail pic I posted above. (double click on the 1" square pic)

I have a drawing I will post and take more pictures. I would like to do this project myself. Right now I am unemployed, funds are short and it's a chance to learn something new.

More Info

Problem # 1. I need a 2" wye from 3" pipe for the shower. From what I understand, the wye needs to be at 45 deg and have an extra fitting as well ( to be above flood plane). What is this fitting?

Problem #2. I was going to vent the toilet with a santee with 2" verticle. They say I can't. I need a long sweep with some other fitting. This would go in the 2x6 wall, What is this other fitting?.

At the toilet, the 3" pipe will be 1" below top of joist. will this work? The floor will be 1.5" thick.

I have added a drawing in the link below. You need to double click the pic.

Thanks

From the limited info here is something I came up with...
May not be what you intend though...
Note:
1st set of pipes reduces from 3 to 2" above slab - I have not gotten around to drawing test-tees in 3d CAD yet so imagine a cleanout where the pipe changes size (LOL). Use 3" combo for vent and 3" sweep or closet bend for WC.
Second riser is for lav not shown on your drawing. 2" combo lying on back for riwser with a 2X1-1/2" san tee for lav.
3rd riser is for washer box - remember to place trap in wall below washer box. 2" combo on back for riser with 2" san tee leading to 2" p-trap for washer box.
4th riser is for shower - san tee is below floor and trap must be 2" min.San tee is above the 2" sweep.
Remember to place an end of line cleanout above the floor on the shower vent - usually facing the back side of the wall....
Note that the 2" lateral and the 3" WC waste join with a 3X2" wye and 45... This is the best I can do with the info provided...
Vents can be joined at any point at least 6" above the flood rim of the highest fixture (usually the lav or washer box...)
Any comments or criticism, feel free...

Edited layout due to changed info...
Here is another go - should be self explanatory though...

Markts30!!!!

Thank you! The drawing you have provided is what I invision.

I just don't know what the fittings are called. What is the XYZ (in your drawing called at the store) also they told me a 2" vent for WC is OK, so it would be 2" not 3" (I think).

3X2" wye and 45 Is this 2 parts? and at what angles? are they the fitting names?

San tee is above the 2" sweep Is the "sweep" the p-trap or the pipe below santee?

Thank you Mark. A trully sincere THANK YOU.

A: 3x3x2 combo - combination wye and 1/8 bend
B: long sweep 1/4 bend. (90º bend that has large radius)
Different locations may call some fittings different names

drain

In your situation, you should not have enough height for a sweep and tee for the shower. You should use a 2" combination Y-1/8 bend on its back with the branch going vertical for the vent, (the garage sink would be connected to it using a sanitary tee at the proper height), and then a long radius elbow into the end of the combo turning to the shower trap.

Revised plan as I understand the change...

Thank you HJ!


"You should use a 2" combination Y-1/8 bend on its back"

A stupid question - The store has 2 types of 1/8 bends;

1) 1/8 bend with flanges on both ends for pipe fitting.
2) 1/8 bend with flange on one end and flat on the other end so it can go directly into the Y.

Can I use #2? they call it a 2" 45 deg street elbow

There is a single fitting called a combination wye and 1/8 bend. It is easier than gluing together your own.

plan

REvise the drawing one more time. Roll the combo going to the shower trap vertical for a vent and put the sink tee into it. Then roll the far right vent horizontal to become a drain and put the trap on it. A combo is a single fitting, not two glued together although you can do that to make your own combo.

Try this.....