A common problem when laying new floor tile is the change in elevation that occurs and results in the toilet sitting too far above the closet flange. Some people use a double wax seal and this may work but I wanted to raise the closet flange for the toilet instead. I needed to replace the plastic flange as when the tile was put into place the worker had pushed thinset underneath and the thinset pushed up the flange at certain points to where there was not longer a flat surface for the wax ring and the toilet rocked.
My bathroom situation was compounded by the original contractor having added particle board to raise the elevation of the vinyl flooring to the same height as the adjoining bedroom carpet on padding. The new tile sat one full inch above the original plywood subflooring. I decided to remove the excess tile and the particle board and create a flat surface to add a spacer and then the new metal toilet flange.
I thought long and hard about how to remove the tile and thinset around and underneath the closet flange. I tried using a hammer and chisel but made little progress. I thought about using a hammer drill but was worried about cracking the tile and making the job even bigger. At some point I decided to try grinding the thinset and tile down using a small 4.5 inch angle grinder. I bought a dtec brand continuous rim diamond blade that has a "turbo" edge for faster material removal. It was not expensive and worth a try.
I first tried using the angle grinder with the dtec diamond blade like a cut-off blade with the grinder at a 90 degree angle to the tile. It was easy to control the dtec blade thanks to the continuous rim. It was much easier to control than a grinding wheel or a cut-off blade so my choice was a good one.
At some point I realized that the grinder and blade would work better if I used it like a plunge router with the tool parallel to the tile and gradully lowering the diamond blade to remove first the tile and then the thinset and finally the particle board until I was down to the plywood subflooring.
This approach made it very easy to control the grinder and cut exactly where needed.
The result is shown in the picture with the tile cut-out shown along with a blue circle to show how round an opening I was able to create for the new toilet flange. The ragged hole created by the original rough plumber (and rough is an apt description) was clearly made by a sawzall. I have known plumbers who say they don't need a large hole saw and can make any hole they need with a reciprocating saw and save time. I doubt they save much time and they certainly leave a poor support for the closet flange (and a lot of drafts and pest entry points from sink drains in wall openings as well).
The next step was to add one or more spacers. I say one or more as the standard ones I found at a local builder supply store was 0.4 inches thick and are meant to be stacked with a layer of adhesive caulk between each one. As the closet flange is designed to sit on the subflooring I decided to instead make a spacer using a scrap piece of inch thick plywood subflooring. I needed an outside diameter for the spacer ring of 7 inches and an inside diameter of 5 inches. If you think that this was a more difficult and time consuming approach you would be mistaken.
Since first adding a Hole Pro adjustable hole cutter to my home shop I have found it makes fast work of projects that would otherwise take much more time and effort. I took my Hole Pro X-230 which cuts holes from 1-7/8" up to 9" in diameter and inserted it into my little 1/2 HP drill press set one blade at 5" and the second blade at 7" and then clamped down the scrap piece of inch thick subflooring. Even with the moderately powered drill press in a couple minutes I had the ring cut out from the plywood and had my spacer in hand.
I used a waterproof wood glue and placed the plywood spacer ring into the opening and on the subflooring.
Last step was to take some 2-1/" long #12 screws and drive them through the new toilet flange and the plywood spacer and into the plywood subflooring.
The end result was a closet flange that is 1/4" proud of the tile floor.
I put down a single wax ring, mounted and bolted down the toilet and it fit perfectly. Perfect seal and no rocking and no gap between the toilet's base and the tile floor.
Some may question using a wood spacer but the original subflooring was the same type of plywood with the same type of glue between the wood layers and provided a more solid support and better holding for the wood screws. I have read of people recommending the use of spacers to level a toilet over the flange and to then caulk with standard caulk or even thinset. I do not view this as a sensible approach. If there is water leakage around the flange I want to see it coming out from underneath the toilet and not having it sit and gradually seep down through the wood subflooring which is a sure recipe for dry rot and a much bigger and more costly repair job in the future.
I spent more time researching possible approaches to take than I did actually doing the work. It took less than an hour with the angle grinder and the dtec diamond blade to correct the work of the tile setter. It took less than 10 minutes in total to make the wood spacer (though luckily I had the scrap piece of inch thick subflooring at hand). Gluing, pre-drilling the holes, and screwing down the closet flange took about 15 minutes. Add in 30 minutes of setup and cleanup time. Next time it will go a lot faster and I know I will be using the angle grinder with the dtec diamond blade and the Hole Pro X-230 to do it quickly and do it right.