Bath pipe keeps coming away an water comes through kitchen ceiling

[Adda]

Hello
Just looking for a bit of advice please. Bath waste pipe has a join that over time has come away and when it does water is going straight down the walls dripping form kitchen ceiling below.
Got a plumber to look few years back who put the pipe back together an said it shouldn’t happen again.
Well it did last week an now when I check the join, I can push it together and it will work but it’s not watertight and comes away no matter how much I tighten the ring bit.
would appreciate any advice. Is there anything to seal the join or do I need to get the pipe replaced?
I’ve added a couple of pics.
Many thanks guys
[automerge]1582470172[/automerge]

sorry pics upside down for some reason on original post

 

[ShaunCorbs]

Is there a black rubber piece inside the compression end of the fitting eg where the pipe goes in if not you’ve lost it somehow / hasn’t been put on

if you haven’t

https://www.NoLinkingToThis/p/mcalpine-s23u-multifit-blanking-plug-white-32mm/73053

Then install / in this order

 

[Adda]

Nothing like that mate. Just the red bit. Don’t think it could have ever been there unless when it last broke its disappeared under the floor boards.
cheers for answering.
do I Just need to get a rubber seal then?
Thanks

 

[ShaunCorbs]

Nothing like that mate. Just the red bit. Don’t think it could have ever been there unless when it last broke its disappeared under the floor boards.
cheers for answering.
do I Just need to get a rubber seal then?
Thanks

yes and just re make the joint and tighten should be good then

 

[Adda]

yes and just re make the joint and tighten should be good then

Absolute legend mate! Thanks so much. Will do this an hopefully can trust it again. Might wrap some tape around the two pipes as well as for good luck as there must be some pressure nudging them apart over time.
cheers again mate for the advice

 

[ShaunCorbs]

Absolute legend mate! Thanks so much. Will do this an hopefully can trust it again. Might wrap some tape around the two pipes as well as for good luck as there must be some pressure nudging them apart over time.
cheers again mate for the advice

tbh I wouldn’t put tape on them but once made up try to pull them apart slightly shouldn’t come out

 

[Stigster]

I know you've not got the black rubber seal but there's a fair chance it's been pushed right to the back of the socket inside the fitting. You did say you've pushed the pipe into the fitting already and doing that with the nut in place almost always shoves the seal right to the back where it's hard to see.

Just in case you haven't looked right down into the outer rim of the fitting to see if it's down there. If it is fishing it out often damages it so you may need a new one to fit anyway as per Shaun's excellent advice.