Leaky joint in pipe

[BananaPie]

Help! We've just had a bit of a flood through the kitchen ceiling. Turned out to be a leak from a plastic joint in the pipe that supplies hot water to the bath and shower. The leak started at kids bath time, and we seem to have solved it by tightening the joint a bit. But what caused it? And what's to say it won't happen again while we're out

If it's a pushfit fitting it could be a number of things but I'd guess that it was probably either:

1. The locking collar wasn't done up. (Some have twist collars and some push in/ pull out)
2. No insert in the pipe.
3. The pipe wasn't fully inserted.

Of course it could be something completely different! I'd make sure that the pipe was fully inserted first. It could also be a damaged fitting.

I do not like the new plastic pipes, lazy cheap plumbing/plumbers.
Switch your water supply off at the stopcock, open all your taps to drain all the water out of the pipes and check the joint.
Undo the nut, clean any dirt off, make sure you put as much pipe back into the joint and tighten it properly. You shouldn't have any more problems with it then.

plastic pipe or metal?

photo needed.

Make sure you know where the stopcock is.

If you get a leak above a ceiling, make a hole in the ceiling with a skewer and put a bucket under it. Otherwise water will lie on the plaster, damage it, and make a bubble. If you are very lucky the kitchen sink will be under the bath and it might drip into it.

Thanks! Metal pipe with plastic joint. Tightened it by turning it a bit and it's no longer leaking. Just wondering how it got loose in the first place.

Pretty much what engineersthumb said.
Over time it just loosened with vibration.

Might be worth slacking off the locking collar and making sure that the pipe is fully inserted. If there is enough movement in te pipe then just slack off and push together. If however there is not enough movement it's worth disconnecting completely. If you have an immersion tank you will need to turn the water off at the header tank / stop cock and drain the tank (open a downstairs tap). If you have a combi then just turning off the stop cock and draining the line is OK.
I actually think pushfit fittings are quite good. I know people are a little dubious but it's been on the market quite some time and I don't hear too many horror stories. I use sI limonene grease when inserting the pipe into the fittings to protect the other rings, I also prefer the pipe inserts with two seals on the shank (barrier pipe only) though I've never had the normal barrel inserts leak and I've had some on the heating system 5 years.... I'll find a big puddle today I expect!