[KRO]

Hello, need help
House is on a slab.(built in 1952). I have an existing floor drain in the middle of the dinning room. It does nothing. After getting some new furnace quotes, the salesman said that moving the drain into the area of the furnace and hot water heater, would allow me to go high efficiency, due to the furnace needing a drain. Otherwise I would have the drain pipe for h20 heater and furnace stretched across my dinning room floor.

From the old floor drain, I have busted out a ten foot trench in the concrete. Eight foot straight, 2 foot "dog leg" at the end. This puts me into the furnace room. After cutting into the old drain / pipe to make a connection, I found the old (4inch, cast iron) pipe goes into the ground (has a P trap) then onward.

QUESTION: I have talked to a person that said I cannot use that trap as a RUNNING trap, and extend the (new) pipe another ten feet? He said dig out that OLD P trap, then connect the old pipe to the new extension. Then put a new P trap at the start of my new drain.

I have some SPACE concerns. What is the right way to do this. I have bought all 4 inch pvc for the new extension. A 4 inch p trap would not fit in the space I have busted out. If I have to add a new P trap at the start, can that be smaller dimeter (2 or 3 inch) just to clear the space, then connect to the 4inch new pipe? Would that be code?
Lastly, would the new system work with having both the new and old traps together?

Right now I have 1/4 per foot drop. That might change if I have to dig out the old P trap.

Thank you, KRO

Mr. Speedball Sir, I THANK YOU! I HEARD you're the best.

I went with 4" inch pvc, because thats what the guy sold me? I was also worried, that If my h2o tank ever let out (broke) it would drain into the drain, and a 4" would be better?

[B][I](YOUR question) Add a new trap at the start? The start of what? [ I meant the "NEW drain cap" , the start of my extension
If this were my job I would cut out the 4" trap and floor drain and reduce down to 2". I would then run 2" over to a new 2" floor drain.

Is two inch acceptable? The guy that sold me PVC, said to just put a "push in" drain cap into the 4" hole for my drain cap. Will a two inch, drain pipe handle the flow of a H2O heater if it breaks and a humidifier (on furnace and AIR conditioning drain/ summer)? The guy I talked to (much like you stated) 4" is overkill.

Do you advise to buy a "preformed"? Drain then pipe off that? DO I have to worry about any venting issues, with floor drains? Or just hook up to the OLD one ten feet away, and get it done?

I am new to this site (just found it). I love it. I thank you for any and all advice.
The guy that came over to look, said his company would have already charged 2K, for what I did myself, for the cost of a jack hammer and cement saw +a lot of sweat! Don't mind the hard at all.

NOTE : this drain extension is only intended to handle a h2o and furnace with runoff from humidifier and air.

I just measured down from the top of drain to the "old" P trap, depth is 30" below the slab. I'm in Michigan.

With GREAT RESPECT to you SPEEDBALL ,
Thanks for the help ~ KRO

KRO here,:)

Asking a follow up question... Under slab moving drain

TO SPEEDBALL1; I misspoke about the four inch drain. I have three inch cast iron. I followed the advice, dug out the old trap (so not to double trap) and now have the old pipe w/o p trap sitting there. And here's where I stand now.

I have a "rat wall" that the new P trap will be located just above, and go over to drain into the old cast iron pipe. I have jack hammered out about 8 inches above the rat wall, to give me enough room for schedule 40 / 3 inch pvc and concrete to cover pipe above.

I have added a drawing, with my SIGN on, I know it's small.
MY QUESTION: The "old" cast iron pipe is now 24" inches below the concrete. TOTAL RUN length will be almost nine feet. My new drain will be located, about 4.5 inches at the start I have no idea where the vent might be? Again this is a floor drain.

With the Rat wall issue, I will be able to maintain, a 1/4 inch drop per foot for the first seven feet then, it will forty five down into old cast iron pipe.
SO within that last foot or so, it will drop (45 elbow) , 14 inches into the old cast iron and drain out.
WOULD THIS WORK? I have water pipes running all under the slab, thus making it difficult to dig anymore.

A local plumber in (MI) said that would work, but yet he did not see the job, only from me explaining it to him.

HELP. KRO


PHOTO: above... the right of the pix, is the new drain, and Ptrap. It will drain to the left and drop down about three quarters into the pix. OLD drain, I'm connecting to is on the left side of pix.

[speedball1]

QUESTION: I have talked to a person that said I cannot use that trap as a RUNNING trap, and extend the (new) pipe another ten feet? He said dig out that OLD P trap, then connect the old pipe to the new extension. Then put a new P trap at the start of my new drain.
I have some SPACE concerns. What is the right way to do this?

The correct way would be to dig out the old trap because the newer floor drains have the trap built in and you can't double trap the new floor drain.

I have bought all 4 inch pvc for the new extension. A 4 inch p trap would not fit in the space I have busted out.

Why would you need a floor drain that large? A 4" floor drain is mostly used in commercial buildings.

A 4 inch p trap would not fit in the space I have busted out. If I have to add a new P trap at the start, can that be smaller dimeter (2 or 3 inch) just to clear the space, then connect to the 4inch new pipe? Would that be code?

Add a new trap at the start? The start of what?
If this were my job I would cut out the 4" trap and floor drain and reduce down to 2". I would then run 2" over to a new 2" floor draim.

Lastly, would the new system work with having both the new and old traps together?

Code forbids double trapping any fixture.

Right now I have 1/4 per foot drop. That might change if I have to dig out the old P trap.

If space gets tight it's acceptable to drop to 1/8th per foot. Good luck, Tom

[KRO]

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