Leaking basin waste

[aanicol]

Just fitted a new basin and all was well until the OH has noticed a leak.

After dismantling (there is no room to work behind the pedestal ggrr) I have found the leak to be from the waste (pop-up type) - see pic - the thread on the waste seems a bit short as the compression coupler hits the part which holds the rod to open waste and when its fully tightened there is a little play in the pipe below, tried ptfe tape but same result.

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• aanicol
• 29 Jul 2012
• 1

Any ideas ?

Different trap with a shorter thread ?
Any way to make the thread longer on the waste, extension coupler ?
Different waste altogether ?

 

[Gasop]

Have had this problem on a number of occasions.

Trim off the top couple of mm of the nut.

A wide blade saw is best and clean edges with a trimming knife.

 

[aanicol]

Thanks very much gasop, after several phonecalls to friends (and friends of friends) that very same thing was advised.

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• aanicol
• 29 Jul 2012
• 1

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• aanicol
• 28 Jul 2012
• 3

For anyone else who will probably encounter this if using it the tap in question is 'Cascade' by Cooke & Lewis from B&Q.

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• aanicol
• 28 Jul 2012
• 3

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• aanicol
• 28 Jul 2012
• 3

 

[45yearsagasman]

It'll be nice when it's finished

 

[TicklyT]

I would have just put a thicker rubber washer in the waste union (it's not a 'compression coupler')

The PTFE tape around the threads is pointless - the seal is (or should be) a rubber washer clamped between the bottom of the basin waste fitting and the top of the trap by the nut. The thread only holds the fittings together.

The nut will run further up the fitting than it should, and the fitting will leak around the threads if the rubber washer is absent. PTFE around the thread may mask the leak there, but it won't stop the water finding it's way between the base of the nut and the flange on the end of the pipe.

 

[aanicol]

I would have just put a thicker rubber washer in the waste union (it's not a 'compression coupler')

The PTFE tape around the threads is pointless - the seal is (or should be) a rubber washer clamped between the bottom of the basin waste fitting and the top of the trap by the nut. The thread only holds the fittings together.

The nut will run further up the fitting than it should, and the fitting will leak around the threads if the rubber washer is absent. PTFE around the thread may mask the leak there, but it won't stop the water finding it's way between the base of the nut and the flange on the end of the pipe.

I don't think a thicker rubber washer would have taken up the difference, I reckon about 10mm was required, although I never tried that so no way of knowing.
Bad design of waste I think as the part which takes the rod for the pop-up should have been a) higher, or b) a longer thread would have removed the problem.

I just got into the habit of putting PTFE tape on all threads, even when there was rubber washer(s) in the waste union (compression coupler ), will this pose a problem in future ?


Thanks for all replies.

 

[aanicol]

It'll be nice when it's finished

 

[longdogs]

Sometimes get the opposite with bath traps where the thread is too short to make a good connection.