View Full Version : Do I need a plumber? Re: Flange

03-10-2010, 03:49 PM

I recently bought a house and I've found myself in a little over my head during a bathroom remodeling and wanted to get some opinions from people who knew a bit more than I do.

I first removed the old toilet (and vanity). Beneath the old toilet there was an old flange installed which I removed. I believe it was plastic but I could be wrong. It was one like this with holes on the outside of the ring.

However, it either had another piece attached or it was one of the ones that isn't just the ring, but also has a bit of a tube attached that goes down into the pipe, sort of like this:

After I removed the toilet and that flange I had a new subfloor put in by a contractor. He advised me to simply install a new plastic flange and then install the toilet.

However, it seems he may have cut the hole a bit wider than he should have. He cut it to 7.75" in diameter.

Also, I showed the pictures below to a guy at Lowes who is supposedly a plumber, and he seemed to think that doing it that way wouldn't work for some reason, even though the toilet worked fine before. He said that it looks like there is an old cast iron flange on there that has to be removed and replaced, and therefore I'd need to call in a plumber who will have to cut out part of the new subfloor, use special tools to heat/remove the old flange (if it's done wrong, he said, something could explode?), and replace it, and then fix the subfloor. However, he had an arrogant attitude and didn't make it very clear why he felt using a plastic flange wouldn't work, so I'm not going to just take his word for it and waste money if I don't have to without getting other opinions.

He did raise the issue of the size of the hole, which does seem problematic, but I was thinking that perhaps there was a wider flange I could use that would fit. The old flange that I removed, with the holes on the outside of the ring as shown in the image above, are about 7.25" apart, so it's only about maybe an inch too small.

As I said I'm no expert on this which is why I'm here. Any input would be appreciated. If you need any other info let me know.


I'm limited to 4 embedded images so here are links to 3 more:

03-10-2010, 05:49 PM
What you have there is a cast iron toilet flange. If you wanted to do this right, you would have removed that flange, then installed a new one once the finished floor was installed as the flange is designed to fit on TOP of the FINISHED floor. You'll need to take those old bolts out and install some new ones. Your choices are: tear out that flange, have a new one installed on top of the floor (which should have come close to the pipe so you could tile under it), add some flange extenders to what you have to raise the height, maybe install an internal mount CI flange inside of the pipe (from your measurements, it appears to be a 4" pipe - internal is okay for them but not for a 3" pipe), use a waxless seal to accomodate the recessed flange. On some toilets, that large hole will show underneath the toilet!

Some of those choices would require redoing the subfloor, as you need something to anchor things to. An all CI flange, leaded in place, is strong enough to sit there in the air without anchoring it to the floor as well. It would be stronger if you could anchor it to the floor.

How far is the center of the flange to the finished wall? If it is far off of 12", you might want to have that part redone so your choice of toilets is decent.

Do you have any access from underneath? That would open up some patching possibilities.

03-10-2010, 10:40 PM
Thanks a lot for the response jadnashua.

I'll have to measure the distance but I want to say it's roughly 13 inches. I could be off on that.

I do have access from underneath, yes.

Someone recommended a "pvc twist n set" which I guess is this:
http://www.oatey.com/Channel/Shared/ProductGroupDetail/363/Twist_N_Set__Cast_Iron_Replacement_Closet_Flange.h tml

Does that sound like a reasonable solution?
If so, what would need to be done to prepare and install it, and is it something I as a layman can do? (I'm guessing at the very least the old bolts have to be taken out as you said - not sure if I can just do that like normal or if there is something else I need to know). If I got a pro to do it do you have any idea what I might expect to pay?

03-11-2010, 09:44 AM
The twist and set flange makes a seal by compressing a gasket on the inside of the pipe...if you look at yours, would you want to rely on that to seal out gas and water if there was a backup? It can work if the pipe isn't in too bad a condition.

I think what I'd do is probably cut out part of the cast iron from below, then transition to PVC or ABS (whichever is more common in your area). I'd also patch the subflooring by maybe putting in some bridging and either fill in or replace a square around the toilet so you could then support the new flange properly once installed.

An older pro would probably replace the existing CI flange with a new one at the proper height. This is a dying art. So, a younger guy may transition to plastic.

You'd need a picture of the piping below to determine the best place to cut. it depends on how much of a straight piece you have and where the nearest hub connection is the best way to make the transition.

Any flange, other than a new CI one, needs to be anchored to the subflooring. WIthout fixing that, there's nothing to hold the toilet in place. The leaded connection between the CI pipe and a CI flange is generally strong enough to not require connection to the subfloor - it doesn't hurt, but it may not be absolutely necessary. Keep in mind that it is the flange that is holding the toilet in place, and if that flange is just sitting in there with a gasket (like the twist-and-set) or a piece of plastic, you'll have problems.

03-11-2010, 01:44 PM
(deleted by myself, duplicate post)

03-11-2010, 01:45 PM
Thanks again jadnashua.

Here are some pictures from below which I think give a much better idea of what's going on.


03-11-2010, 01:46 PM
This is the old flange which had been rigged to sit on top of the cast iron one seen above. I think it is metal too.


Here is what it looks like just sitting over top of the hole and the cast iron flange. As you can see the hole in the subfloor is a bit too big to screw this particular flange down as I said earlier.


03-11-2010, 02:52 PM
Whatever you end up doing, you'll want to reinforce that floor. They didn't do you any favors when they cut almost all of that joist away. Especially if you are going to add tile, that joist is doing nothing and your tile will be severely at risk.

WIth the multiple connections there, I think I'd call in a pro and have him install a new CI flange at the proper height.

WHat you had there was a repair ring, and it needed to be attached to the subfloor.

Dunbar Plumbing
03-11-2010, 09:48 PM
You got a horrible mess right there.

That subfloor is destroyed being cut out that far.

Cut out the cast iron, replace the floor, drill a new hole to tolerance on the new flange and get the installation back to industry standard.

Gary Swart
03-11-2010, 10:33 PM
Considering that you have no experience with plumbing a toilet drain, amd the terrible condition of the floor and pipes you are working with, I would get a pro to do this. This is too much for a novice to tackle. We DIYer need to know our limitations and when it is time to seek professional help.

03-12-2010, 08:30 AM
actually, you have gotten the best advice elsewhere, and should follow it. Are you posting on multiple forums hoping for an answer that agrees with you?

03-12-2010, 04:58 PM
Thanks Dunbar and Gary, and thanks again jadnashua.

actually, you have gotten the best advice elsewhere, and should follow it. Are you posting on multiple forums hoping for an answer that agrees with you?

No. What would be the point of that? If I had a strong opinion on this matter and didn't want to listen to honest advice I wouldn't have taken the time to solicit honest advice. I searched the internet for a good plumbing forum and found two that looked promising: this one and p***. I composed a thread on this forum and posted it. I then (within minutes) posted the same thread to the other one, not knowing where I would get a higher quantity or quality of response. Judging from the helpful answers I got on both forums I am now quite sure that I need a plumber.

So again, the answer to your accusatory question is no.