[DIYHero]

I have a 4 unit building, and am interested in installing a drain pipe for a laundry in each unit.

The building is arranged 2x2 (2 on top 2 on bottom), with identical/mirrored layouts.

I would like to have the top two units each have a 2 inch pipe, which drains into a 3 inch pipe to run down to the first floor, where it will turn into a 4 inch pipe where two more 2" pipes (first floor) laundries tie in.

The 4 inch pipe would tee into the main waste line, also a 4 inch pipe.

I chatted with a guy at m local plumbing suppl store, he said each laundry drain has to "home run" into the main waste line to be up to code. Sounded like overkill, considering we have buildings with hundreds of units in the city and I doubt every one of them have a 2 inch drain pipe running down to the main sewer.

Is this correct? Also, if my original plan is acceptable, what size should the pipes be as more waste water is fed into them?

i tried drawing a picture in ms paint, but everything came out stupid looking.

 

[oh'mike]

Give us the location of the building for code reference---that does not sound like any code requirement that I ever heard of-----

 

[DIYHero]

Washington, DC.

ill update my profile

 

[oh'mike]

Thanks----I'll wait until a licensed plumber catches this---I know a lot--but this answer better come from someone with proper code knowledge----

 

[TarheelTerp]

I chatted with a guy at my local plumbing supply store, he said each laundry drain has to "home run" into the main waste line to be up to code. Sounded like overkill, considering we have (much older) buildings with...

It makes sense on a lot of levels.

The standard isn't what can we get a way with...
it's what problems can we anticipate and do something to prevent.

Either way... how much trouble would it be to run the second 2" pipe
through the first apartment and to the upstairs unit? Then you have two 2" connections at the 4" instead of one 3". BFD?
The ground work is still the beotch.

 

[TheEplumber]

The big issue with modern codes is "suds relief" and each code addresses it differently.
You're design would be close to working in my area only because you're less then a 3 story structure. However, DC maybe totally different- best to call the permit people and get a straight answer

 

[DIYHero]

Thanks for the responses.

I never work towards what i can "get away with"

It wouldnt be too difficult to run two 2" pipes from the top.

Where I am getting incredulous is Teeing four different two inch pipes into one 4" waste line. With that setup, about 2 feet of the line would be comprised of one Tee after another, requiring a lot of room for the pipes themselves.

Thankfully, im working with a dirt crawl space and teeing into the main line itself will be a breeze (famous last words).

 

[TheEplumber]

Thanks for the responses.

I never work towards what i can "get away with"

It wouldnt be too difficult to run two 2" pipes from the top.

Where I am getting incredulous is Teeing four different two inch pipes into one 4" waste line. With that setup, about 2 feet of the line would be comprised of one Tee after another, requiring a lot of room for the pipes themselves.

Thankfully, im working with a dirt crawl space and teeing into the main line itself will be a breeze (famous last words).

Don't forget the fixture vents- more pipes :whistling2:

 

[DIYHero]

I was planning to use a proflow attachment, which is code in dc thank goodness