Is there a tried and true method that is quick, easy and unlikely to crack tiles? Should I just use a masonry bit and hammer drill?

Unfortunately when it comes to rectified porcelain floor tiles drilling holes are really difficult. You have no chance with a masonry bit on a hammer drill.

I would consider two alternatives.

First and easiest is to use diamond bits. They do sell small diamond bits like 3/16", 1/4", 5/16" and they are tiny hole saws. They work good but burn up quick so keep spraying water on build a dam around with putty.

Another way is to use an angle grinder with a diamond blade to cut away two notches where your screws run through. Your flange still sits over the tile but where the screws are notch the tile out. Your toilet will cover it and won't be seen.



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I use diamond bits. Make sure you use them in rotary mode only in the drill - no hammering! The hammer is only for masonry with carbide bits.

Other trick to keep them from “walking” or slipping is to take a scrap of wood say 1/2” thick. Drill a hole in it the same size of your diamond bit. Now, mark the spot you will drill with a sharpie. Place the board’s hole directly over the mark. Now hold that board down with one hand and drill the diamond bit with the other hand. Once you’re a little bit deep into the tile, remove the board and put the diamond bit into the hole and keep drilling. It won’t slip around.

You will want to take some breaks anyway while drilling prorcelain to let your drill bit cool off. With my 18v cordless drill, it probably takes me 5 mins per hole but I take my time.



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I use glass bits. They work pretty well.

Agree 100% with steve_g on the glass bits....they don't walk and drill a nice clean hole with no cracking and no hammering necessary. I use them on all types of glazed tile and they are the best.

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Not a plumber by trade but a fierce DIYer

I have tried glass bits on rectified porcelain tiles and I have had no luck with them. Ceramic tiles yes, but porcelain tiles the only bits I tried that was able to make a dent is diamond bit or diamond hole saws and it takes a LONG TIME. I swear I think it took me longer to drill through a rectified 3/8" porcelain floor tile then the same thickness granite!



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I'm surprised, I've used them on porcelain bath tile (wall and floor) with no issue. The point of the bit has to be sharp, old bits don't cut it. Once it bites through the glaze the drilling is easy.

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Not a plumber by trade but a fierce DIYer

I think depends on the porcelain tiles. Some porcelain tiles are very hard. I had some where I wanted to drill 3/4" holes for hot and cold supply lines behind a pedestal sink, and I didn't want to spend $50 on a diamond hole saw bit so I took it to a tile store where they had all the tools and will do odd cuts. They looked at my tiles and said it would take too long with their drill press and offered to make two notches with their wet saw instead for $10 each notch. I passed.

My experience is that I've seen them sold in either chrome or black. The black ones work for me, the chrome ones don't.