Is it a bad idea to place a toilet at end of the main drainage Line. Planned on the vent stack being in the corner of the building followed by the toilet, shower, bath sink, washer, ending with the kitchen sink. These will all be on one wall making the main drainage line one strait pipe, but didn't know if a toilet at the end of the line was mechanically a bad idea.

Hi Isblpn

I see no issue with putting a toilet anywhere in relation to the drain system... ;)

I do, however, see an issue with what you present as your VENT system.

Here, for example, in some states you need to individually vent each plumbing fixture (each fixture gets its own vent and then all vents connect together into the vent stack at the appropriate height off the floor), or as in some states you can WET VENT your bathroom (means the toilet, sink and tub/shower can share the same vent), but the washer drain and kitchen sink MUST have their own vents, etc...

Let me know what state you are from and let me know more on how you plan to vent everything, OK?

Mark

Mark,
Thanks for your reply. I live in NC. If you tie into the main vent stack after each fixture for venting, can you explain how this done.

Hi Isblpn

I see no issue with putting a toilet anywhere in relation to the drain system...;)

I do, however, see an issue with what you present as your VENT system.

Here, for example, in some states you need to individually vent each plumbing fixture (each fixture gets its own vent and then all vents connect together into the vent stack at the appropriate height off the floor), or as in some states you can WET VENT your bathroom (means the toilet, sink and tub/shower can share the same vent), but the washer drain and kitchen sink MUST have their own vents, etc....

Let me know what state you are from and let me know more on how you plan to vent everything, OK?

Mark

Here's what NC code says.
912.2.1 A combination waste and vent system,(wet vent) is limited to sinks, dishwashers, floor sinks, indirect waste receptors, floor drains or similar applications where the fixtures are not adjacent to walls or partitions. It consists of the installation of waste piping in which the trap of the fixture is not individually vented.

Since wet venting is allowed in your area it is exactly as I presented in my first post on wet venting. Here, "your bathroom (means the toilet, sink and tub/shower can share the same 2" vent), but the washer drain and kitchen sink MUST have their own vents, etc."

This means that the toilet and shower/tub use the sink drain and vent to "wet vent" the bathroom group. As noted, the washer and kitchen sink get their own vents and these vents connect together and connect into the vent stack.

Vents must pitch from the stack toward the drains they vent so any rain water or condensation build up can fall down the drain via gravity.

You can google "basic venting plumbing" to learn more on how to pipe a vent system. Google "wet venting" a bathroom group under google images to see how that works, too!

Mark

Here's a typical bathroom wet vent installation in my area, good luck, Tom

I appreciate all the input guy's. I have read up on what you all have recommended. Wanted you guys to look over my proposed layout. Try to attach it here.

Try this, easier to read.

See my picture below... should get you started in the right direction. Questions? Let me know, OK?

Mark

Follow Marks advice, "S" traps are a plumbing No-No. Here are some more outlawed traps. Good luck, Tom

Why you going through the exterior wall and then through the roof? Plays hell with siding, soffits and gutters. Why not go straight up through roof?

Answer Harold's question and then please note that in my drawing I have shown the PTRAP going to the washer as being below the floor. It is only drawn below the floor... should be instalkled above the floor is all, OK?

Mark

Mark,
Thank you so much for the design advice. Will do it your way.

1. Are the PTraps bought as separate units with cleanouts?
2. No problem putting the ptrap above the floor on Washer.

Tom,
Thanks for the input on the traps.

Harold,
The reason for the stack there is it's a metal roof and exiting through the endwall and going through the roof there will minimize the chance for leakage inside the house.
1. Is it OK to run the stack like that? Will that have any affect on proper venting?

Yes, PTRAPS are purchased as separate units with cleanouts.

It is OK to run the stack as you presented... ;)

Mark

Harold asks,
Why not go straight up through roof? Or you could simply run to the attic and revent back into a existing roof vent using a inverted sanitary tee. Good luck, Tom

And in post #12 Isblpn answered, "Harold,
The reason for the stack there is it's a metal roof and exiting through the endwall and going through the roof there will minimize the chance for leakage inside the house."... ;)

That's the reason I gave for reventing back in the attic, Regards, Tom

Guy's
Thank you so much for the input!! You guy's are the best. I really appreciate it!
Larry

Please let us know what you decide and how you made out. Good luck, Tom

Will do Tom. Try to take some pics as I go. Thanks again!
Larry

Did have one other question guy's. Should the toilet drain into a wye at the beginning of the main line or strait it?

As shown in my drawing... can only use WYE fittings on the horizontal drains.

Sanitary tees can be used on the vertical for drains and on the horizontal for VENTS ONLY... ;)

Mark

Thanks Mark!

See my picture below...should get you started in the right direction. Questions? Let me know, OK?

Mark

Hi Mark and Tom,
About Ready to do the install on the drainage system you guy's helped me design. I have encorporated everything you guy's have suggested. I had to make a modification due to space considerations. I have moved the lav sink to the other side of the Bath. I have scanned this new layout along with the plan you helped me design. Wanted to get you input on the right way to vent the lav sink in this new configuartion. Can you please comment on this.
Larry

Hi Larry

By moving the sink to that wall you have changed everything as you now have the washing machine wet venting the toilet... a no-no, for sure.

Go back up to post#6 by Tom... shows how to do this correctly. Here, the lav. Waste and vent are in the same wall... run that vent over to the vent stack. All the rest remains the same. NOTE HERE: Be clear that the shower and sink drain need to connect into the toilet drain directly as shown in the draing at post#6

Mark

A click on the helpful icon would be appreciated... ;)

Hi Larry

By moving the sink to that wall you have changed everything as you now have the washing machine wet venting the toilet...a no-no, for sure.

Go back up to post#6 by Tom...shows how to do this correctly. Here, the lav. waste and vent are in the same wall...run that vent over to the vent stack. All the rest remains the same. NOTE HERE: Be clear that the shower and sink drain need to connect into the toilet drain directly as shown in the draing at post#6

Mark

A click on the helpful icon would be aapreciated...;)

Mark,

Thanks again for working with me. Hope I don't seem too dense, but I don't completely understand how to do that vent method with my layout, so I have gone back to the drawing board to offer up another possible layout that I hope you guy's will look at. I am attaching the new layout here. My concern with this layout is that the lav drain may violate critical distance. Look forward to your input.

Mark,

Thanks again for working with me. Hope I don't seem too dense, but I dont completely understand how to do that vent method with my layout, so I have gone back to the drawing board to offer up another possible layout that I hope you guy's will look at. I am attaching the new layout here. My concern with this layout is that the lav drain may violate critical distance. Look forward to your input.

P.S Mark,
Do the horizontal vent connections to the main need to be wye's or Tee's.

I can also extend the vent system around the corner to the lav if you think that's a better way to go? Distance from the lav sink to the drain in the current config. Is 6 feet.

Check out the drawing below... may need to modify a bit here. You MUST have a 2" vent off the lav. (sink) drain. That vent needs to go up into the joist bay and connect into the other 2" or larger vent stack.

The connection for the sink drain/shower MUST connect into the branch of the toilet drain... see drawing. If this isn't clear then you are at a point where you need to bring a licensed plumber in to help!

Moving that sink cost you some labor, for sure!

Mark

Check out the drawing below...may need to modify a bit here. You MUST have a 2" vent off the lav. (sink) drain. That vent needs to go up into the joist bay and connect into the other 2" or larger vent stack.

The connection for the sink drain/shower MUST connect into the branch of the toilet drain...see drawing. If this isn't clear then you are at a point where you need to bring a licensed plumber in to help!

Moving that sink cost you some labor, for sure!

Mark

Doesn't your drawing wet vent the toilet with the washer again which you said was a no no?

Check out the drawing below...may need to modify a bit here. You MUST have a 2" vent off the lav. (sink) drain. That vent needs to go up into the joist bay and connect into the other 2" or larger vent stack.

The connection for the sink drain/shower MUST connect into the branch of the toilet drain...see drawing. If this isn't clear then you are at a point where you need to bring a licensed plumber in to help!

Moving that sink cost you some labor, for sure!

Mark

Mark,
I have tried another configuration for you to look at (See Attachment). It wet vents the shower to a lav sink stack/drain. Is this o.k.
Also you said on the previous layout that the lav and shower MUST vent into the toilet drain before going into the main, can you explain this?

My drawing in post #26 certainly doesn't show the washer wet venting the toilet... look again! What you see in the top down drawing is my representation of the bathroom ONLY (the rest was fine). The wye off the toilet drain picks up the sink and shower and the sink vent acts to wet vent the toilet and shower. Looking at the front diagram should make it obvious after that.

I would not change the coinfiguration again and you are still missing out on how to wet vent anything.

Investigate wet venting online abit, then reread this and it should make sense.

Good luck!

Mark

My drawing in post #26 certainly doesn't show the washer wet venting the toilet...look again! What you see in the top down drawing is my representation of the bathroom ONLY (the rest was fine). The wye off the toilet drain picks up the sink and shower and the sink vent acts to wet vent the toilet and shower. Looking at the front diagram should make it obvious after that.

I would not change the coinfiguration again and you are still missing out on how to wet vent anything.

Investigate wet venting online abit, then reread this and it should make sense.

Good luck!

Mark

Mark,
Thanks for all your help!! I will learn what is necessary about wet venting, but It is already clearer after what you wrote. I think I have learned a ton since my first post with you and Tom, but it's clear I still have a lot to learn.
Larry

My drawing in post #26 certainly doesn't show the washer wet venting the toilet...look again! What you see in the top down drawing is my representation of the bathroom ONLY (the rest was fine). The wye off the toilet drain picks up the sink and shower and the sink vent acts to wet vent the toilet and shower. Looking at the front diagram should make it obvious after that.

I would not change the coinfiguration again and you are still missing out on how to wet vent anything.

Investigate wet venting online abit, then reread this and it should make sense.

Good luck!

Mark

If I could please ask one more easy question. How far from the toilet flange should the tie in from the lav/Shower drain be?

Anywhere between 1-6 feet, and that wye fitting must ROLL above the centerline of the toilet drain to be an actual vent. The toilet drain and the wye must be on the branch of the toilet drain BEFORE it connects to the main drain... look at pictures above.

Anywhere between 1-6 feet, and that wye fitting must ROLL above the centerline of the toilet drain to be an actual vent. The toilet drain and the wye must be on the branch of the toilet drain BEFORE it connects to the main drain....look at pictures above.

Thanks Mark,
Tried to put your idea down on paper. Did I get it right?

Repost... drawing didn't make it!

Repost...drawing didn't make it!

O.k. guys, have some pics of my rough in I wanted you guys to take a look at. Nothing is glued yet. Wanted to get your opinion if it will work. Had to make a few adjustment based on elevation to the tank, but I think I incorporated all of the suggestions you guys gave me.
Like to know if the clean out is OK in this location.

Everything looks good except:

The vent stack must be 3" minimum size (connects into main drain 3" and exits the roof 3" as in your drawing) through the roof... unless you have another 3" vent stack going through the roof in the house and then a 2" vent stack would be fine here.

You need to invert (turn upside down) the tee fitting where the lav./washer vent connect into the vent going through the roof.

Otherwise, the cleanout is in good placement and add hangers every 4 feet, especially on the larger piping.

You didn't show a picture of your washing machine vent connection or PTRAP... post that if you want any feedback on it.

Everything looks good except:

The vent stack must be 3" minimum size (connects into main drain 3" and exits the roof 3" as in your drawing) through the roof...unless you have another 3" vent stack going through the roof in the house and then a 2" vent stack would be fine here.

You need to invert (turn upside down) the tee fitting where the lav./washer vent connect into the vent going through the roof.

Otherwise, the cleanout is in good placement and add hangers every 4 feet, especially on the larger piping.

You didn't show a picture of your washing machine vent connection or PTRAP...post that if you want any feedback on it.

I knew that you'd pick up on that Tee lol! That was already fixed before you even saw the pic's.

Not a major issue on the three inch stack can change that relatively easily. Does it need to be 3" above the kitchen tee through the roof or can it be just 3'' from that tee down to the tank?

Washer stack is the one to the right of the kitchen stack inserted in a rolled up wye. Should be o.k.

Haven't roughed in the p-traps for anything yet. Wanted to have you look at it first. P-Traps will be next. Do the traps have to be any certain height below the sinks? Planned on the same 1/4 inch per foot drop from the traps to the tees.
Don't think I could have done this without you mark. Very much appreciated!!

Larry

3" needs to start at the main, go past the kitchen and up through the roof. The height the 3" vent goes above the roof depends on your local plumbing code... higher here in Mass. for example (18-24" above roof) as compared to Florida (6" above roof), so check requirements for your area.

Sanitary tee for the bathroom sink should be installed so that the pipe under the vanity ends up at about 18"-20" off the finish floor at the vanity.

Sanitary tee fitting for the kitchen sink should be installed ao that the pipe going into the sink base ends up at about 12"-15" off the finish floor under the kitchen sink, especially if you are installing a disposal. Install a 2" drain and 2" cleanout under the sink.. can reduce to 1.5" trap after that.

Ptrap for the washer wants to be at about 6 inches above the floor and the standpipe out of the Ptrap needs to come above the washing machine by a couple/few inches.

When I asked about the washer I was asking about the vent fitting and its orientation... should be installed backward so water will flow down the vent and into the drain... just double check that, OK?

Also note that the closet flange wants to be installed ON TOP of the finished floor, so for now, just stub up a pipe with a cap and then later you can cut the pipe down flush to the floor and install the flange properly. A closet flange with a METAL RING will be a better choice for you, too!

Final note is that you CANNOT use that perforated strapping seen in the pic.s as permanent hangers... must install galvanized pipe hangers/clips or J hook hangers (see images).

When you get ready to test this, pop back and we'll let you know how we do that, OK?

Mark

3" needs to start at the main, go past the kitchen and up through the roof. The height the 3" vent goes above the roof depends on your local plumbing code...higher here in Mass., for example (18-24" above roof) as compared to Florida (6" above roof), so check requirements for your area.

Sanitary tee for the bathroom sink should be installed so that the pipe under the vanity ends up at about 18"-20" off the finish floor at the vanity.

Sanitary tee fitting for the kitchen sink should be installed ao that the pipe going into the sink base ends up at about 12"-15" off the finish floor under the kitchen sink, especially if you are installing a disposal. Install a 2" drain and 2" cleanout under the sink..can reduce to 1.5" trap after that.

Ptrap for the washer wants to be at about 6 inches above the floor and the standpipe out of the Ptrap needs to come above the washing machine by a couple/few inches.

When I asked about the washer I was asking about the vent fitting and its orientation...should be installed backward so water will flow down the vent and into the drain...just double check that, OK?

Also note that the closet flange wants to be installed ON TOP of the finished floor, so for now, just stub up a pipe with a cap and then later you can cut the pipe down flush to the floor and install the flange properly. A closet flange with a METAL RING will be a better choice for you, too!

Final note is that you CANNOT use that perforated strapping seen in the pic.s as permanant hangers....must install galvanized pipe hangers/clips or J hook hangers (see images).

When you get ready to test this, pop back and we'll let you know how we do that, OK?
Mark

Mark,
Thanks again!! I have paid attention to what you've said about tee and wye orientation, such as turning wye's up past the center line, and vent orientation vs. drain orientation with tees. I just brain farted with that one tee.
I will get the right pipe supports as you suggest.
Great tip on the closet flange. Never would have thought about Clearance for flooring.
I get what your saying about drain height. How does this relate to stub out height on these tee's given I'll want a 1/4" drop to these tees. Just measure distance, then drop, then install my tee's?

I will get pic's of all trap connections as well as Tee orientation once I get there. Wanted to get the rough in done so I can start on the supply side. Hopefully working with pex will be less physically demanding than this 3" pipe has been! Lol

example:

Measure the distance from the tee connection to the bathroom sink and then calculate a 1/4" per foot of distance between them...let's say 5 feet here, so 5 x 1/4" = 1-1/4" pitch.

Since I want the pipe (elbow going into sink) at my bathroom sink to be at 20" (this example) off the finish floor I would install my sanitary tee fitting at (20"-(1-1/4")) 18.75" to the center of the sanitary tee fitting. This puts the center of my elbow coming out of the wall at the sink at 20" to center. After testing for leaks you would install the PTRAP during the finish phase and you are all set!