DWV Design Questions/Review

Ugly drawing attached. Black line is just a break in the drawing. It's not all inclusive. Assume 1/4"/foot slope for all horizontal runs. Vertical pipe in front of washer drain is the vent for it.



Looking for guidance on type of fittings mostly.

1. Where sink drain joins Tub drain line, what kind of fitting should I use? (San T, Wye, etc)
2. I'm assuming a normal Drain (Not vent) elbow is fine here?
3. Fitting type needed?
4. Can I vent like this, or does the vent need to come off of the trap arm before the vertical drop? What fitting is needed here?


First point: I have a 1.5" Washer standpipe now. My W/D is a stacked single unit only 24" wide, and we will only be making enough space in the kitchen between cabinets for a 27" wide unit. So the machine will always be a small unit, and thus not have huge amounts of water coming out. The 1.5" has been working fine for us even though the rest of the drain line currently is not ideal. (There is a low spot and a Fernco in the branch) And it IS legal in WI to have a 1 1/2" line on clothes washer.



So, with the correct fittings, what's wrong with this setup? Recommended cleanout locations? Thanks for your time and effort in advance!

drain

I would not use less than 2" for any drain, and 1 1/2" for the vents. Where do you find 1 1/4" pipe and fittings for drains and vents? Just because the code ALLOWS a 1 1/2" drain, does not make it a good idea. The code is a minimum requirement, but that does not make it adequate in every case. The general rule is to use combination Y-1/8 bends in horizontal lines and sanitary tees in vertical ones.

HJ, I hadn't really looked for 1 1/4" pipe and fittings, so I may find they are unavailable. But, what's the problem with a 1 1/4" vent? A 1 1/4" vent in my state can serve 4 DFUs at a 40 foot max developed vent length. I want to vent 3 DFUs at a vent length of about 15 feet. I guess I don't see a problem with that. Where's the potential harm?

And a 2" drain minimum? So you would have a 2" drain right after the trap weir on the bathroom sink? Why go so large? Would you do so to avoid clogs?

Is this the combo Wye/ 1/8 bend? Just making sure I'm picturing the correct fitting.

Still looking for recommendations/suggestions, especially on where to locate cleanouts.

Nate R said:

Is this the combo Wye/ 1/8 bend? Just making sure I'm picturing the correct fitting.

Click to expand...

Yep!

Lengthened to longer than 10 characters because that makes no sense...