Replacement for bath trap leaking onto ceiling

[realnovice43]

Hope you can help me with a novice query - the current trap sits in a cut-out in the floor under the bath - so water can run directly onto the ceiling below and it did!. No matter what I do it's weeping from the thread on the connection to the waste.

I think it was cross-threaded at some time as it has been stuck on to the old waste with mastic so I want to replace it.

Waste pipe connects directly to the stack. The trap connects to the waste pipe by screwing onto a small piece which then connects to a push fit bend.

The local plumbers merchant told me the old trap was a P trap which was the wrong sort for a bath and sold me a McAlpine shallow trap which I now know has a 19mm seal that's too low. I see posts about 50mm or 75mm being the minimum and I'm not sure which I need.

Which of these is the correct way to go please?

1½" x 50mm Seal Bath Trap - Bath Traps - Traps | McAlpine Plumbing Products

1½" x 75mm Seal Bath Trap - Bath Traps - Traps | McAlpine Plumbing Products

Thanks

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[dontknowitall]

If you buy some ptfe tape (around £1.50) you can put a few turns (half dozen or so) around the rubber ring on the trap, then fit to bath. Best to remove the whole trap first, wrap the rubber ring, fit to bath then fit other end of trap to pipe in that order.

If this doesn't work it might be worth buying a new bath waste and new 1½" shallow bath trap and start again. (Fit bath waste first, then trap to waste, then trap to pipe.)

 

[garrywhite]

50mm depth of seal required if you are connecting to a stack.

 

[AWheating]

50mm min. id change the complete bath waste kit aswell as the trap for peace of mind.

 

[realnovice43]

Thanks all for this info, think I'll change the waste too to be on the safe side.

So I'm guessing 75mm would be better as belt and braces? As there is a P trap there presumably I could just get a replacement for that rather than specific bath waste like those in the link (there's a whacking big hole in the boards anyway)??

 

[wiggers]

I would change waste and get a mcalpine Q10 bath trap these are very shallow and would be ideal for you
And for ease if it does not marry up get a mcalpine flexicon 6 40mm!

 

[Guest123]

If its a plastic waste, take it out get rid and replace it with a metal one. Seal this to the bath with plumbers mate. Fit a Mcalpine trap with overflow to this first and then connect to the waste pipe and this will eliminate any chance of cross threading. This trap, waste combination will last for years if you install it properly.