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View Full Version : PVC to Cast Iron in basement & pictures!


kvilesus
Jan 31, 2009, 08:54 AM
We are in Nebraska- we have posted a similar question, but we have some pictures and new concerns. We would like to tie into this cast iron soil stack, but it appears we will have to come in right at the 2 45* cast iron elbows in which the top hub is only 6" below the concrete floor. This is so we have proper slope/drainage from the shower being installed. Toilet drain is adjacent to soil stack- was told OK to tap into toilet drain. Is this correct? What is the best way to vent the shower? Here are some pics attached.
We were previously told to use a "black sealant" with the pvc to seal the shielded rubber claimp to cast iron & pvc. What is the name of "black sealant" used to seal these joints?

massplumber2008
Jan 31, 2009, 09:36 AM
Hi Kvilesus...

Looking at the pictures I think it will be messy if you start trying to connect into the base of the stack where the 45s are... will need to offset and connect back into the stack. There is probably a lot of cast iron above there, too, so heavy and dangerous work.

I'm afraid that you will be best off to remove that toilet and then chop out the concrete and remove the dirt down to the level just below the toilet pipe. After all is exposed you can cut into the cast iron pipe and transition over to PVC with the correct clamp and sealant (available at a local plumbing supply house).

After that transition is made to PVC you will install a 3"x2" wye fitting (or a 4" x 2" wye fitting if pipe is 4") so that the wye rolls above the center line of of the pipe and then run that 2" pvc pipe over to the shower area. Then finish piping so complete the toilet rough in (11.5" to 12" from finish wall to center of the toilet pipe).

About 1-2 feet from the p-trap for the shower you will want to install a 2" wye fitting for the toilet/shower vent. This 2" vent will need to run up the wall and connect into a vent in basement (at lav.) or run the 2" vent upstairs and connect into a vent up there. This is effectively WET VENTING the toilet with the shower.

Remember to pitch the pipe to shower at 1/4" pitch per foot!

If I had gotten to you sooner I may have suggested connecting into the lavatory pipe underground... but that may or may not have worked anyway! You are where you are now, so just keep pushing... looks like half the work is done... ;)

Let me know what you think...

MARK

kvilesus
Jan 31, 2009, 01:29 PM
Hi Kvilesus...
Looking at the pictures I think it will be messy if you start trying to connect into the base of the stack where the 45s are....will need to offset and connect back into the stack. There is probably alot of cast iron above there, too, so heavy and dangerous work.
I'm afraid that you will be best off to remove that toilet and then chop out the concrete and remove the dirt down to the level just below the toilet pipe. After all is exposed you can cut into the cast iron pipe and transition over to PVC with the correct clamp and sealant (available at a local plumbing supply house).
After that transition is made to PVC you will install a 3"x2" wye fitting (or a 4" x 2" wye fitting if pipe is 4") so that the wye rolls above the center line of of the pipe and then run that 2" pvc pipe over to the shower area. Then finish piping so complete the toilet rough in (11.5" to 12" from finish wall to center of the toilet pipe).
About 1-2 feet from the p-trap for the shower you will want to install a 2" wye fitting for the toilet/shower vent. This 2" vent will need to run up the wall and connect into a vent in basement (at lav.) or run the 2" vent upstairs and connect into a vent up there. This is effectively WET VENTING the toilet with the shower.
Remember to pitch the pipe to shower at 1/4" pitch per foot!
If I had gotten to you sooner I may have suggested connecting into the lavatory pipe underground...but that may or may not have worked anyway!! You are where you are now, so just keep pushing...looks like half the work is done...;)
Let me know what you think...
MARK

MARK- WE ARE ATTACHING ADDITIONAL PHOTOS - IS THIS THE LAV PIPE YOU ARE REFERRING TO? We removed more dirt and this is lo and behold what we found! This pipe is coming from the laundry room (on same floor as new bath) and kitchen (directly above laundry room). This is a 2" pipe which ties into toilet drain, which ties into the main drain. Toilet is 32" from this main drain; and this 2" pipe is 13 1/2" below grade. Shower will be appx 6' from this 2" pipe. Shower drain can be a pretty aggressive slope; does it need to be vented? Will having a more aggressive slope hurt anything ir can it be a substitute for a vent due to the proximity of the shower? We would still like a name for the black sealer-- do you have one? Thanks for all of your expertise and assistance! It is much appreciated!!

massplumber2008
Jan 31, 2009, 02:51 PM
Hi again:

Are you pulling a plumbing/electrical/building permit on this job?

If this 2" pipe attaches to a washing machine or a kitchen sink on floor above then you may not use it to install a flat bottomed fixture (a tub or a shower)... at least that is how the code reads in my area. Here, if kitchen sink, for example, clogged up before the new shower connection then all waste water and say all disposal waste could simply collect in the tub or shower almost INDEFINITELY if knowone was paying attention and that would create one hell of a mess and one hell of a health hazard as mold/bacteria grew exponentially! Further, if shower pipe was attached to the washing machine pipe and we tried to use the washer vent as the shower vent the p-trap to the shower could still be siphoned out due to the great volume of water discharged and this could let sewer gasses enter into the house... another health hazard and super smelly, too. So not looking promising to connect onto there...

Any chance you can confirm if this pipe goes to a sink in this same room? Or in the laundry room? Is there a sink in the same room as the toilet? If not, are you planning to add a sink??

See if you can chase that 2" pipe out entirely... exactly what is on it.. exactly... if possible?

Also note that a vent will definitely be required.. question is if we can use an already existing vent or if you will need to run a new one.

Answer all questions if possible.

MARK

kvilesus
Jan 31, 2009, 04:08 PM
Hi again:
Are you pulling a plumbing/electrical/building permit on this job??
If this 2" pipe attaches to a washing machine or a kitchen sink on floor above then you may not use it to install a flat bottomed fixture (a tub or a shower)...at least that is how the code reads in my area. Here, if kitchen sink, for example, clogged up before the new shower connection then all waste water and say all disposal waste could simply collect in the tub or shower almost INDEFINITELY if knowone was paying attention and that would create one hell of a mess and one hell of a health hazard as mold/bacteria grew exponentially! Further, if shower pipe was attached to the washing machine pipe and we tried to use the washer vent as the shower vent the p-trap to the shower could still be siphoned out due to the great volume of water discharged and this could let sewer gasses enter into the house....another health hazard and super smelly, too. So not looking promising to connect onto there...
Any chance you can confirm if this pipe goes to a sink in this same room?? or in the laundry room?? Is there a sink in the same room as the toilet? If not, are you planning to add a sink??
See if you can chase that 2" pipe out entirely...exactly what is on it..exactly...if possible?
Also note that a vent will definitely be required..question is if we can use an already existing vent or if you will need to run a new one.
Answer all questions if possible.
MARK

Hi again, Mark!
MAKES PERFECT SENSE! No sewer smells in the house desired! No backed up stuff in the shower desired, either!
Q1- :) Takin' the 5th :o
Q2- There is no sink existing in the room at this time; there WILL be- it will be placed next to the toilet. In the laundry room, there was a sink in the there, but it has been since torn out- that is a dead end.
Q3 - on that 2" pipe-- exists the floor drain and the washing machine -- and the kitchen sink, it appears!

There is a bathroom above this bathroom that has a bathtub vent routed through the wall upstairs; was thinking about tying into this vent for the shower or tying into our sink vent, which will be located between the toilet and the shower. We were going to route the sink drain and vent in the wall behind the toilet to the main soil stack. Can we install a backflow valve for the shower so there will be no back-ups into the shower?

It's been a long day! Thank you!

massplumber2008
Jan 31, 2009, 04:19 PM
OK...

I think you can WET VENT the entire bathroom off one 2" vent... see picture. This is referred to as WET VENTING the fixtures and may or may not be allowed in your area, but is allowed most places so rest assured it will work fine. Here, the 2" sink vent acts as a vent for the toilet , the shower and of course the sink itself.

Check out my drawing. I guessed where you would locate fixtures but the basic idea will be the same no matter. Here, you will cut into the toilet pipe and then transition over to PVC using a mission clamp that transitions from cast iron pipe to PVC (see picture of shielded clamp). Then you will add a 3"x2" wye (or 4"x2" wye) and you will roll that above the center of the toilet drain pipe and run that pipe to the sink and shower as drawn. The 2" vent will run upstairs and connect into the toilet/sink vent if possible up there (2" or larger vent is best size to connect onto). After the 3"x2" (or 4"x2" wye) you will just need to add a long sweep elbow to pick up the toilet and you should be all set.

There is more to tell you in terms of cleanouts, boxing out for shower and building up around the toilet pipe, but I'll save that for later... ;)

Let me know if this makes sense...

MARK

kvilesus
Jan 31, 2009, 04:33 PM
OK...
give me 5-10 minutes and then check back...think I have the solution here.

No rush-- dinner is callin' - we'll check back! Thanks!

massplumber2008
Jan 31, 2009, 04:34 PM
Check my answer in post #6... let me know.

zosoplumber
Jan 31, 2009, 04:41 PM
Mass seems to know what he's talking about, just a quick question, how is the toilet vented? If it is vented then you could just tie in your shower vent to the toilet vent above flood rim.

massplumber2008
Jan 31, 2009, 04:59 PM
Good question Zosoplumber...

When he unearths the rest of the dirt by the toilet drain may be that he will find the vent. That would certainly be helpful.. :) He could tie all vents into that vent at about 48" off finish floor.

Let us know kvilsus...

MARK

kvilesus
Jan 31, 2009, 05:21 PM
Check my answer in post #6...let me know.

Wow! Love the drawing, thank you! This was originally why we broke out the extra concrete to access the toilet drain. However, we ran into the same problem- as previously- we have 2- 45* elbows coming out of the toilet drain and we have a Y for the
2" drain, so there appears to be no straight pipe to connect to. This is why we were tickled when we found the 2" straight piece, which is going into the toilet drain, anyway.

What now? Can we tie into that piece from the right? There appears to be no (easy) access to the 3" pipe. But the 2" we can go right into it; right next to the 3" x 2" Y. There are 2-45* elbows & 2- Ys back to back between the toilet & the main drain.

Any other considerations would be appreciated. What about the back-flow valve?
Tomorrow is the Lord's Day, so we will not be working on this, so no rush!

massplumber2008
Jan 31, 2009, 05:28 PM
No need for check valve here... won't be accessible so a NO-NO!

Can you post a picture of ALL the pipes exposed and show where the sink and shower are going? Let me know. Monday is fine.

kvilesus
Jan 31, 2009, 05:59 PM
Good question Zosoplumber...

When he unearths the rest of the dirt by the toilet drain may be that he will find the vent. That would certainly be helpful..:) He could tie all vents into that vent at about 48" off finish floor. Let us know kvilsus...
MARK

The toilet is vented through the main stack, there to the right on the pics- this is where we were also planning on tying the sink and the sink vent into (running them parallel across the back wall behind the toilet). Keep shooting your questions and comments! Can supply a drawing if we HAVE to-- not our specialty, though. :D

massplumber2008
Jan 31, 2009, 06:02 PM
Actually... if there are ANY fixtures that connect onto that stack above this bathroom then that stack DOES NOT act as a vent for the toilet. I will only mention the fact that the laundry and kitchen and laundry are on the toilet line before connecting into the main system/stack. Here, toilet is either UNVENTED or you have yet to expose the vent.

Expose the pipes and post a pic... :)

kvilesus
Jan 31, 2009, 06:37 PM
Actually... if there are ANY fixtures that connect onto that stack above this bathroom then that stack DOES NOT act as a vent for the toilet. I will only mention the fact that the laundry and kitchen and laundry are on the toilet line before connecting into the main system/stack. Here, toilet is either UNVENTED or you have yet to expose the vent. Expose the pipes and post a pic...:)

OK - here we go! MORE PICTURES!
Pic 1 Shows to the right- the stack; to the left of the stack (in the center of pic) the toilet flange; where the dirt pile is- this will be the sink (in the corner). We are going to frame in the concrete wall and run sink drain and vent pipes through wall to stack.

Pic 2 Shows between garbage can and shovels, is where shower is to be located. We are aware that we will need to build a 1' box for p-trap.

Pic 3 Shows overall view of "drainage trench" :) You can see the 2" pipe cross the trench before the "straightaway".

Pic 4 Shows Upstairs bathtub P-trap which connects to 1 1/2" vent stack which goes into wall. This is directly above our shower location and we were thinking about venting here or tying into sink vent.

If we do not have to dig out the toilet flange, we would prefer not to. Gentlemen-- have a glorious day in our Lord Jesus Christ! :D We will check back in on Monday! God bless you all!~

massplumber2008
Jan 31, 2009, 06:51 PM
We'll break this down and then talk on Monday. Plan on exposing the toilet pipe completely... ok?

Good night!