Hi all, thanks in advance for any help you can provide. Here's my situation:

I'm redoing the drain plumbing for my sink and washer drain in the garage. I'm doing so because I'm moving both down the wall 2-3 feet. The clothes washer also used to drain into the garage sink, and I'm adding a fixture box (correct term?) for the valves and drain.

The wall that this plumbing is in has been furred out with a second 2x4 for a few reasons, one of which was adding room to make plumbing easier. Currently, a 2" CI wye protrudes from the slab (at the house level, garage slab is lower, see pic) with a cleanout in the y side. Coming out of this is a 1.5" san-tee pointed out of the wall. I'm planning on removing this tee and replacing it with abs using a hub donut into the cleanout wye (the reason for the 45 is to bring it out of the structural 2x4s and into the furred 2x4s so that I can cut holes at liberty). I would prefer not to mess with the wye since it's buried in the slab, but the real problem is that I'm worried about getting enough height/length on the washer standpipe above the trap. As I've drawn it, I can get right about the 18" required height, but I've read that more is generally better, and that sometimes 18" isn't enough.

The second question I have is whether the sink stub can be at the same height as the horizontal run (aside from the 1/4" slope) as in the second picture. Thinking about it I can't see why it would really be a problem, but I don't have years of experience in this area, so I'm asking. If it's a bad idea, I am pretty sure that I can bring it up slightly using two 45s as shown in the first picture, the limitation being that the stub obviously has to come out of the wall below the sink, not into the back of it.

The last question is the vent size, it currently has a 1.5" vent going up through the roof (since it necked to 1.5" drain for just the sink). Do I need to replace that with a 2" vent. Air is a lot less viscous than water, and it seems like it'd be fine, but again, I'd rather ask and be wrong, than do it without asking and find out I was wrong later when I have a problem! :eek: (It's just a vent, nothing else above it)

Also, it may not be clear in the pictures, but I was planning on keeping the original vertical vent going all of the way up, i.e. keeping the san-tee that I'm replacing tied into the san-tee that I'm using to tap back into the vent line. If I'm way off base and my plan is entirely fubar, please let me know that as well. :D I can think of a couple of possibilities if so, one of which being to break out the edge of the slab and replace that cleanout wye, but I'd much prefer this way if it will work.

Sorry for the long post, but I tried to explain it as well as possible, if there's anything unclear, please let me know.

Thanks a bunch!
-Kris

One other quick question, assuming that the rest of what I've got there will work, can the vent Tee in the bottom right of the diagram be a san-tee on it's back? I know that you can't do that if it's draining anything, and I also know that it's fine for purely vent pipes (like the vent tee for the washer), but am unclear on if it's acceptable in this case, since the fitting does drain, but the tee'd part is only for the vent.

Thanks,
-Kris

Anybody have any thoughts on this?

Thanks,
-Kris

Hi Kris...

As far as I can see you have this drawn up perfectly.

How are you planning to pull that fitting out of the wye fitting to install the fernco donut you mentioned? You could use a 3/8" drill bit (or smaller) and drill down through the 1-1.5" deep lead and then try to wiggle the ftting and remove it, but be aware that there is some OAKUM in there that will fight you a bit so plan on wiggling quite a bit to get the fitting out. Otherwise, you could also use a bimetal sawzall blade and sawzall to cut the fitting aboout 1.5" above the wye fitting with cleanout and then install a SHIELDED CLAMP (see image) to transition over to the ABS plastic.

In terms of your piping diagram I don't see any issues and as long as you have the 18" minimum standpipe to the washing machine box I'm confident that you will be fine, but don't be afraid to raise the washing machine box a couple inches higher if you are concerned... washer pump can handle the increase in height no problem! In my state we install all washing machine standpipes between 18-30" and never have issues unless the drain line is clogged or partially clogged...OK?

You should also be able to pipe up straight over to the sink as long as you have the 1/4" slope... no need to offset up, but do check to be sure that the 18" height you have doesn't run into the back of the sink... just to be 100% sure.

In terms of the sanitary tee fitting for the sink vent... that is fine because it is for the vent as you mentioned. Be sure to install a wye and 45 fittings to pick up the washing machine drain.

Only other thing I wanted to touch on was that the fitting for the vent needs to be inverted so that rain water that comes down the vent will drain back through the pipes via gravity. This just means that the sanitary tee fitting for the vent must be placed into the vertical piping upside down and that the other sanitary tee fitting on the horizontal vent needs to be placed backwards.

Finally, I like to install a 2" cleanout (called a dandy cleanout or a test tee fitting... see image) in the drain line... you could also install the cleanout in the washing machine vent.

Back to you if you have any more questions...

MARK

Mark, thanks for the reply!

That's exactly the method I was planning on using--a drill and some time prising at the lead and oakum until I can get it loose. I had thought about using a band clamp as you pictured, but would like to avoid it in order to keep the whole assembly as low as possible.

Good to hear on the standpipe length. Is there a standard height from the floor for the end of the standpipe? I know that it should be at least 2 inches above the spillover of the washer, but I don't recall seeing much else in regard to an acceptable height range. I suppose the height I was planning on putting it at was determined to put the valves at the same height as the old ones, which seemed like they were at the "normal" height.

I'm glad to hear that the sink doesn't need to be offset up. I couldn't think of a reason why it would matter, but again, I'm not the expert! Without the vertical jog I'm sure it will fit under the sink, as it will be at the same height as the old one, and I'm using the same sink.

It certainly seemed to me like the regular tee would be fine to tie in the sink drain. Good to know on the vent fitting orientation as well--it doesn't seem like it would be a huge issue if they weren't installed correctly, but does seem like a good practice.

Where would you add the cleanout? The washer vent? The only place I could see that being helpful is if there's a clog between the san-tee after the washer trap and the horizontal line, otherwise you could snake through the sink stub (some work to remove the trap, but it's a hanging wall sink so it's accessible).

Lastly, I'm pretty sure that I can also use a combo-wye for the washer drain tie-in, rather than the wye+45 method. What I haven't seen discussed is if one or the other of these methods is preferred.

I'm glad to know that I've got a decent handle on this stuff at this point. Thanks again for all of your help!

-Kris

Kris...

Standard height is about 43" off the floor...if I remember correctly, but more important is that minimum 18" washing machine standpipe. As long as you have that you should be fine.

It wouldn't be a big deal on the orientation of the fittings for the vents, but it would be wrong is all. Now that you know for sure, just as easy to do it right and then knowone, not even an inspector could mess with you.

In terms of the cleanout... OK at horizontal washer line as you could snake in both directions toward the drain or toward the sink. Also OK at the washer vent as this allows the drain and sink to be clogged but you can still remove the cleanout cover without having to worry about draining and catching all the water... and then snake. Only drawback with the cleanout in the vent, as you noted, is that the cleanout will not help with a clog between the sink and the washing machine. If you install a UNION TYPE PTRAP at the sink and a 2" cleanout in the washer drain or vent you willl have all bases covered. The union trap simply unscrews and rotates out of the way so you can snake the drain through the full size union connection.

The combo wye or the wye and 45 are basically the same thing... just less joints to cement... ;) Use either... I just didn't want you using a sanitary tee fitting on its back!

Let me know how you make out... OK?

MARK

Great! I definitely agree on the fittings, even if from a practical standpoint it's trivial, I'd rather do it the right way.

That's what I was thinking for the cleanout--to put it in the vent and use a union p-trap to keep that option open. Between that and the existing cleanout in the wye, there should be plenty of access if I ever get a clog. And I will definitely not be using a san-tee on it's back for the washer, only the vent.

I'm hoping to get this done over the weekend, I'll definitely take a picture when it's complete and post it up!

Thanks again!
-Kris

BTW, the "Rate This Answer!" button only shows up for my own replies, not yours. What am I missing?

Just curious.. Do you see a SCALE at the upper right corner of my posts? If so, click on the scale... that would work. If not, let me know.. OK? Thank you.

Nope, no scale either. Could it be because I'm a brand new member? Seems odd that the RTA button shows up for my own posts though (but no scale on mine either).

No... something else up here. Not just happening with you.. ;) Thank you for taking time to reply!

Look forward to your pics!

MARK

Mark,

Here's a picture of the almost finished product. It's all just mocked up right now, not glued yet, but at 11 o'clock last night, I was ready for bed. I worked on a lot of projects this weekend, not just this. :) I probably spent 4 or 5 hours on this one, at least two of those digging the lead/oakum out of that joint in *slightly* cramped quarters. In retrospect, I definitely should have tackled this project before drywalling the other side of the wall!

You might notice a slight gap in the washer vent; I still need to put the cleanout in that one. :D

I'd say that all in all it came out pretty close to my plan, and I ended up with about 21.5" of height on the stand pipe, with the box at 44". Perfect!

Thanks again for your advice!
-Kris

Great job!

And without damaging the sheetrock... WOW!

I'm not sure I could have done any better there... I swear!

Thanks for posting the pics. Pop back anytime... OK?

MARK

I just wanted to say thanks again. I finally got a chance to finish this project up. I learned quite a bit doing it, and it's quite a satisfying feeling to know that it's done properly. Attached is one final picture of the finished product.

So, thanks again!
-Kris

Hey! We're all glad to help here... :) Thank you for taking your time to post a follow up. Really looks very good you know!

MARK