Greetings,

Thank you in advance for you knowledge. Be assured if ever you need electrical advice I will be more then happy to supply you with that. (Master Electrician)

On to the question;
My friend here is renovating his attic to an office. He wants a bathroom in this space as well. Sink, toilet, and shower. There is a 4 inch cast waste stack that I know I will tap into, this stack is in the same bay as the toilets location and about 5ft away. The shower on the other hand is about 6-7 feet away. Now at a ¼ inch drop per foot the 2 inch line that needs to be added along with a trap brings the drainage pipe for the shower up out of the dimensions of the floor. Vertical space is critical for head room and drilling out the 2x6 ceiling joists and ruining their integrity scares the life out of me. My question is, Is there a way to add this shower with out either adding dimensional height to the floor and or cutting into the living space ceiling below.

Please see pictures below.
Red is toilet location
Green is sink location
Blue is shower location.

Thank you again.

I hope the photo link works here. I posted the photo as a profile photo in Yahoo. [email protected]

Albert's profile on Yahoo!

Hi Albert...

Most likely that 4" cast iron stack isn't a waste stack, but a VENT STACK and it is acting as the vent stack for the whole house AND is very likely where the vents from the bathroom below tie into.

Unfortunately, you can't connect into this stack for the upstairs bathroom.

However, you can cut into the waste stack below the bathroom downstairs and run a parallel 3" PVC waste stack up to the attic. If you do this, please consult with us before cutting into a cast iron stack...can be very dangerous work when not done properly!!

After that I would need to know if you plan to pull a permit for this plumbing work? We also need to know what plumbing code prevails in your area so we can tell you how to properly vent all the fixtures. If you are lucky, you can WET VENT the toilet and the shower using a 2" lavatory vent, but we need to know more before describing this to you... ;)

Back to you...

MARK

Your photo didn't upload, OE.

I did have the same difficulty on a job a few weeks ago, though and managed to make it work by using a Brass DWV p-trap and a 2"x1-1/2" Copper DWV combo instead of ABS or PVC DWV fittings.

It was a pain in the butt, especially soldering such big fittings right up against the lathe of the ceiling below, but it all worked out fine in the end.

The brass trap, my cost was just under $95.00 and the copper Combo was about $35.00.

Thank you massplumb2008. This stack goes down behind the kitchen sink. The down stairs bathrooms are connected to a different waste system. As you look at the photo to your left just in the other eve of the house is a 3 in cast vent/stack (?) that handles the bathrooms.

[QUOTE=massplumber2008;1999527]Hi Albert...

Most likely that 4" cast iron stack isn't a waste stack, but a VENT STACK and it is acting as the vent stack for the whole house AND is very likely where the vents from the bathroom below tie into.

Unfortunately, you can't connect into this stack for the upstairs bathroom.

However, you can cut into the waste stack below the bathroom downstairs and run a parallel 3" PVC waste stack up to the attic. If you do this, please consult with us before cutting into a cast iron stack...can be very dangerous work when not done properly!!

After that I would need to know if you plan to pull a permit for this plumbing work? We also need to know what plumbing code prevails in your area so we can tell you how to properly vent all the fixtures. If you are lucky, you can WET VENT the toilet and the shower using a 2" lavatory vent, but we need to know more before describing this to you... ;)

Back to you...

MARK[/QUOTE

Thank you again.


Mark, ( sorry, didn’t see you name before )

There will not be a permit on this job. I am trying to save a friend some money by doing this with him on his house. And to correct myself here, I am not sure if that 4 in is just a vent line or not. I have been known to be wrong. ( just ask the wife ) there is another 3 in cast pipe coming up in the attic on the opposite side almost in the same location. Would it be better to move the bathroom over to that side? And would it also be easier to delete the shower? I can send pictures of the crawl space or any thing else that you need to make a better call on this.

Thanks again. Now I know why you guys make the big bucks!

Al

You won't be able to tie into either of the attic pipes for drainage. You can use either of them for venting purposes. As Mark suggested, you need to run a new 3" line down and tie it in below the downstairs bathroom. You mentioned a crawl space, i suggest taking the new 3" line all the way to the crawl space and tieing into a three inch line there. IF you don't want to cut into walls to run the pipe, try to find a closet or other practical place to run the pipe down.

You being a Master electricain know how hard it is to learn and get licensed for a trade. Takes years and years, and your always learning. We are in the same boat. Its hard to expain how to do it correctly in a matter of days or even weeks. Really hope we can help out a fellow tradesmen. Please keep the questions coming, and someone here will give you the advice you need to make this a pro job. Lee.

Hi all:

Al... if you follow through and actually install the bathroom in the attic then be sure to include that shower. I am sure we can figure something out... ;)

Let us know what you need... O.K.

MARK

Quote:

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Unfortunately, you can't connect into this stack for the upstairs bathroom.
However, you can cut into the waste stack below the bathroom downstairs and run a parallel 3" PVC waste stack up to the attic. If you do this, please consult with us before cutting into a cast iron stack... can be very dangerous work when not done properly!

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And you will come off the 4" stack with a 4 X 3" upright wye, ( 4 X 3 wye with a 3" eighth bend) and raise up to the attic as a stack vent. But before you make the cut the cast iron will have to be propped up with a raiser clamp and 2 X 4's, (see image). Get guidance from us before you make the cut.
Your bathroom will install as follows.
Toilet connects to the stack vent. Lavatory connects to toilet drain and runs a 2" vent off the top the stubout tee out the roof or revents back into a dry roof vent in the attic using a inverted wye.. The toilet wet vents through the lavatory vent and the tub/shower connects to the lavatory drain and is wet vented by it. This is a normal rough in and is acceptable both by local and state codes and also The Standard Plumbing Code Book in 90 percent of the country. Check your local codes to make sure you're not in the excluded 10 percent. More questions? We're as close as a click. Good luck, Tom

Thank you guys so very much for sharing your expertise. At this time I am waiting for the wife of my friend to make the final decision. I "will" be getting back with you all.
Al

I hate computers. Going to try to get this picture up this way




Ok guys here it goes.

Red denotes new waste,
Blue denotes existing,
Green denotes venting

My plan is to take a 3" pvc line to crawl and attach to existing 4" pvc. Up in the attic I will attach my 2" waste line ( shower ) and 1 1/2 waste line ( sink ) Into the new line that is coming from under the toilet.

From my sink I will tap into the existing steel 4" stack with a 1 1/2 vent
From my shower I will tap into the existing steel 4" stack with a 1 1/2 vent.

I am fairly sure that pitch is not a problem with the vents, is this a correct assumption?

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If you go to #12 message and click the link for Facebook it will take you to my pictures and it should ( God willing ) take you to the photo. I am very sorry about the extra posts.

Al

Sorry! Facebook won't let me log in to see.
To Send Attachments
Make your post and scroll down to Manage Attachments click on that and then click Browse This will allow you to get into your computer and retrieve your picture and upload it to The Plumbing Page. Try attaching the drawing. Cheers, Tom

Thanks speedball, going to try that here.

OK! Has a permit been pulled and will this job be inspected? Are wet vents allowed in your area? What's venting the toilet. I see a "P" trap at the base of the stack. What would that be picking up? Regards, Tom

No permits are being pulled. This is an off the radar job. But I still want it right. Just like anything else in life, when you don't have the money... you just don't. That is why I am helping a friend.

As for wet venting I do not know.

The base of the stack, in the crawl ( I am asuming that you are talking about the area just above " to street under ground" that goes to a 1st floor toilet.

The first floor toilet and the upstairs shower are wet vented by the lavatory vent.
Why is the upstairs toilet on a dedicated drain and why isn't it vented? Cheers, Tom

The light blue is what I intend to run. But before I do I wanted to ask you guys if this is acceptable. I thought as I was tying into the pvc in the crawl the existing stack would act as vent. If I need to vent the new 2nd floor toilet how would I go about venting that?

Quote:

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I thought as I was tying into the pvc in the crawl the existing stack would act as vent.

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The distance is too great for the blue line to vent the upstairs toilet. In place of the downturned elbo ,( in red)I would install a 4" combination wye and eighth bend and bush the top of the combo down to two inches. Then run 2" PVC up and elbo overto a inverted 2" sanitary tee in the exixting VTR at least 6" over the top of the lavatory flood rim. Good luck, Tom

Hi Guys... hoping this helps a bit.

In the attic you will take off the stack with a 3" sanitary tee to pick up the entire bath. Run that 3" directly to the toilet and end with toilet elbow. In between, install a 3"x2" WYE fitting to pick up the lavatory and the shower. The lavatory waste and vent are increased to 2" and act as a WET VENT for the shower and the toilet. Penetrate the roof with 3" vent up to 18-24" if snows in your area, or less if no snow... ;)

Let us know if you have questions...

MARK

Mark,

In this diag, you show me tapping into the 4in waste stack. Is this right or am I still running a new 3" PVC to the crawl?

Hi OE:

I can see why EXISTING STACK would confuse the issue. Somehow I thought you had already run the 3" up.

I am afraid you are running the 3" up from the crawlspace! No getting around that! UGH!

Pop back anytime!

MARK

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