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What's the best drill bit to drill a 5mm hole into the 15mm-thick side of a vitreous china WC (toilet tank) or toilet tank cover. Once drilled, I'll insert a flexible water tube through the hole to connect the water outlet inside the WC to the bidet using a T adapter (3-way valve.)
Hi it's 2025 and I encounter the same problem, hope you guys are still around doing well!
So here's the photos of the toilet in question. The water point is inside the cistern, the plumber doesn't want to drill a hole for me saying it's risky to damage the ceramic.
So I'd need to either drill a hole on the lid or the tank (which is thinner than the lid) so I guess it's easier, but I will have more trouble if it is the tank I break. I wonder which would be the better way to do?
I have not yet made purchase for the smart bidet seat. Do they come with standard pipe diameter so the 8mm drill would work better?
I don't even have a drill, are there any recommendations what to get for this project?
Also, some plumbers told me I might need to get them install a NPZ valve for me, but bidet websites says as long as the bidet seat is watermark stamped and I get the seat douche /douche outlet 25mm over the overflow of toilet bowl I'm all good. Have anyone encountered problems with it or it's naturally in compliance?
Many thanks and appreciate any feedback!
Hello @DannyPoon
Welcome to the Bunnings Workshop community. It's sensational to have you join us.
Please allow me to try and answer some of your questions.
- Between the cover and the cistern, it is easier to drill into the cistern as it has a thinner wall. If you plan carefully and take your time you should be able to drill through your cistern wall. There is always a risk when drilling through porcelain, but if you take your time and not rush the process you minimize that risk of damaging your cistern wall.
- Your bidet seat will come with its own pipework, I suggest doing a bit of research in regards to what kind of bidet seat you want installed. Once you've decided you'll know what size drill bit you'll need for the project.
- If you're only going to occasionally use this drill, then It's ok to get a budget set like the XU1. But if you would like to invest in a mid-range set you can't go wrong with an Ozito or Ryobi set.
- In regards to installation a non-return valve must be installed, and its's best to have the seat installed by the plumber for safety and compliance. I recommend doing a little bit more research in regards to the brand and quality of the seat you'll be installing. For example, the Evekare set is not just known for their bidet seats but for their assisted living products as well. Caroma is also a well-recognized brand and has been providing quality bathroom products for many years. You can also look at the reviews about the product itself and see what others have said about it.
My best advice is to arm yourself with information in regards to the item you are about to install. This will help reduce the amount of doubt you may have in regards to installing a bidet seat.
If you need further assistance, please let us know.
Eric
