Fitting Pop-Up Waste to basin

31 Jul 2005
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United Kingdom
I bought a pop-up waste unit to fit into the bathroom sink. I got the old one out and cleaned up the sink and fitted the new one with the new rubber seals.

Problem - water drips out of the bottom seal and into the vanity unit!!!

Do I need to apply any special substances to stop the leak or should I just keep tightening the waste until the leakage stops?
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Assuming you've fitted the waste properly :confused:, the problem may be that the base of the basin (whatever you do, don't call it a sink or this thread will never end) is not as "level" as it should be. I would add some silicon sealant to fill in any irregularities. But first check exactly where the leak is coming from - the pop-up lever joint quite often leaks, if not tightened enough.
9 times out of 10 a leak below a basin is due to bad design. Specifically, theres nothing to stop water running down the thread on the waste fitting!

You can get special washers which squish into the thread, but 2 rings of silicone work perfectly. Put it on the washer which goes up to the basin bottom to seal washer to china (sometimes not flat), and at the inner edge of the washer, to seal waste thread to washer and big nut.
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