View Full Version : How do I Install A Toilet Flange on a cast iron Soil pipe in the basement

01-08-2005, 06:01 PM
Hi all, Im trying to finish off what looks to be a roughed in bath room off my laundry room in my garden level basement. There is a 4" cast iron soil pipe sticking up 2" from the cement floor pluged with cement that I would like to attach a toilet flange to with out having to chip out the cement around it if I can. Any ideas? The center of the soil pipe will be about 12" from the finished wall, will that be a problem? Any feedback would be very welcome!! Thanks all!!!

01-08-2005, 08:18 PM
The 12" from a finished wall will let you use practically any toilet, as that is the standard in the USA. I've never attached a flange to cast iron (I'm not a pro), but my guess is that there are probably internal clamping flanges. In the "old" days, my guess is that they would use oakem and lead, but there are easier ways today.

01-09-2005, 06:49 AM
Thanks Jim, I guess I'll head down to the local plumbing store and ask if they have an internal flange. Wish me luck! Oh and do you have any Ideas about cutting down the soil pipe? It's cast iron so I dont think my SawsAll will work to good?
Thanks Again!!

01-09-2005, 10:40 AM
"...Im trying to finish off what looks to be a roughed in bath room off my laundry room in my garden level basement..."
I think that it might be a good idea to determine if this is really a stub out for a toilet--it could have been meant to be something like a floor drain. The 12" from the wall is the standard rough-in for a WC, so it probably is, but you cannot arbitrarily plop a toilet down on a convenient drain pipe sticking up out of the floor. Is this vented? Correctly? Make sure that there is not a p-trap on this line.
The Pipewench

01-11-2005, 01:30 PM
You need to put in your finished floor first. Since the flange needs to sit on the floor. So put in your tile linoleum etc then put one of these flanges (http://www.oatey.com/apps/catalog/showskus.asp?ctg=11&subctg=3&prodgrpid=106) and attach it to the floor using some sort of concrete fastener like a lag bolt, or Red Head, or Fastcon, concrete fastener. You'll need to test fit the flange and mark the location of the holes for whatever fastener you use. Then drill out the holes and if you use lags put them in the holes. Then put the flange in and install the fasteners and tighten/seal the flange.
That's what this DIY'er did in my basement bathroom. Oh by the way you'll need to cut that pipe down to be flush w/ the finished floor. I used a grinder and cut it off, pipe snappers just can't get that low on a floor.

01-15-2005, 03:43 PM
Hi guys and gals, sorry I took so long to get back to you all. I wanted to make sure the soil pipe was for a toilet like Deb suggested. I talked to an old timer in the neighborhood and he stated that that room was an option to be a finished bath or left as a roughed in one so I guess Iím ok. I just finished framing out the back wall, ceiling and roughing in the copper pipe for the sink and toilet. Iím not going to do a shower or bath. Iím not up to breaking up the concrete to tie in the drain pipe. Thanks for the heads up on the soil pipe JD, I was going to cut it, set the flange and then tile up to it. Now Iíll wait till after I tile.
Thanks again all

01-16-2005, 08:12 AM
Don't use those inside closet flanges, what you need to use on cast is what they call an inst-set flange, the gasket is sealed on the outside of the pipe not the inside, it will have 4 top blots that will allow this flanges gasket to squeeze tight against the pipe, you will need to go to a plumbing supply house to get this flange.

01-19-2005, 12:41 PM
For what it's worth and I'm not a professional:
A lot of plumbers don't like to use the PVC flange that goes inside the pipe but many do use them or know plumbers that do. The cast iron one that goes on the outside probably is better/stronger but if you don't want to remove the concrete around the pipe the inside PVC retrofit is a good option in my opinion. Also, I had to buy the ones I used at a plumging supply house, the big boxes didn't carry them.

Also if you're installing ceramic tile consider how you'll drill through the tile for the flange hold down screws. I just notched the tile w/ the tile saw where the screws were anticpated to penetrate the tile. But maybe drilling through tile is not that difficult.