Copper toilet flange into cast iron pipe issue

Discussion in 'Toilet Forum discussions' started by spta97, Dec 1, 2009.

  1. spta97

    spta97 New Member

    Messages:
    68
    Location:
    New York
    Hi everyone! I'm new to the forum and was hoping to get some advice on what appears to be a unique setup.

    I have a cast iron waste pipe but the flange is copper (house is built in the 1950's). I recently put down the new tile floor and the underlayment was thinner than the old mud floor that was there so I have too much pipe sticking out of the floor now:

    [​IMG]

    I had a plumber (it was actually two guys) over today to cut the pipe and solder on the new flange but they said it was too much work. Instead, they suggested cutting the pipe below the floor and using a Fernco fitting to PVC (and quoted me $650). I've never been crazy about using them because I was told that eventually they will leak.

    They also said that it looked like I had a leak at the joint where the copper pipe meets the cast iron stack. To resolve that (if it did leak) they said they would use a 4" to 3" doughnut and then do PVC all the way up to the flange at a cost of $1000 :eek:

    I did not have any water damage on the drywall that was covering it and I just ran about 10 gallons of water from a hose down it and it was dry, although it looks like there is some serious corrosion (dissimilar metals perhaps?):

    [​IMG]

    I had sugguested to the plumbers that they use an inside pipe cutter but they said that they always fall off the drill and into the pipe.
    So my questions:

    1) Should I be worried about a leak at the joint on the cast iron?
    2) Can I just use an inside pipe cutter and cut the pipe sticking out of the floor? I was thinking of duct taping the bit to the drill so if it comes loose out of the chuck it won't fall in the pipe.

    Any advice you can offer is greatly appreciated as I don't think I can bring myself to spend that kind of money on this as it greatly exceeds my budget. I can solder pipes (I plumbed the rest of the bathroom) but I figured this job was best left to the pros but after getting the sticker shock I'm thinking I should take a crack at it.


    Here is a picture of the copper flange I got for $40. As you can see it just needs a couple of inches trimmed off the top:

    [​IMG]

    Thanks!
  2. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    21,889
    Location:
    New England
    I'm not a pro, but my first thought is it will take quite a bit of heat to melt solder on that thing! I'd be worried about too much heat, and you probably don't have a torch big enough.

    I think if I was going to do it, I'd remove the copper and do as they indicated - use a donut and replace the stuff with pvc. If you cut the copper off near the cast iron hub, you could probably rip that joint out of there. The pros may have some suggestions. With cast iron, (I've only done a couple), I used a drill to make swiss cheese out of the lead, then pryed out the lead. With the copper, you could probably use a hack saw or sawsall to cut through the copper from the inside and some of the lead, and fairly easily remove the whole thing, especially if you made two cuts and pryed out a chunk. The lead will stick to the copper, but it will come right off the CI. Then, a wire brush to clean it off and maybe a little dish soap on the donut, and you press in the pvc stub, and glue up the elbow, and riser, and you're ready to install the flange. Get one with a SS ring, and you will need to drill some holes in the tile to anchor it to the subfloor. This may require a diamond bit. Lowes carries some. Get one the right size for the anchor you use, or if you can catch the plywood, ensure the hole is big enough so the screw doesn't catch or you'll crack a tile.

    You could probably have the whole thing out of there in 1/2-hour, and, new stuff inserted in another 1/2-hour, depending on access and the skill of the operator. It'll probably take longer to drill holes through the tile to anchor the flange.

    Again, I'm not a pro, but my guess is it shouldn't take more than 2-hours labor, so at $1000, unless they're doing other things or you live way out in the boonies, seems a little high. Could be normal, different locales have different rates to account for different cost of living.

    Parts to do this are probably less than $25 - less than you paid for the copper flange. And, you could recycle the copper you take out. It's proably at least a couple $/pound.
  3. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,485
    Location:
    Cave Creek, Arizona
    flange

    I would just solder a new brass flange to the copper, (it would only take a few minutes), and the cut the pipe to fit with a SawZall. I am not sure what is under that mass of cement, or whatever it is, but if there is any lead there, then it should be able to be resealed. Anything else, and it is a bad installation and should have been fixed BEFORE the floor was tiled.
  4. spta97

    spta97 New Member

    Messages:
    68
    Location:
    New York

    jadnashua - Thanks for your reply. You can't see it in the picture because the flange is not aligned as it would be at install but I do have the holes drilled in the tile for the screws already there. I'm aprehensive to mess with the the joint to the cast iron stack if it is not leaking. I ran gallons of water through it last night without an issue but I will poke around the lead this weekend to see if it is strong. I am tempted to replace the whole thing with PVC but my only concern is a doughnut may have an issue. I am fairly confident I can get the pipe out with a sawsall and my mapp torch but I am less confident in my ability to get the doughnut in there making a proper seal.

    My friend said I should not be afraid of the rubber failing and said his house has all his PVC connected via a rubber boot to a cast iron pipe. He went on to say that the plumbers used some kind of liquid rubber that hardend to make a nice seal.

    I am tempted to try and cut the pipe and solder on the copper flange...
  5. spta97

    spta97 New Member

    Messages:
    68
    Location:
    New York
    hj - Thanks for the reply. The issue with cutting the pipe is that it is hard to get a sawsall at that angle as I would have to have the blade almost flush with the floor. If they made a pull saw for copper that would do the trick. Also, they have brass flanges? Is that better than the copper one I have?

    So do you think that the joint to the cast iron is leaking? I would have addressed it but there has been no leaks and the drywall that was covering it was dry so I figured it was just a result of the copper to cast iron joint.


    Thanks..
  6. FloridaOrange

    FloridaOrange Plumbing Designer

    Messages:
    1,317
    Location:
    SW Florida
    You could use a dremmel or rotary cutter with a wheel.
  7. spta97

    spta97 New Member

    Messages:
    68
    Location:
    New York
    The plumber borrowed my Rotozip with the cutting wheel but we realized that it would not sit low enough. I will take a look at it too see if I can take the guard off so I can get it flush. Although I could perhaps do that from the bottom and rest the Rotozip on the bottom of the floor....

    Thanks for the idea.
  8. FloridaOrange

    FloridaOrange Plumbing Designer

    Messages:
    1,317
    Location:
    SW Florida
    Cut from inside the pipe....unless I'm missing something or maybe the Rotozip won't fit. My dremmel would fit
  9. spta97

    spta97 New Member

    Messages:
    68
    Location:
    New York
    I'm pretty sure that I won't be able to get a strait cut using a dremmel and one of the cut off wheels. Any tricks to doing so?

    Thanks..
  10. FloridaOrange

    FloridaOrange Plumbing Designer

    Messages:
    1,317
    Location:
    SW Florida
    Go slow. :D I haven't had to cut off pipe yet so no tricks, sorry. I have cut alot of other stuff, even thick mounting brackets (much harder than copper) just not pipe from the inside.
  11. spta97

    spta97 New Member

    Messages:
    68
    Location:
    New York
    The problem with the Dremmel is that it really gets away from you. Not to mention you go through a billion cut off wheels per job ;)

    Although I may be able to cut it from the outside that way if I just wanted to get the pipe lower than the floor level. Ideally I want to cut it to the right height so it is sitting at the bottom of the flange.

    I figure I will take a crack at cutting the pipe from below (if that's even possible) or from above before I replace the whole thing.
  12. FloridaOrange

    FloridaOrange Plumbing Designer

    Messages:
    1,317
    Location:
    SW Florida
    I've had decent results with scoring the cut first, then if the dremmel does jump it has a guide.
  13. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,485
    Location:
    Cave Creek, Arizona
    cut

    You DO NOT cut "through" the pipe. You cut off the top of it by moving the saw around the pipe as you cut it off.
  14. spta97

    spta97 New Member

    Messages:
    68
    Location:
    New York
    Thanks for the input. I am going to do exactly that - take the guard off my 3" cut off wheel for the flange pipe and poke around the corosion at the joint first. My friend said that he does the "ice pick test". Meaning if you are able to poke a hole through the lead it would eventualy leak.
  15. spta97

    spta97 New Member

    Messages:
    68
    Location:
    New York
    hj - I think I know what you are saying but can you clarify? My intent would be to run the cutter around the outside of the pipe to create a slit and then move the cutter around the outside to cut the top off. Is that what you are referring to?

    The other option I am going to explore is seeing how low the flange sits in the floor and seeing if I can get a blade flush with the sub floor and cut it from underneath- provided that is where the pipe should be cut. The flange I have is a few inches deep and appears to sit below the sub floor when installed (1/4" tile, 1/4" thinset, 1/8" Ditra, 3/4" plywood = 1 3/8" total).
    Last edited: Dec 3, 2009
  16. shacko

    shacko Master Plumber-Gas Fitter

    Messages:
    561
    Location:
    Rosedale, Md
    It may be my eyes but, that flange looks like it is the wrong size for the pipe, and what you show on the underside doesn't compute at all??
  17. spta97

    spta97 New Member

    Messages:
    68
    Location:
    New York
    It is a 3" flange that fits on the 3" pipe. It fits on the outside of the pipe - does that make sense?
  18. ChuckS

    ChuckS New Member

    Messages:
    96
    Location:
    Aurora, CO
    I'm no plumber but it seems to me you may not have to cut the excess completely off.

    If you cut vertical slits in the pipe about every 1/4 inch you can then fold the tabs down into the pipe. You could break them off if you want but the flange will be inside so they may be ok just folded down.
  19. spta97

    spta97 New Member

    Messages:
    68
    Location:
    New York
    Thanks for the idea, I'm not crazy about blocking the inside of the pipe. I didn't get to address the plumbing this weekend but perhaps next.
  20. spta97

    spta97 New Member

    Messages:
    68
    Location:
    New York
    Done!

    Hey guys. Just wanted to thank you for the advice. I tried to get my Rotozip in to cut the pipe but it was just too big so I went with the Dremmel and a "heavy duty" :rolleyes: cut off disk.

    Unfortunately I didn't leave enough room on the outside of the pipe so I ended cutting it from the inside. After about 10 broken cut off disks I got the pipe off! Suprisingly I did a pretty good job as it is just about 1/8" high in one place but I didn't want to push my luck. I grinded the edges smooth then went to town with sand paper to clean up the outside of the pipe.

    I used my MAPP torch to solder it which took a little bit to get it hot enough but it seems to have made a nice seal. After it cooled I ran the shower head over the joint for about 5 minutes and no leaks to speak of :D

    One trick that my friend taught me was to use a heat sink on the pipe. I had a joint only about 4" from where I was sweating the flange so I took a big C-clamp and clamped it right under - and man did it get hot! Everyone here probably knows this trick but it works great with a vice grip on smaller pipes when you have joints that are close together and you don't want to melt them - the clamp absorbs the heat so it won't get the joint below it hot enough to melt.

    Anyway, not terribly pretty but not leaking! Thanks!:

    [​IMG]
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