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View Full Version : Installing a flange on an old mangled lead bend in a concrete floor


Vicente501
Mar 18, 2014, 10:57 PM
I'm a novice. I started a simple task of replacing a toilet in a 1960s one-story house built on a concrete slab. I had to change the flange because the old bolts had been run through holes and not the slots, making it impossible to use the flange where it was, since the bolt slots did not align. I mistakenly thought the flange was cast iron and tried to remove it pursuant to some video instructions I saw on YouTube. After trying to chisel it and banging it up I realized it was brass with a lead bend which had been lipped over the inside of the flange. I was at a point of no return and the flange had to come out so I chiseled the lead away from the lip of the flange. I now have a lead bend with a misshaped and ragged lip that extends up from 1/4" to 1/2 inch above the concrete. Moreover, the bend is not perfectly round down the neck so it doesn't look like any sort of extender will slide into it without it being reshaped. Since this is a concrete floor I have little room to maneuver. Can I salvage this project and install a flange or have I flubbed it?

speedball1
Mar 19, 2014, 05:11 AM
Your best solution would be to break open the slab all the way back to where the lead bend connects into the cast iron pipe and , using a No-Hub Band, convert to PVC. You may then patch the floor and install your toilet. Good luck, Tom

Vicente501
Mar 19, 2014, 09:04 AM
Thanks for your reply Tom. I'm sure that's the best solution but breaking open the slab would likely involve tearing up a wall as well as the reinforced concrete and that is beyond my capabilities. Is there any other workable solution?

speedball1
Mar 19, 2014, 12:23 PM
Is there any other workable solution? That depends on how much of the lead closet bend you left. If you have left enough to form a 1/2 or 3/4" lip on the floor I believe we have a solution. If not we're back to solution one. Let me know. Tom

Vicente501
Mar 20, 2014, 02:29 PM
Hi Tom
Due to time constraints I bit the bullet and hired a plumber who installed a new brass flange, probably in the same manner you would have suggested. There was enough lip for him to solder the lead bend to the new flange. It took him about 20 minutes. The cost of parts and labor was worth the time and anguish it would have cost me.
He told me that I could have heated the old flange, not the lead itself, to soften the soldered lip and spun the flange so that the key slots aligned in order to put in new closet bolts and then tapped the solder back down. Do you concur with this? I would like to know because I have another toilet, same house, that no doubt has the same brass flange/lead bend installation.

Thanks, Vicente

speedball1
Mar 20, 2014, 02:44 PM
I agree with the plumber. However, This is like wiping a lead joint, Too much heat and the lead and the lead melts If you try this be very careful. Good luck, Tom