If you have a 1" port available, you can use it, but you'll have to reduce to 3/4 at the heater. It's a good use for a 1" port.

Eventually the manifold will run the whole house. I probably won't repipe the whole thing quite yet.

In that case, what do I need to do with regards to the hot water heater? Can I repipe it to be 1"?

Mark-

Long time no talk, hope you're doing well. Thanks again for all the help.

Got a couple more questions for you.

1) How can I figure out for sure if my current water main is 1" or 3/4". I am pretty confident it is 1", but would hate to buy materials and run the lines only to be wrong.

2) You were right, my water heater is only 3/4", do they make 1" water heaters, or is there anyway to increase the water heater supply/output to 1"?

3) The design of the bathrooms puts some plumbing on exterior walls. In these instances, am I better off running the water lines up through the floor as opposed to in the wall? That is to say bring the water line for the toilet up out of the floor, same for the vanities, to keep it in conditioned space? We get some freezing weather here in DC.

No 1" tappings on normal size residential water heaters so I would pipe 3/4" into and 3/4" out and run all from there....You won't be running that many fixtures at the same time that I would worry about this. Otherwise, you could run 1" pipes in and out, just not sure it's worth the money... however I see it done once inawhile.

Bring the pipes up through the floor... no question on that. Easy to do and never have to worry.

Circumference of 3/4" copper tubing is about 2-5/8"... 1" copper tubing is about 3.5" circumference... so that should help you determine size.

Keep 'em coming as needed.

Excellent. Running the pipes through the floor won't be an issue at all, really. Thanks so much, I am guessing this saved me a fair amount of grief. Any issues with DWV pipes in exterior walls? Guessing no, but just to make sure.

No issue with PVC pipes in wall. I am sure you already know that no washing machine ptraps should be in any outside walls... just to be clear on issue!

Because of the standing water, right? I think the only PVC in an exterior wall will be a horizontal run for the 2nd story lav.

Correct... because of the standing water... ;)

The lavatory pipe will be fine as long as it is pitched to 1/4" per foot. I end up with lavs. And kitchen drains in outside walls all the time... so you will be fine here!

Hey Mark. Hope you're well. I am hoping you'll see this. I finally have a schematic drawing from my architect. Plans have changed a little bit since we last talked and as such, I'd really appreciate it if you can help me figure out this new setup. The big change is that we're no longer including a full bath in the upper portion of the addition (we'll be adding a full bath on the upper level, but if doesn't factor into this setup).

Does this change much of anything? I figure I will be able to penetrate the roof with a 2" vent, instead of a 3", correct, or should I go up to 3" anyway?

Any thoughts? Concerns? Suggestions?


Mark-

Thanks for all your help. We're finally getting close on this project. We've got really drawings and everything. I'm hoping you can take a peak at this and give me your opinion on how best to plumb the half bath and the washer. As I mentioned, we can wet vent here. I've shown the only real option for the drain pipe to connect to the main stack. I know it isn't optimal, but will it work? How do I go about tying in the washer?

Any concerns? Thoughts?

Thanks!

Hi Stubits!

Here is a quick draw up of how I would pipe this. The toilet gets wet vented by the 2" lavatory waste/vent. The washing machine and the kitchen sink each get their own 2" waste line and 1.5" vents. The kitchen sink requires a 2" cleanout under the sink... so remember that when hooking up the sink. I also like to install a cleanout in the washing machine vent, but it is not required.

All vents connect at convenient spot upstairs and penetrate the roof 2".

Let me know if you have questions...

MARK

This is great. Many, many thanks!

As always, I've got a couple of questions.

First, the kitchen sink is already in place and plumbed, so it's not a component of this project.

Second, I guess we've managed to reduce the number of cleanouts from earlier plans by using more 45's, right? On the topic of clean outs, how far should the cleanout be from where the two pipes intersect?

My goal is to run the 3" pipe through the joists(joists in the house are 2x12 and run side to side, not front to back). Does that seem even remotely possible? Will a 45 work inside a joist bay?

Finally, are all the connections made using sanitary tees, or wyes?

YUP! Cleanouts needed only at the changes of direction as noted in the drawing.

Cleanouts are just cemented into the end of the wye making the change of direction.

3" pipe going through how many joists...?? A 3" pipe is actually 3.5" and will require a hole about 4" in size... if a fitting goes through a joist the holes will need to be even bigger. If you plan on running this pipe down the middle of the house as presented I would check with the local building inspector on this as building codes require that no more than 1/3 of a joist can be taken away from a joist... and you are exactly borderline on that (or passed it if fitting ends in a joist).

Running down the center of the addition like this could also cause concerns... right? I'm pretty sure you can only be so close or so far from the foundation walls... so again, you will definitely need to check with your local building inspector on this. Let me know what he says here.. OK.?

All connections off the main run will be WYE connections as drawn above.

MARK

Mark-

Thanks, this is all great. You're right on the joist issue. It just isn't worth it... I'd need to go through too many joists, too close to the middle of the home, so I'll be doing a soffit.

I've got some questions about how to pull this all together. Just to make sure we're on the same page, I've annotated your diagram, marking 3 question areas.

A - This connection is similar to many in this layout, but I wanted to make sure I understand how it works. Starting from the left (where it ties in to the main stack), you have 3" pvc pipe which gets connected to a wye. One one end of the wye is a cleanout. The other port connects to 3" PVC pipe which connects to a 45 which connects to other pipe. Is this right? Especially the use of the 45?

B- Can you walk me through plumbing the sink? Obviously there is a p-trap which connects to a horizontal pipe (1.5", right?) which connects(how??) to a 2" vertical stack. So, how specifically does the p-trap connect into the "stack"? Also, is it necessary for the "stack" to be located immediately behind the sink, or can it be located 6-12" to the left or right? And, how does this vertical stack tie into the drain under the floor?

C- On the toilet, I think I've got this one, but just to confirm. You've got a closet flange (which should sit on the finished floor, right?) which connects into a closet bend which connects directly to the 3" drain, right?

Oh, and when this all ties into the main stack, it gets connected using a sanitary tee, or no?

Anything I'm not thinking to ask? Any suggestions? Concerns?

Thank

A) YES

B) 2" Long sweep elbow out of the floor into a 2"x1.5" sanitary tee at about 18" to center off finish floor and 2" vent runs vertical and connects to other vents upstairs.
The stack should go 12" left or right to avoid issues with running into water pipes. The 1.5" pipe goes horizontal to pick up the sink and can be centered or go left or right of the sink center 6" either way (if vanity go left or right... if pedestal sink go dead center). Use a regular 90 to come out of the wall and install the PTRAP.

C) The closet flange sits on the finish floor... correct. Closet bend and then connect direct... correct.

D) At the main stack connect via a sanitary tee.. correct. A long sweep elbow should be installed at the base of the stack and a DANDY CLEANOUT should also be installed (read on).

Plan on capping everything with jim caps (2nd image) or wing-nut plug (3rd image) and fill the system with water to the roof vent to test all this. Here, you can install a DANDY CLEAN OUT (also called a test tee) at the base of the 3" stack and install a cherne seal plug (available at plumbing supply store... (4th image). These cherne plugs screw into the dandy cleanout (last image and in cross section in 4th image) and make it real easy to drain the system after filling the system (just release air from the plug and after all drains remove and recap the cleanout). Or, you could wait to connect the stack to the main and use a jim cap with boiler drain (1st image) in it to drain the system and then make the final connection into the main drain.

MARK

This is all really great. Thanks so much!

Regarding the main stack and then the testing. The stack I am tying into is pre-existing, 3" cast iron. Should I still be planning on adding a long sweep elbow? If so, where?

Now, there is a clean out located below the point where I will be tying in. That's good, right? That said, it's an OLD clean out, 76 years old I am sure, and I have no idea when it was last opened. Can I perhaps use this for the purposes of testing? Also, how does this work given that there is a full bath connected to this stack (one floor above the powder room)? Can I still perform the test? Am I confused on something?

Thanks!

If preexisting stack then no need for the 90 degree fitting... correct.

If you install a dandy cleanout after you connect into the sanitary tee fitting of the stack... say a foot or two after you have connected (between sanitary tee and the wye/45 fitting) then you can install the cherneseal test ball into the dandy clean out, fill with air (PSI recommended on the cherneseal), test the drainage to highest point with water and then let the air out of the cherneseal to let water drain (after approved by the inspector) and then just install the cap back into the dandy cleanout and abandon it under the floor.

This will keep you from having any issues with the upstairs bathroom on this stack... ;)

MARK

I guess I am still a little bit confused by all of this. Sorry!

I have a 3" cast iron vertical stack, it comes up out of the basement floor and runs all the way up the house, through the attic and out the roof. There is already a cleanout in the stack, perhaps 2-3' above the basement floor.

My house has three stories, including the basement. The plan is to run the pipes for the half bath and the washer, both of which are on the main floor of the home, through soffits along the basement ceiling. I did not envision having to open up the floor at all. Am I wrong? So, effectively the 3" horizontal run of the new drain will connect to the existing vertical stack, approximately 5-6' above the basement floor. Does this make sense at all?

So, I am wondering, can I use the cherneseal with the old cast iron clean out?

You said, "So, effectively the 3" horizontal run of the new drain will connect to the existing vertical stack, approximately 5-6' above the basement floor."

Install the dandy cleanout and the chernseal AFTER you connect into the stack... four or five feet off the old stack. Do not use the old cleanout. It will cause you to have to fill some of the old pipes.

Install the dandy cleanout and cherneseal about 5 feet off the old stack, in the ceiling where you will be building soffit around it. That make sense now?

This is great. Makes perfect sense now. Sorry it took me so long to catch on.

I have two quick questions:

1) I'll be plumbing the supply lines with PEX. The supply for the toilet will come out of the floor (as opposed to the wall). How do I pull this off?

2) I will need to run the 2" vent through an exterior 2x6 wall. Will I be OK doing so? What size hole do I need to drill to fit a 2" pipe?

Thanks!

1) You can go with a pex shutoff which would only require you to stub up pex and cap it for now... or you could install a pex x copper adapter and stub up copper pipe and cap off until you are ready to install the shutoff at finish (see image... although shown in wall for the lavatory this applies to below the floor for the toilet just as well).

2) A 2" vent in exterior wall is normal practice. A 2" pipe will need a 2-9/16" hole-saw or self feeder bit.

As always, excellent advice. Many, many thanks. I have a similar question, how about 2x4 non load bearing walls. Can a 2x4 accommodate a 2" pipe? Particularly the top and bottom plate? Are the restrictions related to the vertical studs, or do they apply to the top and bottom plates as well. This bathroom is complicated in that it has brick walls on 2 sides, a 2x6 exterior wall on 1 side and a 2x4 partition wall on the 4th side. I am having a difficult time trying to figure out how to run the vent stack. Any thoughts?

Also, as long as the stack maintains 1/4" per ft slope, is it OK if it has some twists and turns?

Yes... it's tight but we do it all the time.

Twists and turns are fine as long as pitched. You have to get the vent out somehow.

I'll think on it, but best path is obviously the shortest path!

Mark- I've got a bit of a thread going on in construction regarding how to channel brick. I don't want to double post, would you be willing to check out what I've got over there? The link is

https://www.askmehelpdesk.com/constr...ng-375076.html

Thanks!

Mark-

It's been a LONG time... I hope you're still out there. I can't believe it, but we haven't yet started this project, but hopefully we'll be ready to go in the next month or two.

Recently I have been reconsidering the decision to run the drain pipe along the ceiling, rather than underground, but frankly, I am intimidated about finding the pipe under the cement slab.

How do you go about doing this? I'd imagine you have a camera or some high tech tool, but is there an effective method for DIY? I am certain the pipe is cast iron, but frankly, I am not sure quite how deep the slab is.

Someone suggested I run hot water in the pipe and use an infrared thermometer. Have you ever hear of this?

Would a Radio Shack grade metal detector do any good?

Any other thoughts?

If you look at the diagram in Post # 93, it shows the main level of the home, there is a finished basement below. Immediately below the kitchen (shown in the diagram) is a bathroom. The toilet is in the lower right hand corner, meaning a 3" pipe must run from the toilet to the main stack, also shown in the diagram. I would like to tie into this, it seems like the cleaner installation method.

Any thoughts?

Thanks as always!

Ok folks, I am not sure if I should start a new thread or continue this here because of the history. Hopefully people still bother to read it!

If you look back on the discussion you'll see we were planning to add plumbing for a full bath, half bath and laundry room. We've reorganized the layout and now we only need to focus on the plumbing for the half bath. We'll be adding a full bath and a laundry room, but elsewhere.

So, I have a couple of questions just to make sure that the walls are being designed to accommodate the plumbing correctly, especially for the vent.

So, my questions are...

1) Am I correct that I will just need a 2" vent? The half bath will have just a lavatory and a toilet.

2) I read somewhere that I need to increase to 3" when I come up through the roof, is this true? Or is 2" fine?

3) Alternatively, is it OK if I tie into an existing vent, as long as it is above the flood rim of the other fixtures?

4) If I go the above route and tie into an existing vent, is there any limits on the length of the vent line? I know it needs to be sloped, 1/4" per foot? More? Less?

5) The biggest question though, is can a vertical 2" vent line be run safely and code compliant through a 2x4 exterior wall? Is it code compliant? And, if it is, are there any risks during cold weather, etc?

6) Instead of all of the above, what about an AAV? An AAV seems like the perfect option here, but do they really work? I'd have no problem making it accessible, I could cover it easily with a mirror? Thoughts?

Thanks for any insights. I have lots of architectural plans if they'd be helpful.

Hey Stubby, Back again I see.

Quote:

---

1) Am I correct that I will just need a 2" vent? The half bath will have just a lavatory and a toilet.

---

My code, (SPC) will allow 1 1/2" vents but our inspectors prefer 2" vents.

Quote:

---

2) I read somewhere that I need to increase to 3" when I come up through the roof, is this true? Or is 2" fine?

---

2" exiting the roof will be just fine.

Quote:

---

3) Alternatively, is it OK if I tie into an existing vent, as long as it is above the flood rim of the other fixtures?

---

Not just the flood rim of any fixture. There can be nothing discharging above the fixture you're reventing back into, It MUST be a dry vent.

Quote:

---

4) If I go the above route and tie into an existing vent, is there any limits on the length of the vent line? I know it needs to be sloped, 1/4" per foot? More? Less?

---

No limit, 1/4" slope.

Quote:

---

5) The biggest question though, is can a vertical 2" vent line be run safely and code compliant through a 2x4 exterior wall? Is it code compliant? And, if it is, are there any risks during cold weather, etc?

---

Are you asking if you can run the vent outside and up a outside wall. Through the over hang and out the roof? Check with your local Building Department.

Quote:

---

6) Instead of all of the above, what about an AAV? An AAV seems like the perfect option here, but do they really work? I'd have no problem making it accessible, I could cover it easily with a mirror?

---

Yes they work but it will have to be OKed by the plumbing inspector before installing.
Good luck, Tom

Thanks Tom.

Regarding running the vent through a 2x4 wall, I meant can I run it in a 2x4 exterior wall, sorry for the confusion.

I have read different things about the AAVs, I know they need to be accessible, but do they need to have a vent/grate over them to allow them to breath? Could I install it behind a mirror?

Quote:

---

Originally Posted by Stubits

Thanks Tom.

Regarding running the vent through a 2x4 wall, I meant can I run it in a 2x4 exterior wall, sorry for the confusion.

I have read different things about the AAVs, I know they need to be accessible, but do they need to have a vent/grate over them to allow them to breath?

---

Yes, you may take the vent up inside a outside wall.

Quote:

---

Could I install it behind a mirror?

---

They do not require a grate over them and if you place a mirror the mirror must be removable or on hinges to provide access for servicing. Ya just can't place it inside a wal without access to it. Regards, Tom

Thanks Tom, I've spoken with our inspection office before and they are OK with AAVs, they say given how many older masonry homes we have, there is not much choice.

Do you trust AAVs enough to use them yourself? As long as stay accessible? I imagine if anything goes wrong all I need to do is cut it out and put in a new one, right?

So, if all I have is a toilet and a lavatory, how high up does the AAV need to be?