What should the hole size be in a basin for taps

19 Jun 2005
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United Kingdom

I've just bought a new bathroom suite. Having problems fitting the basin taps. The problem seems to be the holes in top are too big and the tap will not sit properly. The hole is approx 30mm diameter the threaded part of basin taps is about 20mm. It rattles around in the hole, and will not seal properly when tightened down. I tried a bath tap and even that has a fair clearance but sits and seals properly to top of basin.

I compared the basin hole to bath and it is almost identical. My suspicion is its been made overseas and perhaps they use larger holes.

So far my only solution seems to be to fit bath taps to both basin and bath.

I looked for technical specs for sinks and they never seem to show the holes size. anyone find a link or know the correct answer?
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welcome to the world of plumbing jim. It's a curious thing that basin taps do not fit properly into basin holes. At least not without the installer using some ingenuity. I often wonder myself why such a ridiculous situation continues.

My own solution is to fit a thick tapered rubber washer underneath. The ones I use are imported from Italy (ingenuity or what?) and would not be readily available to you, but I've heard that something similar is available here, for a hefty price (for a washer).

No doubt someone will post info. on this in due course.
I did actually try using a bit of pipe insulation and stuff it around the tap but it wasn't very efficient. The hole is just way to big, the washer from standard size basin tap on overlaps the edge a couple of mils all round the bath tap fits almost perfectly.

I found armitage shanks specs which show how far apart the holes are but not the actually diameter. At end of day if it means I get a watertight seal on sink top I will fit the baths taps instead.

Going to have quick look round tomorrow and check hole dimensions on other sinks. If the one I have is far larger then I would have a case under section 13 of SofG Act. (must be fit for purpose) The taps were supplied as part of suite and should therefore fit without requiring modification. I might request they suply me with a free set of bath taps.

If that does not work, then I may resort to using a hole saw and make my own large washer. Can't believe there is not an industry standard for such a simple thing. After all basin and bath taps are a pretty standard size.
Go to a decent Plumbers Merchant and ask for Fix-A-Tap. Its a kit designed for this problem, comes for basins, baths and sinks
Hope this helps
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Yes, stupid isn't it. I have at times wound lots of insulating tape round the tap's thread to centralise it in the hole. Then fill the whole hole with silicone - then the tap won't rotate either.
Fix-a-tap I've not used, but I think Andy-Plum has them online.

These solve halfthe problem:
jim4bb said:
fred67 said:
Go to a decent Plumbers Merchant and ask for Fix-A-Tap. Its a kit designed for this problem, comes for basins, baths and sinks
Hope this helps

Found what you mean here;


They also do them where I bought the suite from. Helps if you know what they are called.

Bought an Essex fix-a-tap today, takes a 32mm hole down to proper size for basin tap. Works a treat, comes with rubber grommet for tap and rubber washer for underside of the basin. Grips tap really well and stops it twisting.

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