Flange-free Toilet Install

Just pulled up my leaky basement toilet, and it is not clear to me if it was originally installed correctly. I have a 3" PVC drain pipe cut flush to the floor (vinyl on concrete). There is no flange on the PVC, here is a picture:

On the bottom of the toilet was a wax seal. In the center of the wax seal the toilet necks down but obviously doesn't seal with the drain. The toilet setup is pictured here:

I am assuming the intent was to seal both the toilet neck and the drain so that the waste water worked it's way down the drain. But I think what happens is the water is seeping through the crack in the vinyl that can be seen in the first picture.

My question is; was this properly installed? I am assuming it wasn't since it leaks. If it wasn't properly installed, do I need to install flange to the drain pipe?

TIA

Wow...

You ABSOLUTELY need a flange.

You might need an inside-pipe-cutter to trim some pipe.

You certainly need a flange, that's why it was leaking. A flange also holds the toilet in position which keeps the toilet from moving and that keeps the wax seal intact. If the pipe is 4" PVC, you can use a flange that fits inside the pipe. They make the same type of flange for 3" pipe, but we do not recommend them as that cuts the inside diameter of the pipe too much. In that case you will likely have to chip out some concrete and shorten the pipe with the inside cutter. No matter what flange you end up installing, make certain it is oriented so that the flange bolts will line up with the holes in the toilet, the flange is resting on top of the finished floor, and is secured to the floor with screws. On concrete there are two or three ways to do this. My favorite way is to drill holes for lead sleeves then use #12 stainless steel sheet metal screws. Drilling is easy with a rotary hammer drill. Use at least 4 screws spaced around the flange rim.

Going to try the 3" insert because the toilet doesn't get a lot of use. If that becomes a problem, I will just have a professional come out and install a normal flange.

Thanks for the help guys.

PlumbingNovice said:

Going to try the 3" insert because the toilet doesn't get a lot of use. If that becomes a problem, I will just have a professional come out and install a normal flange.

Thanks for the help guys.

Click to expand...

Once you glue the lazy style flange in there it will be a big pain to install the proper flange later, don't do it.

The 3" insert flange WILL "become the problem", if you need to have a plumber change it in the future. Take some time to remove some concrete and install the right flange. The groove in the vinyl was NOT the cause of any leak, because the wax seal would have conformed to the floor. How was the toilet secured? By closet screws into the floor, or how? I don't know what you mean by "obviously did not seal with the drain", because the wax ring WAS deformed when it was squeezed between the toilet and the floor.

Sometimes there are more than one way to do an acceptable job. This isn't one of them. Yes, you can put that inside fitting flange in the pipe and will work...for awhile. This is a time where Murhpy's Law applies. "Whatever can go wrong will at the most inconvenient time possible." It's understandable that you just want to get this job done because time is short before Christmas, etc., etc.. But, it will take more time and work later and will almost certainly require a plumber and a lot more concrete chipping. Sadly, there are several plumbing products one can buy that should not be allowed to be sold. An inside fitting 3" toilet flange is one of these.

It has nothing to do with Murphy's Law, it has to do with "easy-way-out renovations"...

Well, we might debate the difference, but whatever. Bottom line is this is a bad idea.

Gary Swart said:

Well, we might debate the difference, but whatever. Bottom line is this is a bad idea.

Click to expand...

I haven't installed anything so I have time to make any changes I need to.

If I want to put in a regular 3" flange does it fit directly on top of the old pipe that I cut down? I ask because I would need to glue the new flange to the old PVC, right? So can I glue two pieces of PVC end to end? I thought they needed to overlap, or do I have to chip out the concert so the new flange fits on the outside of the 3" drain pipe?

Out of curiosity what is so bad about the inside fitting flange on a 3" drain pipe? I was assuming it was because it necks down to such a small diameter ~2.75", but that is the same diameter of the hole in the bottom of the toilet, so what makes it such a potential problem?

PVC pipe is about 1/4" thick, so your 3" pipe now becomes a 2.5" pipe...not good! Some of the better toilets have over a 2" outlet, then add the thickness of the porcelain horn, and the toilet may not sit flat because it is being held up since it can't fit down into the hole. The Caroma's have a 3" outlet. You never want to make the waste go through a narrowing section...it promotes clogs.

The reason you'd need to chip out some concrete is a normal 3" flange would fit around the pipe, not butt up to it...you need room all the way around and the depth of the socket on the end of the flange to fit down over the outside of the pipe. And, you need enough room to brush on some cleaner then the cement on the pipe. You may need to trim the pipe stub a little bit, since many flanges have a lip on the inside that acts like a stop and to get it to fit down all the way, the top of the pipe must be lower. I think a spicot flange may fit, as I don't think it has that stop...the pipe would come up the middle and you'd then cut it off flush with the top of the flange, if needed. This type doesn't have the tapered socket, so it doesn't fit as tight - make sure you get a good even coat of cement.

Just to carry Jim's point a step further. If you remember your HS math, you will remember that formula to find the area of a circle is PI x Radius squared. The radius of a 3" pipe is 1.5". The square of 1.5" is 2.25" and when we multiply by 3.14, that gives us an area of 2.25 square inches. When that pipe is reduced by .25", the radius is now 1.25" The square of 1.25" and when multiplied by 3.14, we have an area of 1.56 square inches. So you can that a great deal of area is lost by using that 1/4" thick flange.

I would be tempted to rent a tool (big driver/drill? electric jackhammer?) and excavate a good foot or more diameter hole to do the steps Jim describes above. It will make life easier for you, and not a big deal to buy some concrete mix and patch up a hole that size. You then have the luxury of good access to the outside of the pipe, and can cut it however you need to, get primer and cement on it, etc.

actually, a small hammer drill will work quite well. You can drill holes and/or chisel with them and they are not difficult to control. You're not going to demo the entire floor, just clear some space around the pipe.