View Full Version : Flange replacement in concrete floor advice
09-21-2007, 10:26 AM
Just removed an old toilet from the concrete floor in the basement and have found the following:
-3 inch inside diameter cast iron pipe
Need advice on what kind of flange kit and mounting bolts are reccomended in this situation. I've read on other posts that PVC isn't recommended because it doesn't glue well to cast iron.
Thanks in advance
09-21-2007, 11:28 AM
There's a PVC flange with an extension that has a rubber seal that flares out when you tighten a few allen screws. If the CI pipe is in good shape, it should make an effective seal.
You could also hire a plumber to lead and oakum on a new CI flange.
Use a grinder to grind down or cut off the old bolts.
09-21-2007, 11:32 AM
Sometimes I rotohammer a flange in like this to hold the closet bolts.
09-21-2007, 11:38 AM
Terry, wouldn't you need to use that sort of flange in combination with a waxless in order to get an effective seal with the CI pipe?
09-21-2007, 12:53 PM
Wax does a pretty good job.
It's what they've had for.........looks pretty old to me.
Sometimes the plastic flanges that sit on top, are too high for the toilets.
Then I have to shim the bowl where it doesn't meet the floor.
The metal repair ring is flat. The bowl sets right over it.
09-21-2007, 11:10 PM
I know that wax will make a seal between the bowl and the ring, but how does the ring seal tight against that old cast iron pipe?
09-22-2007, 01:47 PM
When you put a repair ring on, it's a good idea to use some silicon before you screw it in place. You could use some urethane as well. The better ones are guaranteed for 50-years or so.
09-22-2007, 02:21 PM
From that photo, it looks like the concrete surface is not even. So, when he goes to screw in the ring, there will be some gaps. I guess he'll need a lot of silicone. Or will the wax squish down to fill the gaps?
Do they sell a rubber gasket to use under the ring in this instance?
09-22-2007, 08:08 PM
The metal ring is only to hold standard closet bolts.
Or you could put threaded inserts in the concrete and use threaded bolts.
You will notice that most flanges swivel around a hub, have slots, holes and notches.
If you can find an insert flange like the one Verdeboy shows, without raising the bowl, then that would work too.
I don't worry about all those slots, holes and slide fittings.
As long as the bolts can be held firm, then the toilet will be held to the floor tightly.
If the bowl doesn't move, the wax should stay sealed. There are little bees making the wax. For the most part, they do a pretty good job of it. Sticky wax seals pretty well.
This is one of my busy bees, always busy making wax for me.
I use quit a bit, so I keep them very busy.
09-24-2007, 09:32 AM
Think I'll go with the metal flange plan. The floor is uneven so I'll have to pour concrete anyway for a flat surface for the bowl. Is it possible to set the metal flange in concrete?
Any then fill in any gaps with silicone.
Over the weekend I tried to get one of the self tightening plastic flanges but nobody had them. They were only available for a 4 inch CI pipe, not a 3 inch pipe.
09-26-2007, 10:06 AM
There's a PVC flange with an extension that has a rubber seal that flares out when you tighten a few allen screws. If the CI pipe is in good shape, it should make an effective seal.Oatey also makes a CI version of the same "Twist N Fit" flange extender. Just saw it the other day at Home Depot.
09-26-2007, 11:12 AM
Oatey also makes a CI version of the same "Twist N Fit" flange extender. Just saw it the other day at Home Depot.
Thanks, but I'm not taking any advice from Indians' fans today. ;)
10-10-2007, 01:42 PM
ok, got the job done today. So far so good with no leaks.
I chipped away at the old concrete and found and old CI flange embedded in the concrete. Then I cleaned up the flange and drilled out the two old bolts and drilled down into the concrete below the flange.
After that I poured a level concrete platform at about the same height as the flange, on with the wax seal and held the bowl in place with two tapcon screws which go through the flange and into the concrete below.
No leaks so far!