I am rehabbing an old apt building and installing 3 new laundry rooms. Could someone please explain to me and/or draw a brief sketch of how to plumb up the waste and vent lines from the basement to the roof. All three machines will be directly above each other. A sketch of how to run the pipes would be very helpful. :confused:

Is it just washers? Lowest washer start with a 2" vent line up through floor and past the second washer. start the second washer vent and 2"and run up beside the 1st floor vent. Now for real good venting take those two vents and tie them onto a new 3" vent and run that through the top floor. run that past th 3 washer and hear pick your third 2" washer vent and tie that into the 3" pipe.Then go through the roof and above the roof 24" Drainage is a 2" piece (stand pipe ) 28" min form the washer outlet to the botom of that pipe which needs a U bend to trap sewer gas. From there go to sewer line with proper fall 1/4" min per ft. Now here's the real codes. The washer needs a washer pan underneath the washer in case the washer overflows and the tennat down below won't get wet These pans are hooked up to the sewer line but there traps dry out and dah! Sewer gas. The other bigge is by code your vent line has to be black iron no hub. And couplings. The reason for this is P.V.C. pentration through another floor is considered a fire chase. Ergo steel won't melt and allow the fire to get into the next floor. Which is expensive but it is a good logical reason

You are not stating under what Plumbing Code you will operate. But, there are 2 basic ways how to proceed. One is more complicated (UPC Code) and the other one is more straight forward installation.

I am including 2 drawings. They are not up to scale.

First one is by UPC. All vertical drains are 2" so are the vents, traps and 30-36" stand pipes. The main horizontal pipe is at least 3".

( There is also an option of combining each floor with the floor below. It is more complicated and may be confusing to you at this time. Let me know if you are interested in this option as well )

In the Second drawing, the main vertical stack is at least 3" common drain / vent that runs from the bottom all the way to the roof. You connect each laundry with 2" pipes, traps and 30-36" stand pipe.

Check with your local Building Department to see what layout will pass inspection. The only one that would pass in my area is the upper drawing. Good luck, Tom

I would stick to the first drawing also, great advice milo.

[Thanks for the reply, but I'm still confused on how to get all those pipes past each other inside a 2x4 wall? QUOTE] Fur out the wall to accommodate the pipes.
[QUOTE]Can I run a 1-1/2 single vent off to the side and tie into it 6" above each washer as I go along./ As I understand your description you would still be using a common drain line just like in the lower drawing. Go with the upper drawing. Good luck, Tom

Move drains to where they will not cross over. The first drawing is just an example. You should be able to reduce to 1 1/2 vents for each drain. Just size up above highest washer. I don't know how to give a drawing. Hopefully Tom or Milo can give more options (with a drawing) that will have the same effect as the first drawing.