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Making new plumbing connect to old Cast Iron plumbing

7K views 12 replies 5 participants last post by  fallvitals 
#1 ·
Hello all, first time posting here. To put it plainly the plumbing in my bathroom is a mess. Instead of telling storys I'll get right into it. I can do about most any thing, but I may not know all the correct terms, so bare with me.

This jack legg was hired before I moved into this place by someone else to fix a few things. He replaced the floor in the bathroom (the plywood, top layer), well it seems all of it except around the toiler which, after I thought I had a bad wax ring (had a leak), found out the floor is so rotted around the toilet, there is not enough material for the toilet flange to bolt to so the toilet is just sitting there.... (naturally, this is afterI removed the toilet flange, but it really wasnt doing much work as is, lol)



Now the floor, iv never done, but I can make it work. My problem is connecting into what will be the new PVC and toilet flange into the cast iron plumbing below. Currently a, thin metal pipe just dumps right into the cast iron plumbing from the toilet. Its smaller in diameter, so its not sealed. is just hovers in the cast iron, nice smell under the house.... :huh:


Thats my biggest question... How do I connect into that cast iron with new pvc???


Thanks for all the help. This house is really screwed up. ill say I added a trap to the bath tub today. its just as bad as this is. the tub has like 1 1/2" pvc going into a 2" pvc pipe just like pictured above. not sealed. going into the same type of black abs? like 4" id guess drain.... and whoever decided to run a 2" piece of pvc into a 4" drain decided using Masonary patch would be a awesome way of connecting them! :bangin: Can't make this stuff up.
 
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#2 ·
If that was mine I'd be removing and replacing all if that old steel and cast iron with new PVC or ABS.
It is going to leak and plug up on the insides at some point if it's not already.
They do make a donut shaped gasket to convert that hub to a new piece of PVC, but you still would have all that other mess to deal with.
 
#4 · (Edited)
Thanks for the reply. I didn't pay much attention as to what the iron pipes going into that hub. I'd guess vents? Ill have to get under there and look at it all again. And again I'm no plumber so I'm not sure if I would be capable to replacing all that old iron pipe, especially If it is vents and goes up through the walls???

If I started replacing it, but I could no longer go farther with it, is there a simplier product to connect (I'm guessing that's 1 1/2" iron pipe) 1 1/2" iron to 1 1/2" PVC?

All that's doesn't sound as bad as I thought though.

What's a lav?


Edit- actually, I think that's not a vent but the drain for the sink. The sink is actually to the right in the picture, but the pipe also goes left.,, not sure why..... Nothing is there, unless its a hold drain for the bathtub that's no longer used...
 
#7 · (Edited)
Replace all the way down to abs.:thumbsup: A plumber would knock it out in 1 hour or mine would. Its not a bad job for a experience plumbers.

Ps. I bet the toliet to cast iron is old school rope sealing the connection. I forget what its called. They actually used rope back in the day to seal connections like this.
 
#8 ·
Fall....don't be afraid of it....it really is a lot easier than it looks once you get past the stigma of working with cast iron pipe....I did something similar.....Once you cut that pipe with your sawzall....it gets easy after that....hard part is crawling on your back in the crawl space....
 
#9 ·
The more I look at it, plus the info I got here, I'm not too worried. I got back under the house to check out the lines going into that cast hub. Like I figured the pipe going to the left in the picture is a old drain pipe that is sealed off now for the tub. The line going "behind" the hub goes up into the wall, has to be a vent. The sink has its own drain and doesn't tie into what's pictured.

Only question I believe I now have is what will be the best way to connect abs into the cast iron vent? the cast iron is threaded, naturally, at the 90 bend, could I just unscrew it (if possible) and find a piece of abs that's threaded for it? Or would I be best to use one of those rubber connectors with clamps?
 
#11 ·
What I am looking at is out of the picture above. It has to be the vent, nothing else it could be, the pipe goes from that hub, to the tee, then straight back then 90s up the wall, that's what I am talking about. (At the tee is where the now capped off old drain for the bath tub comes in).

I have pictures, but I can't post them from the phone, I found this online which is what my pipes look like, only nicer.




I was doubting they would unscrew. So what would be my easiest bet, taking a sawsall to the piece of straight pipe coming off the hub after the tee and before the 90 and just add abs and use one of those rubber couplers like this?



If I got that right, seems like a cake walk, only thing I can't ask is any cool tricks to cutting the soon to be new abs toilet pipe flush with the floor?
 
#13 ·
Okay boys, thanks to your help I nearly got it done, well the plumbing is, I just have to put the new floor in, had to stop to attend a wedding.

Anyways, the vent pipe was full of nasty junk and rust. But I think I cleared it out. The real problem I ran into... That 4" abs, apperantly is a much smaller diameter 4". I put a 4" coupler on it and it just slid down. I had no idea what I could do, other than using a big rubber coupler, that I didn't have on hand, so I slathered it in abs cement and added the new piece to hold it there to seal.

Nothing ever goes right, what was the correct way to do that? The rubber coupler or a special plastic coupler?

Ill post pictures of my work once I'm done and can get on the computer to size em down.
 
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