In our 2nd floor NY home we're finally finishing an attic room. Room has a 3" copper vent line smack dab in the middle of the room, so we're going to hide it inside the floor and knee wall. Floor joists run the correct way for us to get the 5' run to behind a knee wall.

Here's a sketch. Left is as is (vent from below floor to above roof), right shows how I'll add this: cut the existing vent 2 places, connect to 3" PVC with flexible PVC elbows. I'm adding the top two 45 so I can get a simple connection to existing roof vent. (These 45's may be changed to flex couplings depending on how close my roof is to a true 45, I have yet to test-fit anything.)

Also going to add a drain to the clothes washer up there (best not to ask how it currently drains) via a 3" line (the new 2009 code I read here today) with P trap. This line actually runs into the paper but shows sticking out what is really outside of the house for clarity.

All pipe is 3" PVC. All horizontal runs will have proper slope (1/4 per foot).

Does this look like a plan?

The overall idea of moving the vent can be done, but I'm afraid I see a few things that at least raise questions that need to be answered before I can tell you the best answer.

That 3" vent stack is a vent stack for something... that means that it can't serve as a waste line for the washing machine. If you connect WM into this vent stack and it serves fixtures below you can be sure that you will be siphoning the traps from fixtures dry and the toilet will bubble/gurgle and cause odor issues (allowing sewer gas into the home).

In terms of the 2009 3" pipe requirement for washing machines, I have yet to see it in writing as being required anywhere... I have heard RUMOR of it, but I have yet to hear anything more than rumor, so stick with 2" pipe...I promise it will work perfectly!

That being said, I would run a 2" waste pipe from the washing machine to the bathroom downstairs, and connect into the waste lines BELOW the vents from the bathroom (in the waste lines of bathroom). You would run a vent after the trap for the washing machine in the attic and connect the VENT for the washing machine into the 3" vent stack that you are moving...that make sense (see picture below)??

I have not seen 3" flexible PVC fittings... do you mean flexible RUBBER elbows? If so, these are illegal for what you are doing. I would prefer to see you purchase a 3" copper x 3" plastic shielded clamp (see picture of clamp) to transition over to PVC plastic pipe and then pipe all this solid PVC then to have those flex type fittings. The flex fittings/clamps do not joint well to copper.

You will also need to consider a washing machine pan and either a way to drain the pan outside or to the drain pipe (needs trap/vent and a trap-primer... complicated) or at least install an automatic shutoff device at the washing machine (see picture.. called floodstops). Here, the auto. Shutoff attaches to the water feeds for washing machine and then a SENSOR is laid down in the washing machine pan. If the sensor senses water it shuts flow of water automatically. It is not fool proof... but it is better than no auto. Shutoff system in place on the 2nd floor... in my opinion...

Let me know more here.

MARK

Thank you Mark, all points well taken. The 'rubber' flex joints looked to me like a perfect solution to getting the bends and the dissimilar materials joined with one fitting but I bow to your experience.

(Funny, I posted from work as I was leaving and it only hit me on the ride home that I was putting waste down the vent. I had been thinking of this for over a week before that light went off. Good catch, thanks again.)

So keep the vent just a vent, replace flex elbows with 90 degree PVC and use shielded clamps to connect PVC to copper. Check. Add a 1 1/2 vent from washer drain. That much looks solid.

The additional 2" drain line needs to tap in the first floor. Down on ground floor is an existing "thing" (I don't know the correct term), a 3-4" pipe coming up the floor that the downstairs dish washer hooks into , the hose just hooks into the opening. (The upstairs washer also hooks into here which is why I'm looking to change that). I found a picture of this arrangement someone had posted (see below, from another house in my development) where this pipe is used for additional drainage.

I'll use another shielded clamp to tie in the 2" line solid, plus a couple of 45's so I can wiggle around the existing vent stack. I believe this drain to have a P trap as I never had any odor issues from it (and the top is wide open), and it never overflowed from anything put into it.

I'll use a DW downspout on the sink to drain the DW as I've lost my easy hook shot.

Does this look like a plan for the drain?

Hi Ernie...

You said, " I believe this drain to have a P trap as I never had any odor issues from it (and the top is wide open), and it never overflowed from anything put into it." You aren't planning onto tying onto the drain with the ptrap are you?

You want to cut a 2"wye fitting into the drain line above (ADD A CLEANOUT after the wye fitting) and go from there... or did I misunderstand?

Let me know...

Hello Mark,

Sorry... in the picture the pipe on the right is my existing sink drain and vent. That will be cut one floor up and used just as a vent, the part in the pic is not to change.

The pipe shown on the left In my house is just an open pipe, no fittings, just an open pipe above the dashed line. The existing dishwasher and clothes washers both hook into the top. I plan to use this to make a closed tight connection for the new 2" washer drain line.

I don't need to cut into this line as it is already open, I'm going to close it in with the 2" line coming down. (Do I need a clean out there?)

Revised picture (photoshopped in Microsoft Paint):

Ernie... shine a flashlight down into the drain pipe. Is there standing water? If so, plumbing code doesn't allow for double trapping of a fixture which is what you would be doing to the washing machine if a trap is present underground there...

I am afraid that plumbing code would tell you to cut into that pipe on the right... and yes, you would add a cleanout just after the pipe headed toward the washing machine drain.

Let me know what you find...

PS: Measure the pipe diameter will you...looks like 3" from here.

MARK

I use these for vents whenever possible.

STUDOR® | IPS Corporation

Mark,

OK, so I need to use the existing waste line for waste (duh for me). I assume I need to make the inlet for the DW drain below the sink (or sinks, that is a T connection, bath sink is behind kitchen sink). This means I have a height constraint getting two separate fittings (2" DW drain Y AND the cleanout) between the sink T and the slab concrete floor. That isn't a problem if I can combine the 3" Y and the cleanout.

How I see to do this is cut the 3" copper (I measured, and the OD is just over 3") below the existing T and remove it for most of it's run. The build-up from bottom up will be:

Shielded clamp from copper to 3" PVC;

3x3x3x3 double Y, one end for new 2" drain, other end for 3" cleanout cap;

3x3x1.5x1.5 double sanitary T to drain both sinks;

3" PVC going up and angling around till it gets a shielded clamp to vent just below roof;

2" PVC waste line up and around as you indicated (with venting);



I'm hoping that will cover the cleanout requirement.

BTW, should I add a cleanout in the 2" horizontal run where shown? That end will have some access and it can't hurt to have a extra cleanout.

Thanks again for saving me from disaster!

Ernie...

I need to know if there was a ptrap on that pipe the dishwasher and washer connected into (left pipe in pic.)...

Where did the 2 sinks come from? Or are we discussing the right pipe in the pic.

Let me know this stuff then I'll go back and review the info. You posted.. ok?

Thanks...

MARK

Quote:

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Originally Posted by massplumber2008

I need to know if there was a ptrap on that pipe the dishwasher and washer connected into (left pipe in pic.)...

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I believe it to be p trapped down inside the slab as it has been open for 60 years and does not smell, gurgle, etc. I can give it the blow-in-a-tube bubble test is you really need to know but I no longer intend to use is since you pointed out it would be a double trap situation. (I will probably cap the left side off at the end of this work.)

Quote:

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Originally Posted by massplumber2008

Where did the 2 sinks come from? Or are we discussing the right pipe in the pic.?

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Yes, I now plan to add the new DW drain to the pipe on the right. This drain has two sinks connected to it, that is how the house was built. (BTW it's a Levitt Cape if you've ever seen one).

In the pic of a similar house you can see an open drain pointing at you, that is for the existing kitchen sink; the drain on same right side pipe going to the right then angling away is the existing bathroom, in my house the bathroom sink is directly behind the kitchen sink so this drain would connect to the other side of a sanitary tee.

So those are where the two sinks came from. I trust that since the as-built & existing sinks are trapped the right side drain is NOT trapped and can work for the DW.

Actually checking for a p trap in the right side drain before I begin this isn't very do-able, as the work is very old school and solid metal from the basin connector through to the vertical drain (so I probably would not hear a blow-in-a-tube bubble test even if I had any confidence that the tube snaked down to a trap area).

Thanks Mark!

OK...

Now I am wondering about the dishwasher connection..?

We started talking about adding a washing machine in the 2nd floor...

Where did that DW come from? Is this the same dishwasher that was connected to the pipe on the left (open pipe)? If so, just leave it connected to the left pipe as it is. If not, explain... ok?

Otherwise, everything else looked dead on!

Let me know a little more...

MARK

Ugh... sorry Mark, I'm going brain dead here. It's not a DW, the addition is (and always has been) the clothes washer we have on the 2nd floor. The first floor dish washer has and will remain hooked into the left pipe.

As I get older the bone in my head that selects proper nouns is getting smaller and smaller.

I sure do appreciate your help and guidance here. (And your patients with an amateur).

Then everything looks good.. :)