Bath Waste U Bend

[Alfie25]

I noticed a tiny leak coming from where the vertical black waste pipe directly from the bath connects to the white u bend connection. I unscrewed it and the rubber washer looks ok, so tightened it back up as tight as I could by hand and the leak has almost stopped completely but there's the tiniest bit of water weeping. Do I need a different type of washer, or should I apply some silicon - if so where?

Untitled

• Alfie25
• 18 Jul 2012
• 2

 

[TicklyT]

It may be the angle you've taken the picture from, but the fittings don't look very 'square' to me.

If there's any misalignment between the waste fitting and the trap, meaning you have to 'spring' the pipework to engage the union nut, or the mating surfaces don't meet squarely, then the joint will always be suspect.
Overtightening the fitting can cause the sealing ring to pop out of position.
Putting sealant on the washer lubricates it, making it more inclined to pop out of the joint as you assemble it.

Sometimes a leak at the joint between the bathtub and waste can run down the fitting unseen, and drip from the union nut, leading to the erroneous conclusion the trap union is leaking. A bit of toilet tissue wrapped around the waste fitting above the nut will help detect that.

 

[Alfie25]

You're right, it doesn't look very square. The camera was pretty straight as you can tell from the floorboards. The black pipe on the right of the U bend angles off sloping downwards so as you can imagine the U bend section that meets the vertical bath waste isn't perfectly straight. However, when I offer it up to the bath waste it does seems to seat ok.


When you say "Overtightening the fitting can cause the sealing ring to pop out of position." do you mean the union nut?


This whole bathroom set up is a complete bodge job!