Help! Leak around toilet base

Just replaced an aging toilet in my basement with a Toto Drake. After a few days of "use" I noticed a small amount of water along the side of the toilet that sits on the bare concrete basement floor. A little background first, the old toilet was fastenened to the floor using two bolts which screwed into the concrete, no flange was used, it never leaked. It sat on a ~4" cast iron waste pipe that was not flush to the floor but rather was above the floor surface 1/2" to 5/8". I was told to grind the waste pipe to at least 1/4" before putting the new Toto in, which I did. I put a single wax ring on (with the plastic flange), put a bead of caulk around the back end of the Toto and lowered it onto the waste pipe opening and bolted it to the floor. It was fine for 4-5 days until yesterday when I noticed the water at the base. My question to all of you fine folks is there a leak because: I should have ground the waste pipe flush to the basement floor rather than leaving a 1/4" lip above the surface; didn't use a thicker,larger wax ring that was available; maybe I didn't center the Toto into the waste pipe correctly before securing it to the floor??? Obviously I am a weekend plumber and I really would appreciate any advice you can give me. Also sorry for the long thread.

leak

It could be any of the above, or it could be because you did not install a flange first, which is what a plumber would have done if he had installed the toilet. And are you sure the leak is not occurring where the tank sits on the bowl and is running down the back of the toilet to the floor?

leak

What are the closet bolts attached too.........Or are you using closet screws?

I checked all around the tank and sides of the toilet bowl with my hand and it's dry. The toilet is simply attached to the concrete floor with the use of two 1/4" stainless steel bolts and washers, one for each side of the toilet. The bolts are then screwed into the concrete until snug.

I think it's likely the old toilet didn't leak because the drain pipe protruded into the horn on the base of the toilet and with the wax ring fit around it and with the toilet anchored firmly to the concrete floor so it didn't rock, you had a connection that functioned very much like a modern flange. When you cut the protuding drain pipe down, you lost that part of the connection. You need to install a flange that fits inside the drainpipe and screw it down to the concrete. There are several ways to anchor things to concrete, but my favorite method is to use the flange as a pattern and drill holes for lead farrells. Then I use stainless steel sheet metal screws into the farrells.

Gary, before I did anything with the waste pipe (after I took the old toilet off) I put the new Toto on just to see how it would fit. As it turned out the pipe inself was to high and the Toto actually sat on top of the pipe never touching the floor. This is why I used a grinder to knock it down to about a 1/4". Is there a special type or name for the flange that you recommended that actually fits inside the pipe? Where would I get one?Thanks for your time and advice, much appreciated.

They are called expandable PVC pipe flanges. They fit inside the drain pipe and are expanded with an Allen wrench so that they fit and seal. The drain pipe should be cut/ground down so that the flange will set on the finished floor. You might find these at a Big Box Store, but for sure at a "real" plumbing supply house, the kind that cater to the pros. They probably have them in your choice of designer colors!

Thanks Gary, I'll look for it at one of the local plumbing dealers!!

Also make sure the toilet sits exactly level with the wax ring and flange. If you ground the pipe, I doubt it's perfectly level with the floor, which itself may be slightly out of level. If anything's off by even a smidge, the toilet could be rocking in the wax ring. You won't feel it jiggle, but the uneven pressure on the ring can cause it to unseat in places and leak
.

flange

To do the job properly you need to install a cast iron flange leaded to the outside of that cast iron pipe that you tried to grind down. My dad told me to do it properly or don't do it. I think that's what you should do.....

Thanks for all the great advice. The cast iron flange leaded to the drain pipe may be a little out of my league though for me to tackle.

You said it was a 4" pipe, so you can use one of the internal clamping flanges. It basically fits inside the existing pipe, and you use an allen screw to expand the bushing to attach it to the walls and make a water tight connection. You should then screw it to the floor.